Battery Performance

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Wotnopetrol
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Battery Performance

Being a techie and a bit of an anorak (Item of clothing usually worn by train spotters in the UK as a sort of badge of their obsessive behaviour :-)) I have been keeping a sort of log to track the hopefully increasing battery capacity therefore range of my Vectrix.

I have noticed a couple of things, that it seems that the battery capacity is increasing gradually by doing only PARTIAL discharge/recharges i.e. doing the same route of 25 miles a day then a full recharge.

I know the Range'o'meter is a bit all over the place, but there are more fuel gauge bars left at the end of the day now then when I started my Vectrix commuting and the time taken to recharge is getting less and less. The Range'O'meter is also higher at the end of each charge too.

I hope this apparent increase in battery capacity is actually what's happening and not that I'm learning to eek out the amps better by riding with a less heavy hand.

Vectrix-NH
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Re: Battery Performance

I have found the same with a 20 mile commut each way , and charging at each end .
It is now comsitant enuf I can tell when my tire inflation is down just a few lb

Happy riding < Herb

AndY1
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Re: Battery Performance

I think that also the broken-in gearbox adds to the added mileage.

mcstar
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Re: Battery Performance

I'm not familiar with your particular setup, however that sounds like what happens whenever some of the cells in a pack are out of balance. Each time you do a partial discharge is another chance for them equalize out a bit and take more charge, thereby becoming closer to equally balanced.

Mik
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Re: Battery Performance

I'm not familiar with your particular setup, however that sounds like what happens whenever some of the cells in a pack are out of balance. Each time you do a partial discharge is another chance for them equalize out a bit and take more charge, thereby becoming closer to equally balanced.

Exactly!
That is why I recommend shallow discharges to start with, see: http://visforvoltage.org/forum/4843-i-still-don039t-have-my-vectrix-what-do#comment-29020

It can't do any damage.

The proof is however in the pudding, and only real range testing will be able to show you if the range is actually better or if the electronics just "think" there is more power in the battery.

This information may be used entirely at your own risk.

There is always a way if there is no other way!

Wotnopetrol
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Re: Battery Performance

Exactly!
That is why I recommend shallow discharges to start with, see: http://visforvoltage.org/forum/4843-i-still-don039t-have-my-vectrix-what-do#comment-29020

It can't do any damage.

The proof is however in the pudding, and only real range testing will be able to show you if the range is actually better or if the electronics just "think" there is more power in the battery.

Tonight I had 9 bars left before the recharge, having gone up from 7 left for the identical commute at the beginning of the week.

The charge time has gone down from 4:03 to 3:45 and the Range'ometer after recharging has gone up from 43 to 86 miles.

At the weekend I'll do a real world range test, if I have time, to see if I get more than the 49.3 miles maximum achieved so far.

It seems like the batteries may be settling in and balancing nicely.

This may mean this is the way to condition the batteries.

Simon

Simon

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Re: Battery Performance

Interesting. That info (Mik's and Wotnopetrol's) is very useful for me, since I haven't done any driving or charging yet. I'm still waiting for the documents to get the licence plates.

So Mik, if I read you correctly, your suggestion is to do 2-3 full charges with only 2/3 of the battery discharges before starting deep-discharge cycles - to balance the battery cells?
Would 2-3 trips be enough in your opinion to balance cells before starting deep-discharge cycles?

Mik
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Re: Battery Performance

Interesting. That info (Mik's and Wotnopetrol's) is very useful for me, since I haven't done any driving or charging yet. I'm still waiting for the documents to get the licence plates.

So Mik, if I read you correctly, your suggestion is to do 2-3 full charges with only 2/3 of the battery discharges before starting deep-discharge cycles - to balance the battery cells?
Would 2-3 trips be enough in your opinion to balance cells before starting deep-discharge cycles?

No, not quite.

I meant to say: Discharge the smallest amount out of the battery that lets the charger start in CP mode.

If the battery is still too full, or if the machine "thinks" it is still full, then it will only do a very short trickle charge of 3min or so. That would not significantly reduce imbalance between cells.

The battery might be quite empty and unbalanced due to months of inactivity and slightly different spontaneous discharge rates between cells.

But to the best of my knowledge the electronics do not take self discharge into account for the state of charge estimation.

