Herewith a commentary on some work I have been doing on the Vectrix Charger Programming.
I have achieved a limited success in the task of re-arranging some of the charger's performance. This has been with the object of reducing the battery 'damage' whilst charging and also, hopefully, to extend the life and therefore the mileage of the battery before replacement becomes necessary.
It is my view that most of the damage to the battery is caused by heat, and that heat is generated / produced by two means. The first is the heat of the charging process and the second cause is the internally generated heat produced by the battery's internal resistance when current is drawn from the battery.
So far, I have concentrated on the charging process. My aim was to reduce the initial charging current, maintain that current to around 80% of 'full' capacity (24 Ah) and then continue the charge with a further reduced current for a sufficient time to complete the charge process. There will be a 'side effect' of this which is a longer charge time, however, I consider that a longer charge time might be worth accepting if a longer battery life results from this. Bear in mind that charge time, including equalisation, can extend to over eight hours with the Vectrix programme/software.
In terms of the initial charge (up to 80%), reducing the current to 6 to 7 amperes only increase the charge time from 2hrs (empty battery) to 3.5 hrs. This is an increase which I am prepared to accept.
The second stage of charging which involves the ''tr' cool off periods, lasts for one hour, in the earlier software (Version 2012 and thereabouts) this also involved a low rate charge of 3amps. In the 3001 version, this was reduced to zero charge and still runs for the hour (I believe that Vectrix had noticed that the 'tr' at 3 amps was actually causing further heating of the battery).
The third stage of charging is the C.C. (constant current) stage which runs for a preset time or until a preset voltage is reached or until the battery heats up to a preset maximum temperature.
A final charge stage involves the process of Equalisation. The purpose of which is to bring any cells which have 'fallen behind' in terms of charge (i.e. they are not 'Full' whilst other cells are full) up to a genuine fully charged condition.
The main heat producer during the charge process is the latter part of the initial stage ( the part that takes the battery to 80%), this is followed by the Constant Current charge at 3 amps which also produces excess heat. The Equalisation current level is also excessive and contributes yet more heat to the battery.
Vectrix 'engineers' recognised the problem but failed to deal with it mainly due to their over-qualification for the job which they were doing. A common problem with overqualified engineers is that they are full of theory and short on practice. As anyone who is involved in troubleshooting knows, theoretical knowledge and practice experience can often be very difficult to marry together and in all cases, what happens in practice is far more important that what should happen according to theory.
Vectrix engineers attempted to solve the heating problems by 'cooling' the batteries (the plenum chamber fans). They added periods of 'cooling' to the process (the tr.with no current in later software). They programmed in a temperature limit, beyond which the charge was halted and the fans were kept running, but they completely failed to realise that the best way to deal with the problem was to NOT generate the heat in the first place. They were, of course, far more interested in selling a short recharge time that would appeal to buyers. A VERY BIG MISTAKE.
Where does that leave us? Well, working on an earlier version of the software ( I wanted tr. with instruments lit up), I have been able to make a number of alterations to the programme parameters without actually altering the programme routine itself.
I have reduced the initial charge current (C.P.) 6 to 7 amperes (864 watts) and reduced the 'aiming' voltage so that C.P.144 is the voltage limit for the initial charge. At a charge rate of 6 amperes, 80% charge occurs at approximately 144Volts.
I have reduced the 'cool off' current to 1.5 amperes. The 'aiming' voltage is set, within the programme, to equal the C.P. voltage.
I have reduced the Constant Current level to 1.5amperes and increased the maximum time to 4hrs and may yet need to add more time (it was set to around 3.5 previously)
The above changes do increase the charge times, is there really any choice?
Vectrix had set some 'safeguards' in the programme. I have used the word 'safeguard' rather loosely. They had set the maximum battery temperature to 50 degrees Centigrade. By the time that the battery casing, where the temperature is measured, reaches 50 degrees then the internals of the battery are considerably hotter. I don't call that a safe limit.
If the charger 'control' failed then they had a 'safe' limit of 15 amperes and a maximum charge of 32 ah in C.P. mode with a 35 ah absolute limit. What they did not consider was that if the programme 'locks' then even these limits will not help as they will not be applied due to the locked programme.
If the battery temperature exceeded 40 degrees in use (when riding) then the plenum fans where switched 'on'. At 40 degrees C on the battery case, when in use, the damage is already done, as I have already said theory and practice ...?..?..?....?
So much for the Vectrix engineers 'safeguards'
I have incorporated 'safer' limits into the software which I am altering. I have reduced the maximum charger output to 8 amperes. I have arranged for the plenum fans to be always 'on' when the bike is being used. I have set the safe maximum battery temperature (when charging) to 25 degrees C ( it is currently 5 degrees outdoors here just now and rarely exceeds 20 degrees) and I have reduced the maximum ampere hours in C.P. mode to 24.
All in all, a number of changes and hopefully for the better.
The above changes are currently being tested and have so far proved to work as intended. It will be a while before the real effects (a longer battery life with fewer imbalance problems) are available.
The above 'work' has taken longer than I expected, but reverse engineering, in order to find out how a programme works, is not the easiest of subjects and I am still a novice. I have done nothing illegal, all I have done is to make alterations to an existing hex file for my own benefit. I am willing to share my knowledge with you individually so that you too can benefit if you wish. The alterations which I have made can be varied to suit individual requirements (not easy but not too hard either).
This is not a simple process, but I will try to help anyone out there who may be interested in this work. Basically, I have made the alterations directly in the Hex file which is programmed into the bike with the Vectrix Diagnostic Software. The changes to the hex files are written for a specific version and cannot easily be 'fitted' in other versions. Because I have 'downgraded' to an earlier software version, I have lost the estimated mileage readout on the left-hand display and the battery capacity meter (right-hand display) no longer decrements. I have found that the left brake pull that gives the voltage and temperature readout allows me to estimate the remaining battery capacity and I have not been caught out yet.
