2nd meeting Barcelona - recharging comparison

Hi!
We had a good chance to compare 3 bikes during the 2nd Vectrix meeting in Barcelona.

All 3 have started in the same place,
...

But they might not have had a similar state of charge (SOC).

I recently realized how much the discrepancy between perceived SOC and real SOC is influenced by periods of inactivity.

At some point, an algorithm to account for self-discharge and constant-on state of the MC was introduced to the Vectrix firmware as an add-on.
But as far as I can see the amount of self discharge was significantly under-estimated.

Therefore, different useage patterns can lead to (reversible) different range and voltage situations. In extreme cases, like storage for months or years without regular cycling, there will probably be permanent damage to parts of the battery.

But from the data you present in this post so far, I cannot draw the conclusinon that one of the VX's has permanent battery damage.

It can obviously not be excluded, either!

I bought mine in June this year, and it was a 2008 model. So, I'm not sure, but it's possible that my V had been resting for a certain while too.
I didn't have the feeling that anything was wrong with it, but now after a few months and 2400 km done, I'm almost certain that it's range has gone up.
In the first weeks afer I received it I dindn't drive conservatively, I must admit. It's just too much fun to enjoy the Force:-)
But back then, when somebody inquired about the range, I used to say: I'm happy if I get 45 or 50 km (with that driving style). But, I had made a round trip to a near big city, and got 55 km after explicitely driving slow, also not accelerated fast (just to be sure to get back home, I did, but just barely).
My commutes are short, and after reading wise words from the 'Vizzards' on this forum, I learned to recharge sooner then I did before + do a full discharge every say 14 days.
It seems to do good, because I can say now that I'm confident to make a trip of 60+ km, and the estimated range after a deep discharge + full recharge went up to 80 km!!
I never actually achieved more then 65 km, but I think I could, if only I had the patience to make a long trip without giving in to the addiction to the Force:-)
I don't think, however, that my bike has been neglected, it may have sat there (in Poland??) for a while, but they knew what to do I guess. Charge regularly when stored..
Maybe there's still hope for Aleix's battery, he has only done 600 km so far..
But then again, with some damaged cells, the problem will only get worse..
Am I right Mik?

With "periods of inactivity" I meant times when the owner is not riding the bike.

Recently I went on a holiday for two weeks, and on returning the Vectux was charging differently.

The hourglass showed full for one second, then dropped to 16/17th when I first turned it on.

That was not a big enough drop, though!

The battery was much less full than that, and it took over a week of daily driving until it got back to where the hourglass shows full when the battery is full.

The charger stops charging when the display says it's full, even if that is just wishful thinking!

A BALPOR would reset this, but with the severe capacity imbalance in my battery pack I cannot do this without further severe damage to the weakened cells.

I just did several full charges including the CC and EC phases, and the final voltage gradually crept back up to the usual 147 or 148V. I also gave the weak cells a full charge through the M-BMS, at 3 A, until they all hit 1.445V and began to heat up. The weaker cells probably have a higher self discharge rate.

So for your group of VX-1's, this means that you would need to ride them under very similar circumstances for the same distances etc for about a full week, then let them all have their automatically scheduled equalization charge, and then compare the range.

Well, that's me. I have finally registered to V's. Thanks for all the replys.
The bike is used daily for a 24Km city commuting.
I try not to accelerate hard but I sometimes like to feel "the force" as well.
I recharge it every night, except for Fridays. I keep it at mid charge until sunday night, to get it ready to go to work. I bought it on last july with only 1015Km on the counter, 1 year from the registration date, and a 4 year extended warranty. They had a stock of more than 9 bikes comming from an spanish region "vehicle electrification" program. The total ammount of EVs of the program was a little less than 70 (not all were Vectrix, some were Oxygen Cargo Scooters for the postal service). A number of them were equipped for local polices.
They had been stored for about 6 months. After 1 week of daily commute I attended the first meeting. I was very happy at the destination with my 5/17 remaining bars. But talking to Roger and Raj we realized that I had only 121V. I had been about to run out of battery at Garraf's cliffs, like another unit that came from the same vendor in the same circumstances. It had two riders and lit the red battery 6Km before the end of the trip, after a steppy slope. After listening to my colleagues advices, I made two consecutive deep discharges and the battery indicator seemed to show the real state. On the second meeting I arrived with 5/17 as well but 5V more, 126V. On my way back I reached home with just 2/17, 6Km of estimated range, and 126V as well. Batts temp was 31C while ambient was about 19C (last 3Km were uphill at 70-80Km/h).
Of course, I don't have the chance to test the range Daily. The two 2009 VX1 at this group make over 100Km daily and have the best range. I'll keep you informed of my battery progress.