Vectrix techs might have conditioned and charged your battery recently, or it might have been neglected for a long time. No way of knowing for me.

In my experience the charger will not do a full CP, tr, CC, EC cycle unless at least 1 or 2 if the 17 bars have been drained.

So if you just drain the battery a little bit, but not too little, then you will in effect trickle charge it when you plug it in. If the temperature does not rise during this, then the trickle charge is being absorbed and the battery is not too full.

But by all means, try to get some advice out of Vectrix on how to best treat your battery. Maybe they are more willing and/or able to answer this question by now.

I'll quote myself here, forgive me, please:

If I had a new Vectrix I would NOT try to do deep discharges early on.

I would ride it a little bit at a time, only until the battery display is down to 15/17th. (About 5 to 10km.)

That would allow it to go into CP charging mode for a short time when plugged in, followed by an hour or so of CC charging and 59min of EC charging.

That would allow any low-charge cells to gradually catch up, whilst the fuller ones would heat up only a little bit.

I'd do that a few times and gradually increase the range. Each time I'd recharge fully including the trickle charging modes as above.

I would try to reach a power point (and use it!) at the same moment that a slight performance reduction is first noticeable (stay very close to home in other words).

Once the distance at which a slight performance reduction is noticeable does not increase any longer between recharges, I would start the first "deep discharge cycle".

This is all geared towards equalising the 102 NiMH cells' charge state, before risking reverse charging of a cell in the string that might have self-discharged quicker than the others for some reason.

This information may be used entirely at your own risk.

There is always a way if there is no other way!

marsupi
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Re: Battery Performance

Hi all,
new Vectrix owner here! Just received mine yesterday.
I have been following with interest your different discussions over battery charging and I thought this GP document might be of interest to some of you if you don't have it already.
http://www.gpbatteries.com/html/pdf/NiMH_technical.pdf

As a side note:
I just powered up mine upon arrival and I also get the flashing Battery and HighTemp telltale after the initialization sequence while the battery level show full 17 bars and 126km range on the display. I have yet to do a first charge...hopefully that will reset the range and battery level.
I just had time to drive it for 50m to park. I will install a voltage and temp meter before the first charge.

Also of interest,the patent issue to Vectrix on the equalization circuit:

http://www.patentstorm.us/patents/5965996.html

Regarding the topic at hand, I will reiterate some aspects that have been mentioned in previous post:
*to prevent the risk of cell reversal:
-at low current: cell voltage limit is 1V (for example to do a deep discharge cycle)
-at high current: 1.22V per cell max (under load nominal pack voltage 125V is the limit)

(firmware upgrade suggestion: it would be nice to be able to display voltage instead of range under load to prevent cell reversal)

Since it's not clear in what state the batteries are when the scoot is delivered, I would agree with Mik about doing low discharge at first to force the charger into CC and EC to equalize the batteries. After a few low charge/discharge cycles, a deep discharge can be done. I would suggest dropping the last bit of the pack voltage (to 1V cell) under no load (scooter on a stand) at the very end so you are less likely to get cell reversal and also doing this after the batteries have rested and reached room temp. Then do a full charge.

07 Vectrix, Vego 600 mod.48V 800W, Arcade Alu E-Cycle 24VSachs Hub

Wotnopetrol
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Re: Battery Performance

Hi all,
new Vectrix owner here! Just received mine yesterday.
I have been following with interest your different discussions over battery charging and I thought this GP document might be of interest to some of you if you don't have it already.
http://www.gpbatteries.com/html/pdf/NiMH_technical.pdf

As a side note:
I just powered up mine upon arrival and I also get the flashing Battery and HighTemp telltale after the initialization sequence while the battery level show full 17 bars and 126km range on the display. I have yet to do a first charge...hopefully that will reset the range and battery level.
I just had time to drive it for 50m to park. I will install a voltage and temp meter before the first charge.