I am hoping, in due course, to reverse engineer the whole programme. When that is completed, I shall write my own programme to deal with the problems in my own way and will publish the programme as freeware (but that, folks, may take some time)
Dear People at Vectrix,, (I know that you read this column)
Why don't you contact me so that WE can work out YOUR problems together and benefit YOUR business and YOUR customers and perhaps the environment at the same time? I don't even want paying, (although you might like to contribute towards the £150 worth of books I have bought) all I want is a good reliable product. You have nearly achieved that, why not allow me to help you finish the job properly? Contact me through this forum, PLEASE. :-)
And having got that over folks, Merry Christmas and a Happy new year to you all, even to those people at Vectrix.
Keep smiling folks:-)
Fabulous, well done!
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Well done Sally :D
If you also down grade the MC software to MC1014b, both the fuel guage and estimated range will work again.
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
This is very interesting, but I have no computer experience. How would someone such as myself modify the software? Thanks for the post.
The laird... fantastic work! they should employ you at the vectrix factory. ;-) Do you think it would be possible to switch "on the ride" between two different charging programs, one fast and agressive (the present one from vectrix), and another slow to take care of the battery (your version)?.
Re-arranging the Vectrix charger behavior
Now that it is possible to make (some) changes to the Vectrix Charger Programme, it would be best to spend some time reasoning out what changes to make and why, exactly, we want/need to make them.
I have been making good use of a number of information sources regarding the NiMH cells/batteries. Two excellent published sources are those by Duracell and EverReady plus a number of other more general works from various sources.
The battery failures have, as far as I can establish, all been caused by imbalance of the cells followed by overcharging of the cells with a higher than average charge content and voltage reversal of the cells which had a lower than average charge content. In some ways, the imbalance of the cells is the biggest problem, there are other problems.
Dealing with cell imbalance
The question of how the imbalance occurs is important and it is my considered opinion that the cause is simply down to cell temperature differences throughout the battery. These differences occur due to various causes including internal heating both in use and whilst charging, and also by the heat of the sun which may be direct sunshine or reflected/radiated heat from road surfaces / buildings etc.
The problem here is not absolute cell temperature, it is the DIFFERENCE in temperature between the cells. When the cells differ in temperature they also differ In their internal losses and it is this that causes some cells to become 'out of step' in terms of charge when compared with the other cells The best way to tackle this problem is to always have the plenum fans running whenever the cell temperatures vary cell to cell and whenever the battery is either being used (bike in action) or when charging the battery. The only way to tackle the atmospheric heating is to choose where you park/keep the bike when it is not in use.
We can do a lot to prevent the problem of imbalance occurring. We have some choice as to where we park / keep the bike and within the charger programme there is the facility to run the plenum fans whilst riding and there is potential to have the fans run for a predetermined time after switching off at the end of a ride.
Heat Generated during Charging.
The charging process generates heat. More so in the NiMH battery because of it's chemistry. However, the heat generated is not excessive during the earlier part of the charge cycle and from the available information this 'earlier' part of the cycle extends to about 70% to 80% of the full capacity. The charge rate of 10 to 11.5 amps is not a problem in the early part of the re-charge cycle but once we pass the 70% / 80% point the heat generated by the charging process increase dramatically and it is essential to limit the charge current in order to maintain the generated heat at a manageable level. This too, is possible via changes in the Charger software.
The latter part of the charge process, from 70% / 80% onwards can be carried out at a lower current rate ( around 2 amps? ) to complete the recharge process in about 6.5hrs maximum discounting any pre-charge cooling. The charge times being about two hours for the initial stage (at 10 / 11 amps) and the follow up stage (at 2amps) talking another 4.5 hours.
The Bulging cell syndrome
One of the interesting items, contained in the EverReady literature, seems to answer a question which has puzzled some of us for a while, and that is the matter of the 'bulging' cells. Why do some cells bulge? Are they the ''faulty' cells? What caused them to bulge? Well, the answer is quite simple. The EverReady literature show a graph of cell Pressure / Temperature / Voltage whilst being charged. What is painfully apparent is the massive rise in cell pressure which takes place beginning at the point of (about) 85% to90% of capacity. By the time the cell has been overcharged by only 10%, the voltage has peaked, the temperature has risen and the cell pressure has (relatively speaking) gone ballistic. So now we know the reasons for the 'bulging cell syndrome'.
The errors that Vectrix have made are now becoming more clear. Their method of charging appears not take account of cell losses in storage through high temperature effects. The idea of 'equalising charges' to correct the imbalance problem is not a good one due to the potential damage to overcharged cells which does occur during the process. Pushing the high current until the cells reach 1.5 volts during the initial stage of charging is potentially disastrous to cell life due again to the effects of excess heat and pressure within the cell.
Allowing the cell temperatures to rise significantly, due to excessive charge current levels and/or overcharging adds to the problem and is easily prevented. The temperature 'cut off' point of 50 degrees centigrade, used in some of their software, is far to high and takes no account of the ambient temperature or of the difference in the cell to ambient temperature. A cell at 50 degrees in an ambient temperature of 45degrees does not necessarily indicate a problem, but a cell at 50 degrees in an ambient temperature of 15 degrees is in serious difficulty. We can change the maximum / cut of temperature within the software and I propose different levels of cut-off for use in different ambient temperature areas.
The idea of measuring the current/power used and then, when charging, attempting to 'replace' the used power is an interesting one but not, in my opinion a practical one as it does account for temperature related losses. Whilst it may be an ideal, it is definitely not practical but it is incorporated into the some of the Vectrix software. Whether it constitutes part of the problem is another matter. On the good side, this feature can largely be circumvented by simple software/hex file changes.
As I said in my first post on this topic, I have made a number of changes to the hex files (software Revision 2012) and they are being tested, so far without any failures. The plenum fans are already running under all usage conditions (and continue for twenty minutes after switch off). What I propose to do next is to determine suitable cut off voltages for the different charging stages and, when they are tested and proved to work, I shall make available the codes and information as to how to install them. Anyone with the Vectrix diagnostic software and adapter will be able to complete the required changes quite easily.