In order to not to get into trouble because of the battery indicator misinformation, I tried to produce a spreadsheet to check the voltage readings against the battery indicator. The data is the following:

Sorry about the language, it's in Catalan, but figures are easily recognisable.
Even though it might no be exact, It has proved to be quite reliable for bike. Any comments will be appreciated.

Thank you for the information. Can you make a bigger screenshot, please?

Hola Aleix, bienvenido a V!

Roger, i do 2 consecutive deep discharges (only uptill the battery light turns on, not further) every 2 months more or less.

My range has increased, i dont know if its because the gearbox has become smoother or because the battery is more "fit". I used to get 55kms and maybe 5km remaining, and now i can easily do 60km and maybe 5 or 10 remaining. Lets say 65km in the safe side, thats perfect for me because i only need a 50km range daily, so in this way i wouldnt be draining the battery to the end. Now after 50kms i end up with 4 or 5 bars, all this in normal driving, not thrashing it but going at 80km/h for 30kms and city 40-50km/h 20kms. If i let the "force" loose i reach home with 1 or 2 bars and hot batteries, because i end my comute going up a slope for 1km
Rajesh.

Hola Aleix, bienvenido a V!

Roger, i do 2 consecutive deep discharges (only uptill the battery light turns on, not further) every 2 months more or less.

My range has increased, i dont know if its because the gearbox has become smoother or because the battery is more "fit". I used to get 55kms and maybe 5km remaining, and now i can easily do 60km and maybe 5 or 10 remaining. Lets say 65km in the safe side, thats perfect for me because i only need a 50km range daily, so in this way i wouldnt be draining the battery to the end. Now after 50kms i end up with 4 or 5 bars, all this in normal driving, not thrashing it but going at 80km/h for 30kms and city 40-50km/h 20kms. If i let the "force" loose i reach home with 1 or 2 bars and hot batteries, because i end my comute going up a slope for 1km
Rajesh.

I recommend you to do a (real) deep discharge (until vel<24km/h) every 1000km and a shallow discharge (until red light) every 500km. Official recommendations are that you should do a shallow discharge every week and a deep discharge every month (the long equalization should happen this time). For your daily range, this is almost the same thing. I also recommend that you do not let the battery goes bellow 20%. It helps the lifetime of the battery.

R, yes, actually one of the reasons i am happy about the Vec is that i use it as my everyday transport (i bought it for that), and for the moment its responding perfectly.Its practical, fun etc.. etc.. If it continues in this line, it will have been a good decision in the economical sense after about 5 years. Lets wait and see.

Jmap, 20% of the battery would transalate to 3-4 bars, precisely it only gets discharged untill 4-5 bars, so i am at the limit there!

So, what i do, is that the day i feel like "racing" i do it on my way to work and then return in a very calm way. Just a ferw rare days that i "race" all the commute. :) Its so much fun to let loose and forget about range and battery life, and then not so much to feel abit guilty about the battery heat and discharge... abit like getting drunk and then the hang over, nearly always worth it! Hahahaha :)
Raj

Hi again,

I've made a quick translation of the range spreadsheet into English.
You may download it as:

• PDF from http://www.volttour.net/vtdocumentos/2009/Vectrix_Range_Check_EN.pdf
• XLS from http://www.volttour.net/vtdocumentos/2009/Vectrix_Range_Check_EN.xls

Feel free to use it. If you make corrections please post them !
This sheet is intended to:

• Help the rider check if the bars shown correspond to the real remaining battery charge, and apply a correction factor. Very useful when the bike has not been used for some time (due to self-discharge)
• Have an estimation of the remaining recharge time from a given amount of bars (note that the charger uses the same "bars" reference to stop the charging process)
• Have an estimation of the remaining range, depending on the cruising speed and the number of riders. Be careful, slopes and riding style may completely vary the range

I has been useful to me. Enjoy it!