Also of interest,the patent issue to Vectrix on the equalization circuit:

http://www.patentstorm.us/patents/5965996.html

Regarding the topic at hand, I will reiterate some aspects that have been mentioned in previous post:
*to prevent the risk of cell reversal:
-at low current: cell voltage limit is 1V (for example to do a deep discharge cycle)
-at high current: 1.22V per cell max (under load nominal pack voltage 125V is the limit)

(firmware upgrade suggestion: it would be nice to be able to display voltage instead of range under load to prevent cell reversal)

Since it's not clear in what state the batteries are when the scoot is delivered, I would agree with Mik about doing low discharge at first to force the charger into CC and EC to equalize the batteries. After a few low charge/discharge cycles, a deep discharge can be done. I would suggest dropping the last bit of the pack voltage (to 1V cell) under no load (scooter on a stand) at the very end so you are less likely to get cell reversal and also doing this after the batteries have rested and reached room temp. Then do a full charge.

Welcome Marsupi to Vectrix ownership!

Well I did it all wrong by doing a deep discharge after delivery, closely followed by 3 more.

Now I'm doing my normal daily commute so I'm only getting down to a theoretical half empty situation before recharging.

I expected after the 4 full discharge/recharges to start to see an improvement to range but it wasn't happening. The range does now however seem to be increasing (in theory) suggested by:

The wildly varying Range'ometer.
The 17/17 bars, i.e. having progressively more and more bars left after my daily commute.
And the reducing required charging time for the same daily journey.

I think this last point maybe the best indicator, but a real world range test is of course the only way to prove my battery pack's (hopefully) increasing capacity.

Of course it could all mean that everything is bedding in and the bike is rolling more easily after 350 miles.

I know no one believes it still, but that demo bike at my dealer that's done 18,000 miles is reported to have done 80 miles on a single charge!

Is there anyone who has done anywhere near that mileage yet? We may have some pleasant surprises to come as our bikes batteries, drive train etc. get nicely worn in.

I won't hold my breath, but it would be very nice if it happens this way. :-)

Simon

Simon

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Re: Battery Performance

The wildly varying Range'ometer.

The range'ometer is base on the battery and the last couple of min. you have driven .
So if you use some regen brake it will read more then it should ( with half my bars I have had it read 60 mile left a long down hill with a lot of regn brake ) and if you just zip full throttle in that time it will read very few miles
( some times it reads as few as 18 miles with a near full battery ).

Not that great but better then the first software I had . the range'ometer was just like the bars.
It started at 55 mile and just went down stead about 2 miles for ever one I did.

After having my Vectrix a full year . I do not look at any of that much . I have learn how many mile I can go in my area . when the bar Graph is at about 5 bar I can not go 65 mph but can go about 5 to 10 more mile at a redused speed
witch I determane by how far I have to reach my next charge .

Happy Riding , Herb

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Re: Battery Performance

The GP document is VERY informative. Thank you!

Since I also have an undriven Vectrix, I will do a few(2-3) shallow discharges first, followed by a full charge and only do 5 deep-discharges after that.

Mik
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Re: Battery Performance

I just powered up mine upon arrival and I also get the flashing Battery and HighTemp telltale after the initialization sequence while the battery level show full 17 bars and 126km range on the display. I have yet to do a first charge...hopefully that will reset the range and battery level.

Welcome!

Thank you for the links.

There might be something wrong if the battery and high temp telltale is on.

The only condition (that I can think of) in which this is not a "fault as such" would be if the Vectrix had been (over)charged before delivery to you and the battery is still hot.
It can take days to cool down completely, but it should really be cool enough after a few hours to not show a warning telltale. And usually the fans would have run to cool the battery to an acceptable level.

I would assume there is something wrong and contact Vectrix immediately if the warning persists after a reboot.

You could also plug it in and note the battery temperature and voltage after one minute of charging, or turn the key to ON for a minute before plugging in, that will give you an immediate temp and voltage reading.

The temp reading might however be incorrect, the older style temp sensors are prone to failure.

If the battery is really hot, then the battery cooling fans would come on when you turn the bike on and the air expelled in front of the rear wheel will be warmer than ambient temperature (unless it is a stinking' hot day!)
Do not confuse battery cooling fans with MC cooling fan, it has a similar location, but MC fan runs when GO is displayed and has variable speed, and is much more noisy. Sometimes it continues to run after a hard ride for a few minutes until the MC has cooled down.

This information may be used entirely at your own risk.

There is always a way if there is no other way!

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Re: Battery Performance

Mik, do you think 3 shallow discharges would be enough to balance the batteries prior to first deep discharge?