So far, the disadvantage (due to my work being on the 2012 version software) is a loss of the estimated mileage and fuel gauge (caused by an incompatibility between the 2012 charger software and the version 1017 motor controller software. I am reliably informed by Matt that the fuel gauge and estimated mileage can be regained by installing the earlier motor controller software. This is correct, but I prefer to have the 'left brake/kill' switch combination which gives the voltage and temperature readout which only comes with the 1017 motor controller.
Some questions that have already arrived on the forum.
Oobflyer, I will provide an instruction sheet, whereby anyone with minimum computer skills should be able to perform this task. You will, of course, need the basic tools of a can bus adapter and computer, all else I can provide.
'R', To change from one 'charge rate' to another will entail reinstalling the hex files for each change required, so far I am only able to modify the existing hex files, re-writing the charger programme is still some way off. However, the idea of using the 'aggressive' charge rate on occasions is not one that I would recommend. Lowering the initial charge current, perhaps to make use of a limited current supply, could be both practical and useful, but that is quite a different matter.
How will the changes be made? I thought that you would ask that one so here it is:-
Basically, you need to open the hex file entitled BCR2012 in a text editor. It should look like this. BUT BEFORE YOU DO, SAVE A COPY AND KEEP IT SAFE.
This is, of course a tiny part of the whole file!!!!You can find this section by doing a 'search' for '102f9'.
Line 102F9 must be identical to the one shown in the above code piece before you change anything. If it is not then do not proceed.
If you change the line which starts with 102f9 (middle line in the above file fragment) to the following:
(The changes are in bold print to make them easier to locate. Do not embolden them in the file). And Now Save the file, you have a modified file (I suggest you use a new name for the file)
When/if this new file is installed, you will find that the charger will output between 6 and 7.5 amps for the C.P. Stage of charging instead of the usual 10 to 11.75 amperes.
Replace the file with the 'old'/unchanged version and you are back to 10 / 11.5 amp charging.
I am not suggesting that you actually do this, by itself it doesn't achieve very much, if anything. What it does is to demonstrate that this script is not a lot of ''hot air' and it shows that it is possible to change the file if indeed that becomes necessary.
Mistakes in the hex file are not (generally) tolerated. If the checksum is not correct through a typing error for example, then the file will be rejected by the diagnostic software with an error message of 'checksum error'. If you do get a mistake to pass through the diagnostic software it is more likely that the charger programme will hang rather than do any damage. DAMAGE COULD OCCUR HOWEVER AND I ACCEPT NO RESPONSIBILITY FOR ANY CONSEQUENCES.
Everything that I am writing is carefully checked, provided that the codes are correctly changed as per the given instructions there should be no problems. We are at this juncture because Vectrix have failed us and some of us are trying to help others to deal with problems as we see them. Those of us who are trying to be helpful cannot take responsibility for the way the information which we provide is used. I will go so far as to say “this is what I am doing and this is why I am doing it. You must do as you see fit, whilst I will offer any help that I can, I don't accept any responsibility if things go wrong”
These changes are specific to the 2012 charger hex file. Don't attempt to change any other file with this information.
I shall be back with further script when tests and calculations are completed.
Best wishes and a Happy New Year to you all.
I actually quite like the idea of measuring the amount of energy pulled from the pack.
It allows you to charge fast with no chance of overcharge, and charge slowly later to replace self discharge losses.
Its the idea of resetting the count at red battery light, but still charging fast that gets us into trouble.
Have you a way to get the charger to follow a constant power than constant voltage charge profile?
I wonder what the chargers max power output is at 240v.
Thinking of those who have moved to lithium here.
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Results of early Testing of the Charger Programme Changes
I already have a battery problem. For the latter part of last year (2010) Capacity has been down to around 18Ah. This is between the Vectrix chargers 'Red Light' and 'Full' following a normal charge by the Vectrix charger. I know this to be the case because I am checking via a memory dump and the use of the 'Download template' which gives this useful information.
During both riding and charging, I was noting battery heating. Again, using the diagnostic software, It was noted that the temperatures between the twelve battery sections / blocks were at considerable variance with each other and also, especially under charging, were well above the ambient temperature, sometimes by as much as 10 to 15 degrees C. by the end of charge. On occasion, the battery temperature reached 28 degrees C just as the 'red light' appeared whilst riding, and this in an ambient temperature of only 15 degrees C.
Following the work on the Hex file changes I have applied a number of changes to my charger software (via the Hex file) with some quite interesting results, Incidentally, I have recently changed the Plenum fans for 'computer type' fans. The 'new' fans only use 24watts total as against the original 'impellers' which consume a regular 60watts. The plenum fans are 'on' whenever the bike is either switched 'on' or being charged, they also run for some ten / twenty minutes following 'switch off'. In my view the constant gentle breeze through the batteries is better than the occasional gale.
Yesterday, starting with a 'full' battery I took the bike out for a run of 20 miles until the 'red light' appeared. The battery temperature had begun to rise 'by 3 degrees C' just prior to the 'red light' indicating that the 'poorly' cells were empty and probably running just into reverse voltage. On my return home, a memory dump was taken which indicated that I had used 15.14 Ah at an average current of 15.85 Amperes. This, on a journey which included a 250mtr climb and a 250mtr descent and 12 miles of relatively level riding.
I have reprogrammed the charger to provide the following:
C.P. = 140v (because of the temperature compensation it worked as C.P.141)
Current = 6 to 7.0Amperes.. (Constant power =864watts)
Tr = 140v (it is 'tied' to the C.P. 'aiming voltage' so it is same as C.P. Level)
Tr Current = 1.5Amperes.
C.C. = 144v (became 145v due again because of temperature compensation).
C.C. = 1.5Amperes. (this is 'tied' to the Tr current level)
C.C. Time = 4.0Hrs Maximum
E.Q. = 144v
E.Q. = 1.5Amperes (Tied also to C.C. And T.r. Current Levels)
E.Q. Time = 3Hrs Maximum.