Are the Voltages in the table read immediately after stopping the bike or is that a standing Voltage, after some time?

For example: when I stop and read the Voltage it reads 128V, but after an hour, when I turn on the bike, it reads 131V.

Hi AndY1,

The figures on the spreadsheet are theoretical. The voltage for each bar comes from chopping 17 times (bars) the difference between the maximum and minimum voltages. So they are a rough try to guess if when I'm seeing 7 bars I do have that energy stored in my battery, or otherwise I only have 4 and won't reach my destination ;-(
This is what happened to a colleague on our 1st Vectrix Barcelona Meeting, and had to get towed back home, missing a delicius supper.

When readings don't match the spreadsheet, I have to make a full discharge to reset the "bars counter" as it has been said on previous posts. But this way, I only do it when necessary, on an evidence basis.

Lead batteries (and Li I guess) have the same behavior. When you let them rest, voltage raises slightly, but if you use them again without recharging it drops fast to the same level. So I check voltage inmediately after use.

Hi!

Disappearing bars sindrome happens because the battery bar gets unsynced with the real battery State of Charge in a way, that shows the battery charged more than it actually is. This happens over time (500-600km). If you check the cut-off Voltage of CP stage - after a full recharge after the red battery telltale, the CP stage ends at aprox. 151V. With kilometers done, this end CP Voltage, which's end is regulated by the batter bar, gradually declines. Mine, after 600km done, after a full red battery telltale recharge, now stops at 145V, but the battery bar gauge shows as battery full, which it actually isn't. Those are the missing bars, that disappear at the end of the ride, when the battery bar gauge is out of sync.
That's why, the Vectrix, incorporated into the new software, that after 12 hours of riding, to the regular charging process, a 4 hours of 3A EQ charge is added. See here.
3A = C/10. Doing that for 4 hours will charge you 40% of the battery. So, if I assume, that my battery bar gauge and the real batter SOC are off by aprox. 20% and I also have 10% imbalance in the cells, then the lowest SOC cell is only 70% charged when the bike thinks it's charged. This 4 hour EQ charge will, again, fully recharge the battery to the 100% SOC, including those imbalanced cells. The cells, that are, before the EQ, 80% charged, will dissipate heat, those that are at 70% , will continue to charge until they are at 100%. At the end, the whole pack will be dissipating heat, but at C/10 and enough cooling, at once a month, that should be ok. This is a crude way of balancing cells, because the Vectrix doesn't have cells balancer, because it would be extremely expensive. 6 LiPo cells balancer costs 150 EUR. Vectrix has 102 cells and is doing balancing by way of overcharging, which shouldn't hurt the cells at C/10. However, you can't do overcharging to LiPo cells and balance them this way, because they will ignite. LiPos have to be balanced be the way of electronics.

If your friend did the EQ part of charging, prior to your ride, or at least some rides before your ride, this wouldn't have happened.
I also don't recommend doing 'to the red battery telltale' discharge before the EQ charging phase. It's because the cells before the EQ is initiated, go so unbalanced, that you might actually bring 1 or 2 of them to 0 Volts. The best practice for the 'to the red battery telltale' discharge is, to do it the first ride after the full EQ charge is complete. At that point, all the cells should be balanced, so that when you reach the red battery telltale, all cells should be equally empty. That is, if you don't already as damaged battery pack as Mik's, where some cells already have significantly lower capacity as the rest of the pack. In this case, as Mik is practicing, never do a 'to the red battery telltale' discharge at all.

Very good explanation!