Mik
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Re: Battery Performance

Mik, do you think 3 shallow discharges would be enough to balance the batteries prior to first deep discharge?

As a rough estimate, assuming the worst case scenario: Some cells empty, some cells full.

To put 30Ah into the empty cells via CC and EC parts of charging, you need about 10hrs of CC charging, because in CC mode about 3A = C/10 go into the battery.
In EC mode it is less.

You might also find that the BMS just does not go to CC and EC if you do shallow discharges and recharges at first.

Have a read of the patent linked to above and see if you can make sense of it, I'm digesting and cross referencing it at the moment with the hardware in front of me.

So far I believe the Vectrix BMS does a lot less than what is theoretically covered under the patent, but it might actually be shunting energy between 2 batteries of 27 cells each and one battery of 48 cells. That is only possible if the current shunts through the same cables which are used to measure the voltage, because there are only three cables going to the cells in addition to the main pos and neg cables at the ends of the string.
One cable goes to cell 27, one goes to cell 75, one (negative/ground for the two others??) goes to cell 1 (most negative cell in the series).
These cables are thin and could not be rated for more than a few amps, maybe 2 to 5 amps. But that might be all that is needed to shunt all current to a part of the string that has a lower voltage during CC charging.

The long and the short of it: I do not know!

But the BMS current shunting can only happen during slow charging.

If the BMS works well, you will help it by giving it more time in slow charging mode.

If the BMS does not work well, you will balance the cells by giving them more time in slow charging mode.

Same thing. Just a question of how often you want to repeat it.

3 to 5 times is probably sufficient in almost all circumstances.

See if you can figure it out, here are some pictures to help:

//i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20Rework/th_BatterySchematic14.jpg)
//i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20Rework/th_DSC05295cropped.jpg)
//i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20Rework/th_DSC05123.jpg)
//i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20Rework/th_DSC05125.jpg)
//i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20Rework/th_DSC05117.jpg)

This information may be used entirely at your own risk.

There is always a way if there is no other way!

AndY1
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Re: Battery Performance

I'm doing my first charge. It has come to EC and the clock is counting down 60:00. What does it mean? Do I have to wait for 60 minutes or is this the end of charge and I can drive? Why is it counting down from 60 minutes?

Please for quick reply as I want to drive this baby today :-)

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Re: Battery Performance

I'm doing my first charge. It has come to EC and the clock is counting down 60:00. What does it mean? Do I have to wait for 60 minutes or is this the end of charge and I can drive? Why is it counting down from 60 minutes?

Please for quick reply as I want to drive this baby today :-)

You've probably figured it out by now as this post is quite late, but the count down is just that, a countdown to ready to GO!!!!!

Enjoy! :-)

Simon

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Re: Battery Performance

I'm back from my first drive!!!! :D

First thing I did was to check the tire pressure. It was 3.0 Bar in both tires. I deflated them to a 2.2 and 2.8.

40km done, 8 bars left and the bike isn't even broken-in yet. I kept the speed <= 70km/h (for battery breaking-in). Tomorrow I will do a full recharge and drive it until the deep-discharge.

Other drivers were staring at me, cars driving by me - watching me, on the traffic lights I saw drivers showing their passengers in my direction :-)

Amazing experience. I love the bike.

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Re: Battery Performance

You can unplug and ride anytime you want to, regardless of charge state, but the charger will shut down and all guages will turn off when the charge is complete.

The timer goes up and down, depending on the charge stage, and the speedo shows current draw or something, and there's a temp indicator on the left, but all that stuff just means it's working, doing what it was designed to do. Understanding all that stuff may lead to anylizing all that stuff, and perhaps lessen the enjoyment factor. If you want to be kind to the bike, just give a little cool down break before charging, and the same between charging and riding when you can.

I set my charge point at the house up with a timer, set to come on late at night, and shut down early in the morning, so the bike has a few hours to cool down after riding and a few hours to cool in the morning before riding again.

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Re: Battery Performance

I set my charge point at the house up with a timer, set to come on late at night, and shut down early in the morning, so the bike has a few hours to cool down after riding and a few hours to cool in the morning before riding again.

Trying not to overanalyse this temperature thing, everything you say makes good sense.

The timer sounds a good idea.