In all of the above, when the battery reaches either the Set Voltage levels OR the Time limit, the charger moves on to the next mode of charging. The exception is E.Q. Which only switches in every 12 hrs of riding/usage (or something like that. So far I have simply not allowed things to get that far).
I well appreciate that the above settings look very low when compared with the original Vectrix settings but they resulted in the following charge pattern. The 50% starting point was used to account for the 'good' cells being only 50% discharged from their 'full' state. The 'faulty' cells were obviously 'empty' which accounts for the 'red light' and as I have no wish to overcharge the good cells, the faulty cells are left to charge / discharge within their own capacity, hopefully they will improve with time.
The charger was connected to the mains supply and ran as below:
Time Batt Volts Charger V Charge Current %Charge Batt Temp.
0 131v C.P. 141 6.7Amps 50% 11.0 C
20mins 136v C.P.141 6.4Amps 57.5% 11.0 C
40mins 138v C.P.141 6.3Amps 65% 11.0 C
60mins 139v C.P.141 6.2Amps 72.5% 11.0 C
80mins 140v C.P.141 6.2Amps 80% 12.0 C
In the following ten minutes the Battery voltage rose to 141/2 Volts, the temperature rose to 12.0 C and the charger moved on to the Tr mode.
105mins 140v Tr.141 1.5Amps 12.0 C
120mins 141v Tr.141 1.5Amps 11.0 C
135mins 141v Tr.141 1.5Amps 11.0 C
150mins 141v Tr.141 1.5Amps 85% 11.0 C
The charger then moved on to the C.C. Mode.
150mins 141v C.C.145 1.5Amps 11.0 C
210mins 141v C.C.145 1.5Amps 90% 11.0 C
270mins 142v C.C.145 1.5Amps 95% 11.0 C
330mins 143v C.C.145 1.5Amps 100% 11.0 C
For some unbeknown reason the charger then switched to E.Q. mode. I am looking into this one but have no result yet.
330mins 143v E.Q.145 1.5Amps 11.0 C
360mins 144v E.Q.145 1.5Amps 11.0 C
420mins 145v E.Q.145 1.5Amps 105% 11.0 C
Again for some unbeknown reason the E.Q. mode started as a 1Hr countdown (another one to investigate:-))and I was able to observe the last few minutes on a minute by minute basis.
At the end of the charge cycle the plenum fans ran on for a further twenty minutes (one of the changes I have made) and the battery temperature was checked after a further one and two hours. The battery remained at 11.0 degrees on both checks and was still at 11.0 degrees this morning.
The percentage charge input is by my calculation. The diagnostic software also gives a 'last charge' figure which indicated that the battery had only received 9.5Ah. However, I used the bike today and traveled twenty two miles using 14.32Ah and didn't get the 'Red Light', what is more, the battery temperatures started out at 11.0 C rose to 12.0 C (on the first hill-climb) and returned to 11.0 C by the end of the journey which included a 250mtr climb, a 300mtr climb and matching descents. Right now, I am a very happy Laird..
There is still some work to do on the programme changes BUT, what I have shown is that the changes can work AND they work to my satisfaction.
From the table above it can be seen that the temperature of the battery remained (almost) constant throughout the charging process AND what is more important, the battery temperature was only 3.0 Degrees higher than the ambient. Further, by observing the battery module temperatures using the Diagnostic Software, the module temperatures were all within 0.3 Degrees of each other for the whole process..
The 15Ah which I had used on the preceding ride was replaced in a total of 7Hrs. A 'full' Charge (100%) would require 8.5Hrs. However, something like 10% to 15% of Capacity is not usable due to the Vectrix 'system' and Imbalance problems, so in practice even using my low figures a 'full' recharge (from 10% to 105%) would take about 8Hrs and an 80% charge, assuming that you can't get below 10%, would take only 3.5Hrs.
As an interesting note, the battery charging data which I have indicates that the early part of the charge can be undertaken at higher current levels without damage or undue battery heating. I shall experiment with higher 'initial currents' (in the C.P. mode) as and when I get around to it. It may be a while yet as I still have a faulty battery to get back into good order. I am hoping, of course, that my new charging routine may provide some improvement in the current condition of the battery.
Some questions answered.
The charger output can reach 15Amperes because that is what Vectrix set as their 'maximum current level', Whether it can sustain that for a full charge cycle is not certain, but could be tried. 15Amperes at 154Volts would equate to 2.3 kilowatts, you may be asking a bit too much of it. 2.0 kilowatts might be a reasonable test figure?
Measuring the output (used ) power and 'replacing' it when charging certainly seems a good idea BUT as stated already, the software registered only 9.5Ahrs replaced on that last charge of mine whereas my calculated value was 16.5Ah. Being as it used 14.5Ahr today following that last charge and with no 'red light', I am inclined to think that the programme's calculations are not that accurate. Further, if I had allowed the charger to 'replace' what it thought was 16.5Ahr, by calculation it would probably 'stuffed' my battery with a total of 28.66Ahr with disastrous results?
I haven't studied Lithium chemistry / technology but, the Vectrix Charger does use a Constant Power charge for the first (C.P.) part of the charge cycle. This could be available for the whole charge cycle if required but it doesn't sound like a good idea to me. I would prefer to consider the whole concept of charging Lithium batteries before committing to any particular system / method of charging. I may look at it in the future, right now I am still up to my ears in NiMH charging principles and charging pattern design.
I think that that about wraps it up for now, the bike is back on charge following today's trip out and I have just spent about 3 hours writing this up. I'm off for a rest, a drink and little relaxation.
(The impossible we do at once, miracles take a little longer).
Very interesting work on the stock charger and thanks also for the info on the fans.
Could you possibly shed some light on the state-of-charge (SOC) calculation or display? Which unit generates the SOC (17 bar) display? Is it done by the charger, or by the motor controller, or by the instrument cluster? Have you come across some code in the charger for this calculation?
I suspect that the displayed sate-of-charge is calculated by dividing the Ah consumed or charged by the total capacity (between red light and full), but where is this done?
Excellent work there Laird. I know how many hours go into this sort of pic-code reverse engineering. You are to be congratulated on your dedication.