Hi R,

As discussed, I've been having amongst other random errors, reducing range, now down to 35-50 km per charge. I got nearly 50km today, a recent record. I checked the voltage at full charge - it was 141 V. Down from 149 a couple of months ago. On the way home from the city, after having driven hard (70-85 km hr and up some quite steep hills) I killed the engine as you described and found the temp was 25 degrees C and the voltage was 125 V. I rode the bike until the busult message appeared and it was doing just 20km hr (up a small hill). Temp was then 34 degrees and I've unfortunately forgotten the voltage.

Thanks for your insights!

Hi!

Disappearing bars sindrome happens because the battery bar gets unsynced with the real battery State of Charge in a way, that shows the battery charged more than it actually is. This happens over time (500-600km). If you check the cut-off Voltage of CP stage - after a full recharge after the red battery telltale, the CP stage ends at aprox. 151V. With kilometers done, this end CP Voltage, which's end is regulated by the batter bar, gradually declines. ...
...

It not only builds with actual kilometers driven, but also with days or weeks standing!

In my experience, the problems get multiplied by periods of inactivity.

On the other side of the same coin, there can be problems with heat accumulation with frequent use in hot weather.

Ideally, a Vectrix should be used daily and the battery cooled to ambient air temperature level between uses.

Has anyone tried out yet if the equalization charge can be kept "on call" by always interrupting it with a timer, until the time when you want it to happen?

Has anyone tried out yet if the equalization charge can be kept "on call" by always interrupting it with a timer, until the time when you want it to happen?

Yes, I've already tried that: interrupting the EQ makes the bike try to EQ again next time you plug in the bike.

Can this be repeated kind of endlessly?

If yes, then you could just use a timer so that you can always begin an equalization charge when it suits you!

Another question: If the EQ charge is interrupted towards it's end, does it start over again?

If yes, that would allow to do several EQ charges in a row, for example when resurrecting a Vectrix after winter hibernation.

Dear belrose

Down from 149 a couple of months ago

I'm suspecting that you saw 149V during EQ phase, I'm afraid that if you don't remember in which charging phase the bike was, this information is not useful at all.

I got nearly 50km today

This 25C after driving hard looks promising, and tells me that you have the last SW installed. Good. The 50 km range after driving hard is starting to look normal also. Maybe the EQ charging is recovering your cells.

unfortunately forgotten the voltage

Don't worry, when the busult message appears the battery is around 117-118v. This 34C in the last riding part worries me a little. The battery suffered a 9 degree jump when getting empty, you may have weak cells. I still don't know what's the best for you: replace the weak cells, put a BMS only in these weak cells, or just put a voltmeter to monitor if the weakest cells suffer a dangerous voltage drop and learn the new safe limit of you battery.

On the other hand, somebody in this forum (I can't remember who, I apologise) suggested to perform a 0.25A charge during 2 days to get all cells balanced, it seems a good idea to me (let's wait and see if all people agree). By the way, do you know somebody in Australia with suitable electronic equipment to perform a controlled charge like that?
Cheers

An immediate increase in battery temperature towards BATHOT, when getting empty is an indication of a cell failing. I got BATHOT at 5-6 bars left with my previous battery pack. That was the cell that was reverse charged.

Exactly, i can comfirm that at least for 5 times the Vec will always try to Equalize.
About cutting the equalization towards the end, its the last thing that should be done because the Battery reaches temps of 38c and as "R" has already said, it desperatley needs to get cooled down immeadiatley.
So imagine if it had to do all the EQ process all over again, you will end up frying the Battery.
If you need the bike, its better to interrupt the process at the begining, and if you know the bike is going to do an EQ, then make sure you dont have it in the sun or there is hot air around it, because you will end up with a 40c hot battery.

What if you interrupt 5 minutes before the end of EQ cooling (1 hour cooling after 4 hours of EQ?
Will it try to EQ next time around or does it consider Equalized immediately after it has completed EQ charging?

Can this be repeated kind of endlessly?

Yes I've tested four times in a row, and always tried to perform again EQ.

If the EQ charge is interrupted towards it's end, does it start over again?

I've interrupted once in the middle and it started again. Don't know in the end part. -I suggest to avoid interrupting towards the end, the Bat is pretty hot and needs the terminal cooling phase.

Excellent!

With an ABCool that is no problem at all! It's a feature...