I know operating and ambient temperature is very important with all kinds of battery chemistries. On a climb up Kilimanjaro once, I did my research beforehand and my head torch was the only one out of our group working at the -20c temperatures we experienced because I used Lithium double A cells.

Lead acid batteries display poor performance starting cars in the winter time, even in our relatively mild winters in the south of England.

What I'm wondering is if our Vectrix battery pack is affected by cold temperatures much, and if a timer controlled warming up charge prior to my winter early morning commute to work would be beneficial to it, as opposed to letting it reach 0c or less, and then having it fail to give the range and performance I am enjoying right now.

Simon

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Re: Battery Performance

So far I believe the Vectrix BMS does a lot less than what is theoretically covered under the patent, but it might actually be shunting energy between 2 batteries of 27 cells each and one battery of 48 cells.

I think your right about the BMS, it's only that a Battery Monitoring System, from the looks of it there is no balancing circuit. Looks like there is only a PIC18F877 microcontroller and a MCP2515 CAN chip.

Actually the balancing circuit is not necessary for this kind of chemistry if the battery is used properly (respect temp and don't overdischarge) and if charger does it's job and completes the EC.

My previous experience with Ovonics NimH on EV's has proven to be good over time even with no balancing circuit, but it does require a few consecutive full discharge/charge cycles once in a while as preventive maintenance to balance the pack.
High temp, overcharge and cell reversal(overdischarge) are the main battery killers
In general 3 to 5 consecutive full charge/discharge cycles should be enough to balance the pack. If you have a very unbalanced pack more may be required, but unless you check each cell it's hard to tell.

07 Vectrix, Vego 600 mod.48V 800W, Arcade Alu E-Cycle 24VSachs Hub

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Re: Battery Performance

There might be something wrong if the battery and high temp telltale is on.


I would assume there is something wrong and contact Vectrix immediately if the warning persists after a reboot.

The temp reading might however be incorrect, the older style temp sensors are prone to failure.

I think I'm up for a little trip to the dealer, it's been pretty cold in Paris lately, way below the 21 degree it's showing and it's stuck at that temp from what I can see. The different fans however seem to work just fine during charge and in GO. I'm still waiting for the COC from Vectrix so I can't really drive around anyway.

07 Vectrix, Vego 600 mod.48V 800W, Arcade Alu E-Cycle 24VSachs Hub

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Re: Battery Performance

High temp, overcharge and cell reversal(overdischarge) are the main battery killers

What do you consider high temperature for battery? Over 50'C?

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Re: Battery Performance

There might be something wrong if the battery and high temp telltale is on.


I would assume there is something wrong and contact Vectrix immediately if the warning persists after a reboot.

The temp reading might however be incorrect, the older style temp sensors are prone to failure.

I think I'm up for a little trip to the dealer, it's been pretty cold in Paris lately, way below the 21 degree it's showing and it's stuck at that temp from what I can see. The different fans however seem to work just fine during charge and in GO. I'm still waiting for the COC from Vectrix so I can't really drive around anyway.

I did a first full charge today, but when I connected the 220V, for a minute, the battery temperature also showed 21'C. Then it went down to the real temperature of 14'C. You have to wait a bit.

marsupi
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Re: Battery Performance

What I'm wondering is if our Vectrix battery pack is affected by cold temperatures much, and if a timer controlled warming up charge prior to my winter early morning commute to work would be beneficial to it, as opposed to letting it reach 0c or less, and then having it fail to give the range and performance I am enjoying right now.

low temperature will definitely affect your range. your idea will help keep the pack at optimum temp. for example you can plan it so that you reach the end of charge about an hour or so before you leave, maybe less if it's really cold.

07 Vectrix, Vego 600 mod.48V 800W, Arcade Alu E-Cycle 24VSachs Hub

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Re: Battery Performance

[
I think I'm up for a little trip to the dealer, it's been pretty cold in Paris lately, way below the 21 degree it's showing and it's stuck at that temp from what I can see. The different fans however seem to work just fine during charge and in GO. I'm still waiting for the COC from Vectrix so I can't really drive around anyway.

Sorry, I was not very clear when I wrote:

You could also plug it in and note the battery temperature and voltage after one minute of charging, or turn the key to ON for a minute before plugging in, that will give you an immediate temp and voltage reading.