It would be interesting to see your analysis of the supplied code. (I assume you have worked out the algorithms, at least approximately, as well as which values are which). Obviously we don't really need this info for making the sort of changes you are describing, but there are many nerds who would find this interesting, and as you've owrked it all out you might as well spread the info (you might even get some help with further developments).
Presumably there are some checksum requirements too in order to make any changes and successfully upload the resulting file?
I'm not really familiar with the vectrix battery details, but do I understand that the batt can only be charged in series (well, in two unequally-sized parts IIRC?). i.e you do not have individual cell monitoring for temp or voltage? This is of course problematic when cells become imbalanced as you'd just like to charge the not-full ones whilst not heating the others with further charging. At least this method is possible with NiCd/MiMH charging (unlike lithium), but I reckon you really want individual cell temp monitoring for full failsafe charging.
BTW the power-in/power-out measurement scheme is called 'coulomb counting' in battery-charging circles (and it's famously unreliable, because even small errors tend to accumulate as you repeatedly charge/discharge). Nevertheless, with reasonable accuracy levels and some way of resetting 'full' from time to time, you can say whether a battery is 25%/50%/75% discharged which can be useful info. This is useful given the rather flat discharge curve of Nimh cells, and the problems of using the voltage across many cells to determine overall battery state. Here individual cell voltage measurement is very helpful.
That's probably enough general-purpose wittering from me - I think you know all this, and it doesn't help much for trying to work within the existing wiring and software constraints, which is the focus here.
Sakura s50 (Efun A)
A little Value Added Information.
The Vectrix Charging System – as designed
There are variations in the different software revisions, but some features are common to all. The script below describes, in general terms, the pattern of charging as adopted by Vectrix.
Constant Power mode – C.P.
In constant power mode the charger output current is determined by the battery voltage and the power output of the charger. The charger power output is set at 1500Watts and the battery voltage determines the current in accordance with I=P/V. Where I = current in amperes,, P=power in watts and v=battery voltage at the battery terminals.
The reasoning for using constant power is to facilitate the measurement of Power Input, to the battery, which in turn is used in comparison with the power out when the bike is in use, for the purposes of achieving the correct charge requirement in order to maintain a 'full' battery on re-charge without over or under charge taking place.
The Constant Power mode is 'terminated' by one of a number of the following causes:
The battery voltage reaches 152volts (C.P. 152)
The battery input power reaches a preset limit (32Ah)
The charge time reaches a preset limit (3.75hrs)
The battery temperature reaches the preset limit (50Degrees C)
It is not difficult to see why the VX1 suffered battery failures. All of the above limits have allowed the battery to exceed the point at which considerable heat is developed during the charging process. On each and every charge cycle the battery is heated and thereby pushed further and further into an unbalanced condition. As the battery heats up, different cells will heat at different start times (due to minor imbalances in charge held) the cells which heat earlier will reach higher temperatures and will therefore self discharge at a rate more rapid than the cooler cells they will also attain higher internal pressures and tend to heat adjacent cells again with the result of a higher self discharge. This exaggerates the imbalance and leads eventually to battery / cell failures.
The Tr mode
is not 'terminated'. It follows the cut-off in C.P.mode and serves only to cool the battery. Tr is a timed operation and runs for four cycles of 15 minutes each. In earlier software a small current from the charger was provided to power the fans without discharging the battery and the display showed this current and the timer countdown. Later software turned the display off whilst Tr was operating.
Tr is a transition mode from C.P. To C.C. Designed to allow the battery to 'cool off' following the heating produced during the C.P. Mode of charge. Allowing the battery to generate heat in the charge process is the first and biggest mistake that Vectrix made, and attempting to remove the heat during a 'cool off' period is akin to giving a drowned man a book on swimming lessons.
Constant Current mode – C.C.153
In constant current mode the charger output current is set at 3.0 Amperes and is intended to complete the charging process.
The Constant Current mode is 'terminated' by one of the following reasons:
The battery voltage reaches 151 to 154volts (C.C. 151 to 154)
The battery input power (C.C.mode) reaches a preset limit (6.0 Ah)
The charge time (C.C.mode) reaches a preset limit (2.5hrs)
The battery temperature reaches the preset limit (50Degrees C)
At 10% of Battery Capacity, 3.0 Amperes does not seem an unreasonable level of current. However, considering that the battery has already been overcharged by the C.P. Mode, it actually only serves to add to the damage. Again the 'Cut off limits' allow further damage to accumulate. Even 3.0 amperes, under the battery's present overcharged, overheated condition, can only result in further overheating and further damage.
The remaining modes are:-
C.C. To E.Q Cool off mode.- C.O. 000
Consists of a One hour cool off period which precedes the E.Q. mode if the battery temperature exceeds some 30 degrees C. and is followed by the:-
Equalisation mode – E.O. is brought into action only every 12 or so hours of discharge and is terminated by one of the following:
The battery voltage reaches 153volts (E.O.153)
The charge time (E.Q. mode) reaches a preset limit. (3.0hrs)
The battery temperature reaches the preset limit (50Degrees C)
The Equalisation mode is intended / designed to 'repair' the damage or, as we know it, the imbalance (the inequality of state of charge between the cells). What it actually does is to further add to the damage. It results in further charging the cells which are already full causing more heat damage (cell bulging resulting from excessive internal pressure and heat). Yes, any cells which were below capacity are now receiving the extra charge which they need to bring them up to 'full', but this is at the expense of damaging yet more cells and, due to the heating effects, causing further imbalance.
This script is a description of the Vectrix battery charging techniques as I understand them. Some of the figures are variable due to temperature compensations within the programme, others are variable with different software issues. The basic pattern of charging is a reasonably accurate report on what I have found to be the case.
My opinions are based on my own knowledge as an engineer and the information gleaned from many texts and text books on NiMH battery technology.
I make no apologies to anyone for anything other than for any typing errors which may have crept into this script.
I will repeat my regular assertions.
The imbalances are caused by an ill thought out charging and use process.