I should have added: If you do not wait a minute then you always get 21dC as temperature display.
That might however be the right temperature, it is surprising how long it takes for the batteries to cool down.
It takes DAYS, not hours, if the fans are not running.
Hard to believe until you check it out yourself.

We are talking about 90kg of warm metal and chemicals, wrapped in several layers of insulating plastic.

This information may be used entirely at your own risk.

There is always a way if there is no other way!

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Re: Battery Performance

We are talking about 90kg of warm metal and chemicals, wrapped in several layers of insulating plastic.

Such a shame some of that heat can't be channeled to the handlebar grips for winter riding. I have that on both my other bikes and it's glorious. In fact one of them even has a heated seat. Now that's luxury.

Simon

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Re: Battery Performance

It takes DAYS, not hours, if the fans are not running.
Hard to believe until you check it out yourself.

Thanks for the precision and correction, Mik is right about the temperature taking days if fans are off, hence the benefit of the ABCool setup.
Mik do you know if the fans turn on automatically if the batteries get hot while the scoot is off or unplugged?

07 Vectrix, Vego 600 mod.48V 800W, Arcade Alu E-Cycle 24VSachs Hub

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Re: Battery Performance
It takes DAYS, not hours, if the fans are not running.
Hard to believe until you check it out yourself.

Thanks for the precision and correction, Mik is right about the temperature taking days if fans are off, hence the benefit of the ABCool setup.
Mik do you know if the fans turn on automatically if the batteries get hot while the scoot is off or unplugged?

Yes, that happens sometimes when the battery temperature is high when the fans are running or whilst forced airflow from riding cools them a little bit. The temp sensors are affected by both the cell temperature and the air temperature in the battery compartment.

After stopping or after charging the air temperature will rise due to lack of air flow.

If one of the 12 temperature sensors was already close to the trigger temperature of 45degC (I think) with air flow, then it will soon trigger the fans to start.

I've seen (or rather heard) it happen after riding and after charging on hot days.

First it's all quiet, then suddenly the battery cooling fans switch on.

I hope it will never be hot enough to gradually heat the batteries to over 45degC where the Vectrix is parked. If that happened, then the battery would actually be further heated by the ??50degC air flow caused by the fans. They would never stop running until the ambient temperature drops enough to cool the batteries to below 46degC again.

4A x 12V = 48W power consumption for the fans, plus DC/DC converter inefficiencies.

3.7kWh / 48W = 77hrs to totally drain the battery (if it is fully meeting advertised specs and not considering spontaneous self discharge which would be very high at that temperature)

This information may be used entirely at your own risk.

There is always a way if there is no other way!

AndY1
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Re: Battery Performance

I did a first deep-discharge today.

I did a full charge in the morning, I've driven 70km (at <= 70km/h) without loosing any power. At 70km I had 1/18 bars left and started loosing power, but very gradually. I drove on a very flat terrain around my home for several more kilometers until it came to a stop and I turned it off. Then I waited for a few (2-3) minutes, turned it on. It regained some power and drove it until the stop. I repeated the process several times until I had to push it beside me.

Then I waited for 10 minutes and plugged it in to 220V. At the start of charging it showed 125V, 11.5A, the Kill-A-Watt shows 1670 Watts from the 220V plug.

For you experts out there:
1. Did I do a correct full charge? (I did a full charge yesterday and today for cell balancing)
2. Do you think 125V, when plugged-in, is OK voltage? I had it rested for 10 minutes prior to start of the charging and I guess it regained some voltage.

siai47
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Joined: Monday, July 21, 2008 - 19:27
Points: 91
Re: Battery Performance

The batteries will be fine at 125 volts. With 102 cells 125 volts equates to 1.225 volts per cell (assuming a perfectly balanced pack). A NiMH battery can be safely run down to 1 volt per cell without damage. That being said, if you have no further reason to do a deep discharge (state of charge indicator working correctly) try to limit deep discharges to extend your battery life. Be sure to let the battery pack cool down if possible before you start the recharge. Figure out how long it takes to recharge after an average ride and set a timer to start the charge cycle so that it will complete just before you need to ride the next day. If you let the Vectrix charger complete it's cycle you have done a correct full charge.

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