The process of charging can easily be improved, given the means to do so.
Cooling the batteries with the high power plenum fans is not the way to solve the problem. A cool regular breeze (to keep all cells at the same temperature) and a better charging profile is the only way to go.
Equalisation, (other than at very low rates as in the Freddy charger – Freddy does less damage but is not a solution to the problem), is not a practical option due to the potential for further heat damage.
Hopefully, you now have an understanding of the true cause of the Vectrix battery failures.
Those of you who have achieved higher mileages are lucky and probably live in cooler climates which helps to keep the average battery temperatures down, but it is luck and it is only a matter of time before imbalances begin to set in. Once the imbalances begin the Vectrix charger will do it's damage
Answers to Questions.
The state of charge display (0-17bars right hand display) is generated by the Instrument Control Module (I.C.M.) the information for this display comes from the charger and from the Motor Controller. I have taken little interest in this process as I am using a Modified Hex file generated from earlier charger software. The charger files are not compatible with the Motor controller files and I have 'lost' the 'used energy' input with the result that, whilst my 'fuel' display counts up with the charge it does not count down in use. Sorry!
Nice to have your input. I hope that the above script is the sort of thing that you were suggesting. I will send a personal message regarding other points.
Keep smiling folks,
(The impossible we do at once, miracles take a little longer).
Very impressive!! Thats quite alot of information to derive from only the hex code. Did your characterization of the Vectrix engineers also come from the hex code?
Yes, I think it needs to be remembered that the Vectrix engineers were being told to cut corners at several points along the way. Do it or loose your job sort of stuff. Particularly the battery management system could have been a lot better, but was practically omitted due to cost cutting. A much better system was initially planned.
I do imagine that the engineers were told to increase the range by overcharging and over-discharging the batteries on each cycle. And to recharge faster than what is good for the battery. All without regard for longevity of the battery - as long as it sells NOW!
If (or not) the engineers willingly agreed to have a black (and not heat-insulated) cover over the battery completely escapes my knowledge. I assume this was the brain child of a fashion designer - and thoroughly idiotic! A certain way to kill the batteries in Summer.
And lets not forget the elephant in the room: The batteries could be of poor quality altogether!
I was told by an ex-Vectrix engineer that they never even received ONE good battery for testing and development purposes. What I think s/he meant was they never got a complete 102s pack that did not have at least one under-performing cell in it. Packs like this should be matched and that brings the price up and requires high quality standards in the first place. The batteries might just not be of sufficiently high standards. It could also mean that the Vectrix Corp. did not have the organisational skill or resources to supply a good battery to the engineers - but I think what s/he meant was that the batteries were just not good enough.
I would assume that all and any engineers were bound and gagged by similar contracts to the ones that the dealers had to sign, which could make it difficult to give due credit for their work and help.
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Hi There XVectrix,
Nice of you to join in.
Who said 'only hex code'? The hex code is only part of the fun. An enormous amount of information can be gleaned from the behaviour of the bike and the charger. I have experienced in great detail the behaviour of two versions of the charger coding, I have experienced the behaviour of two faulty batteries and their treatment by the charger / software and I have experienced Vectrix engineers. Added to which, I am one of those people who will use every possible technique to gain the information necessary to get to the bottom of a problem. I have even had the 'lid' off a charger in my attempts to find out more about it. I am one of those dreadful engineers who will not be beaten whichever field of work I am in currently.
My characterisation of the Vectrix 'engineers' ( I am talking only of those who were in the design division and were responsible for the charger/motor controller electronics/programming/mechanical design) comes from my knowledge of what they have done in their programming of the charger, motor controller, etc. (as far as I can establish it) and from my own knowledge of both electronics, battery charging and problem solving.
You might note that far from being secretive about what I am doing, I am openly writing on this forum so that others may benefit. I have also offered to work with Vectrix to solve what really are their problems. Can I do more? or are you just curious about something? Whichever, If you can help out in any way, information, circuit diagrams, software old and new, then I would love to hear from you, via a personal message perhaps?
In the mean time I shall continue to do what I can to improve my Vectrix and write up anything of interest to others as I go along. I am retired, I have the time and I don't need the money but I do have the skill. During my working days, I have occasionally had to explain to my superiors that I will work only to the best of my ability regardless of what they would prefer. I would rather not work at all than work for someone who doesn't understand the job I do and yet has the effrontery to tell me how to do it. I will not ask which side of the fence you are on.
My sole aim is to own an electric vehicle which is both practical and efficient and also does, reliably, what it is supposed to do.
Thanks for the input/interest
Best wishes to you
to bring it back to topic: I did some research not for the 30AH version of the GP batteries, but for the 78 AH version.
Mainly I researched for the possibility and danger of parellel charging two modules with several cells. Two of the sorces
[Akku types] and [Tech. specs NiMH from GP] did warn not to charge this chemistry parallel AND they warned not
to charge below 0°C/32°F. In this case there is a danger for fast and heavy preasure-rise in the cell opening the vent and
weakning the battery.
Amazing info, thanks The Laird!
My bike has just over 2600 miles and I have been experiencing battery issues for some time. I spoke with Matt Hair back in November, a tech at V and very nice guy, and he thought it was due to not riding the bike regularly and the self discharge. The bike sits during the week and I ride it on the weekends. I find it frustrating that the bike cannot deal with sitting for a week or two and cannot seem to be able to adjust. I have been around EVs for years and I find the charging parameters you described to be idiotic. I always wondered why they used these charging algorithms when it obviously caused heating of the battery. Why not charge it slower at the end?
Matt said when he was down this way he would take a look at my bike and run some diagnostics to check the battery status. Unfortunately its been 2 months and I have not heard from him.
I don't know that my battery is damaged beyond hope but I believe at a minimum it is seriously out of balance as I get the red light regularly now even on short rides ( 10 - 20 miles of conservative riding) I have been looking for a way to "gently" and non destructively balance the pack. I would like to try your charging hex but I live in Houston and we have extended periods of 3 - 4 months where the ambient temp never drops below 25C - 77F. I am also running one of the newer firmwares.
From what you said if you could keep the batteries more balanced through a lower final charge rate at the last 1/3 of the charge that does not heat the batteries then it would be easier to charge them reliablely at 11 amps through the first 2/3 or 70% soc( the point where it seems heating becomes more pronounced). I am not an engineer so I rely on those of you that are. One thing you did not mention is whether the higher rate 11 amps versus your lower rate of 6 - 8 would cause greater cell differentials due to varying internal resistance of the batteries, whether due to age, damage, construction etc. Is the added 3 - 6 amps enough to cause differing resistance and cell temp variations? Of course the universal constant for charging batteries is slower is better. But I live in a rural area and town is 10 miles so I constantly take advantage of opportunity charging when I am out so the higher 11 amp rate during a lower SOC is very attractive to me.
But it's no good to you if the battery is dead so a healthy battery is ultimately whats important! I would take an 8 hr charge time if the batteries stayed healthy with a good usable capacity for 5+ years of fun.
Thanks for all the valuable data!
Hello Todd (and everyone else too),
I am currently testing the 'new/re-arranged' Software. In fact, a second Vectrix has now been 'fitted' with the latest version and so far all is going well.
It has been necessary to go back to the earlier Motor Controller software due to compatibility issues. None of these minor details is of any great concern. Battery charging is now taking place with virtually no heating of the battery (I don't consider a 2 degree C rise in temperature over the whole recharge cycle as 'heating').
I am making some attempts to speed up the recharge times and it may be feasible to reduce the times marginally, so if you are in a permanent hurry, it may be possible to accommodate your needs.
If testing over the next two weeks continues to exceed expectations as it is doing at the moment, Then I shall be in a position to 'take orders' from those of you who are interested ( I am assuming that some of you might be interested - perhaps I shouldn't assume such things). By 'taking orders' what I mean is that the charger software will have to be varied slightly according to the ambient temperature of the location in which the bike is used. 'One size fits all' never does as far as I am concerned, so there will have to be (minor) variations.
My latest notion / intention is to completely change / re-arrange the. so called, equalisation process. If my latest design works as intended, then, when coupled to the charging improvements, battery life in the old Vectrix may at last achieve the figures which Vectrix envisaged but so far have failed to achieve. I also expect an increase in range (5% to 20%), I will explain how, when I report on this one later. Results on this one will be known within a month, so keep your fingers crossed for me.
For anyone out there with a battery which is beginning to show signs of failure, I suggest that you don't take it down to the 'red light', don't do any more 'deep discharges' and don't allow the battery to heat up when charging. If charging causes a temperature rise of more than 2 or 3 degrees, then switch off the charger and allow the battery to cool before continuing the charge. If the temperature is over 25 degrees, then you can use the 'charge delay timer to help with cooling- the left brake /switch off technique.
Some self protection small print:-
Once again, I remind you that I am offering my opinions and giving you information. What YOU do is entirely YOUR decision. I can accept no responsibility if anything goes wrong.
Have fun folks and keep smiling,
(The impossible we do at once. Miracles take a little longer)
I don't know if this is a dumb question, but I'll ask it anyway. I have a time clock that can have multiple times in a 24 hour period. Would it help if charging was done in, say, 15 min increments with an hour or so rest in between? I'm not sure what happens if the V is turned off during the charge cycle and then turned on again.
It is not a 'dumb question'. However, it wont work by itself as a cure for the problems caused by the Vectrix charging routines.
In fact, because the fans would go off every time the charger goes off, you would actually get a heat build up between charges. Basically, this is not a good idea and I strongly discourage you from trying it.
Keep working on it and keep smiling,
(The impossible we do at once. Miracles take a little longer)
You are bringing more hope to our old vx1 than the vectrix brand.
Go the Laird Go!
It does seem that the whole problem is that the charger is being used as a sort of makeshift BMS. Wouldn't the solution be to instal a BMS and let the charger go back to being a charger?
Perhaps completely replacing the V charger with another good quality one?
Blogging my Zero DS from day one http://zerods.blogspot.com/
I am definitely interested in modifying the charging process to lengthen the life of the battery. I don't have a canbus adaptor or a PC laptop, but my son is a computer programmer -- I'm sure I could show him the hex code and ask him to make the changes for me.
I look forward to having a healthier EV, thanks for your work and for sharing with us.
certainly, Gasdive, you're right. Any multicell battery needs BMS. That's the solution... but that's the real problem: Where can we buy a NIMH BMS? I've never spoted one single device in the WWW market...
i really want to thank you for all the good work that you are doing. I've been closely following this thread and others similar and I beleive it can only improve our units and make the the batteries last longer.
I for one would be interested in trying your new software - bearing in mind in the South of France in summer we have maximum temperature of about 35 degrees C. In the winter it gets down to about 10 degrees C during the day - colder at night although this year it has been much colder - happily now it has warmed up a bit.
I'm curious to know if you have had any contact from Vectrix commenting/helping you with your work.
I'm sure I'm not alone in thanking you for what you are doing.
All the best
Thanks for the response and the update Laird.
I would like to give this a try when you are ready. It is currently winter here so temps are in the 10C - 20C range and I could work with that for several months.
What would I need in order to revert my V to the older firmwares compatible with your mod? I have a laptop and it sounds like I need an adapter?
It would be comical if it were not so serious that the tech from V told me to deliberately run the bike down to the red light, recharge and run down again. And that running it down regularly is an important step in keeping the battery healthy and it sync. I know they are trying to help but it sounds as if they are totally unaware of the effect their charging algorithms are having on the battery health. :(
One or two of you are showing interest in the software changes which I am working on and there are a number of queries which I need to address.
Todd has questioned the power output of the charger and it's potential to do damage. It appears that it is not the level of current alone which creates the problem (of heating) it is the high current charging which occurs when the battery has reached/passed the 70%/80% of full charge. In all batteries there is a point at which the battery can no longer accept a high current charge. The Vectrix software continues to charge at high current long after this point is passed, hence the damage which is caused by overheating the battery. I am hoping to safely increase the initial charging current that I am using (6Amps), but more testing will need to be done before further changes can be made.
In any event, the 6 amps charge will attain 80% full from empty in four hours. the Vectrix rate of 10/11 amps takes just under two and a half hours to do the same. Is the hours and a half saving in time worth a damaged battery?
Gasdive suggests a B.M.S. would solve the problem. There does not appear to be a commercially available B.M.S. that could be retro-fitted to the Vectrix. Mik is working on his own B.M.S. in an attempt to solve that problem. The Vectrix B.M.S. simply doesn't work. YES, there is one and YES it is fitted to your Vectrix but it does not work.
Jonathanm has asked if Vectrix have made any contact with me. Answer is NO. I have even offered to work with them for no pay. My only request is that they allow me access to the software collection and circuitry. So far, NO RESPONSE.
One or two of you have offered to test the 'adapted'/'altered' software. I want to write one last post, which will follow this one very soon. In it I shall outline the principles of operation, and any potential problem areas. I shall also indicate that the results of using this adapted software will be the users absolute responsibility. If you agree to this then I will supply copies of the software as altered for you to try out.
I will leave it there for now and press on with the promised 'last post' on this topic.
The Adapted Vectrix Software
I have now completed the preliminary testing of the 'adapted' charger software. The adaptations have all been proved to work as intended and no problems have been encountered.
The software which I have adapted is the 2012 version charger software and it does require being used with the MC1014 motor controller software.
This software combination does not have the 'left brake/kill switch' facility to provide the voltage and temperature readouts. Nor does it have the 'pre charge cooling delays' (although I suggest that they are no longer necessary)
The cut off battery voltage, which operates the 'red light', is at a lower level than in the later software. There is a potential to damage the battery if it is run down to the 'red light' and the battery is in a seriously imbalanced condition. (This is a 'motor controller software issue which I am trying to get control of, so far without success).
The battery can now be charged with a minimum of heating, thereby reducing the potential for imbalance to occur
The equalisation charge has been altered and will no longer allow excessive overcharging to occur.
The plenum fans will operate at all times when the Vectrix is in use, riding and charging. The fans will 'run on' following use for some ten / twenty minutes. This results in the cells within the battery being maintained at a more even temperature throughout their use, again reducing the opportunity for imbalances to occur.
'Safeguards' in the software have been altered to reduce battery damage. Temperature limits have been lowered. Maximum Voltages lowered. Maximum current levels have been lowered. Other limits have also been lowered in order to effect a safer charging process.
This has all been done with the intention of reducing cell imbalances without the need for complex (and as yet unavailable) Battery Management Systems.
As I have already said, work on the charger software is at a stage where a viable charging routine exists.
The next step is already in hand and that is to devise a system of equalisation which will take care of any imbalances which do occur (or have already occurred prior to using the new charger routines) without creating further damage to the 'good' cells.
The principles of a new equalisation method are already undergoing tests and results should become available in the next week or two. If anything this will prove to be the more difficult part of the process to implement, but more of that later.
Finally, I would like to re-arrange the motor controller software. Without a doubt, problems are being created by the regeneration system and also by the excess currents which can be unwittingly drawn from the battery. I would like to produce software variations which will give the owner/rider the choice of a longer battery life with a more sedate ride or a shorter life with excitement thrown in. Again, more of that later.
If anyone out there wishes to have a copy of the 'altered' software which I have described then send me a 'personal message' with your e-mail address and I will forward to you copies of the necessary files. Tell me also the local ambient temperature and I will match the software to your locallity.
You will need: A Computer and Canbus adapter and ideally, you will already have the ability
to install this type of software.
I will provide the instructions and procedures and copies of the altered hex files.
The 'small print'
If you send me your e-mail, then you are agreeing that you as the user, are taking total responsibility for your actions regarding the use or otherwise of these hex files/software. You are also agreeing that I will not be liable for any consequences whatsoever which may result from your use of this information and /or software and /or hex files.
Finally, I would like to remind you that my scripts have been a record of my attempts to reduce damage to the battery on my Vectrix scooter. I have told you what I am doing and why I am doing it. I am not advising you to do anything, instead I am offering you the opportunity to imitate my work if you chose to do so.
Keep smiling folks,
(The impossible we do at once, miracles take a little longer).
Just one silly question.
If you modify the 300x version of the charger:
1- you'll have the 'left brake/kill switch' facility
2- you'll have the 'pre charge cooling delays'
3- will work with latest hex file of motorcontroller - higher voltage cutoff. No need to modify it.
is it possible?
Once again very thorough info Laird.
When discussing equalizing are you thinking a specific equalization charge to "whip" the batteries into shape or equalization slowly over a number of cycles? My understanding of NiMH batteries is when charged at a higher rate once they reach there full capacity they heat up quickly, and hence the damage, However I have read( on smaller NiMH ) that they can be charged at a low rate, C/10, for a long period without damage. It seems that C/10 still generates significant heat with the V. If you are currently charging at 1 - 1.5 is that what you are thinking of using?.
Once again ideally and from a practical standpoint if you could get 80% charge as quickly as is safe, then the last 20% could take another 4 - 6 hours without a problem. We are not trying to create marketing hype so an 8 hr charge time to 100% either during the work day or at night would work for most. And opportunity charging to 80% safely without heating would make the bike and entirely different ride.
What about the calibration charge the V does after 12(?) hrs of use. Is that implemented in the firmware you are using. If so can the final stage be adjusted down to 1 - 1.5 amps?
Where can I get an appropriate canbus adapter?
Hi Todd, many people use the Peak CAN Adapter available optoisolated for more safety but more expensive or normal. Mine is optoisolated
but works sometimes instable which is maybe an effect of the USB 1.0 of my old Laptop? Definitely problems occure when I used an USB-extensioncord, so I plug adapter and laptop directly now. My adapter did come with a violet CAN-conectionwire too, but I don´t know if it is needed or if the adapter can be directly used with the scooter (I use the violet wire).