Dead batteries - Bike will not power up.

[sunchaser]

Hello.  I went to check the SoC on my "parts bike" Enertia after winter storage and it would not power up.  Before storing it I charged to about 50% - 60% and forgot to check it during the winter.  That was obviously a big mistake.

I checked the individual batteries and four of the six of them had no LED activity at all.  Not a good sign.  The remaining two had a green flashing LED.  The voltage on all of the batteries was really low.  Roughly 3 to 5 volts each.  I charged each of the individual batteries with a 12 volt automotive battery charger and was able to get all six batteries up to 12 volts or more, but the red flashing LED remained on the same four batteries. 

After putting everything back together I plugged in the bike and it started to charge.  I didn't have any error codes but I'm wondering if it's because of the fact that I haven't tried to put the bike into "drive mode" by raising the kick stand, switching the headlight on and turning the power switch to ON.  It would surprise me if the bike allowed the batteries to charge if there was some kind of fault or error, but that's just a guess.

Unfortunately I really can't put this bike into drive mode due to the fact that the motor was removed because of a bad bearing.  I guess I could still try it but at the very least I would expect to get errors related to the motor and controller not communicating.

Does anyone have any advice on this?  Any help would be appreciated.

Thanks.

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Update - Hooked up the motor underneath the bike temporarily to see what would happen.  I was able to get the bike to go into drive mode and had no error codes/messages.  Twisted the throttle and the motor rotated as it should. 

The bike shows 34 miles of range remaining which I seriously doubt after the severe discharge of the batteries.  Unfortunately I still have the flashing red LEDs on the same four batteries.  Obviously I can't test drive the bike with this current setup.

Very strange.

[KaFr]

I found a manual for the Valence U-Charge module on the Internet. It says a little about the colors of the status diode.

[KaFr]

How much did the SoC show on the display, after you charged the battery modules with an external charger and plugged them back into the serial circuit?
And what was the minimum and maximum cell voltage?

BTW: When the electric motorcycle is not used for a long time, it is strongly recommended to disconnect the traction batteries from the circuit using the main connector. This ensures ist almost zero self-discharge.
The only disadvantage of the traction batteries disconecting is that you can run out of rechargeable batteries in the VCU after some time. This battery is charged from the traction batteries when the motorcycle is switched on only.

[sunchaser]

Thanks for the Valence information KaFr.  You're really helpful as usual.  I appreciate it.

As for the SoC after externally charging the batteries, I don't remember exactly but believe it was around 60% or so.  When I charged the bike with the internal charger up to 99%, the voltage was 82 if I remember correctly which sounds low to me.  I thought that it should have been closer to 86 volts.  The high cell was around 3.6V and the low was around 3.4V.  I also noticed that the charger was putting out the full 9 amps even at that high an SoC.  Usually it starts to taper down after 90% or so on my main Enertia, although I've seen that bike do the same thing.  It's also interesting that the bike that was manufactured roughly six months later charges at 9 amps rather than the 8 amps of the slightly older bike.  The cooling fans on the newer bike are also considerable louder and have a different sound. 

I also remember seeing the same red flashing battery led after accidentally letting the SoC get low while riding the bike and seeing the "batteries low" message on the dash.  That's only happened once or twice and now I rarely let the batteries discharge less than 50% if I can avoid it. 

I'm going to try discharging the bike with the headlight on to that point and then recharge.  Maybe I'll get lucky and the batteries with the red leds will reset.  At best I'm sure that I've significantly reduced the capacity of these poor batteries.  Very disappointing. 

I thought about trying to contact Valence (now Lithion Battery Inc.) but doubt that they'll be willing to provide any useful information. 

Yes, I most definitely should have unplugged the high voltage disconnect prior to storing the bike.  Believe me, I regret what happened.  Needless to say, the batteries are by far the most difficult (and expensive) part of the bike to replace. 

[KaFr]

You don't have to thank me too much, I will also be happy to learn something new from you :-)

From what you write, there are unbalanced cells in the modules. Imbalance is greater than 0,1V.
The upper voltage at full charge should be 3,75-3,8V.
So I would try to leave charging for a longer time even at 99-100% SoC to balance the cells. If that doesn't help, I'd discharge the batteries to 50-60% and try charging them 100% again. It is important that the imbalance at 100% is less than 0,1V.

Do you have any photos from the procedure of removing the engine from the motorcycle frame, please?
It would be very useful.

[sunchaser]

Trust me, you know far more about these bikes than I do, but thanks anyway. 

Yes, I agree about the cell imbalance.  I've discharged the batteries to down to 20% to see if they would display the red LED that I remember seeing in the past.  Unfortunately that didn't happen.  All six batteries have the same LED condition as before.  On a positive note, I did get the "batteries low" message on the display when discharging down to 20%.  I'm in the process of charging the batteries once again to see what happens.  I also sent a message via the company contact form to Lithion Battery Inc. but am not expecting a reply.

I also suspect that my batteries aren't going to reach the 3.75-3.8 volt level due to the damage that I've caused, not to mention the voltage reading of around 3.6 volts that I previously had after charging to 99%.  I guess we'll see what happens.

I read about a special Valence procedure for recovering batteries that have been severely discharged but I haven't been able to find it online.

One of the things I've noticed with both Enertias is that the cell imbalance seems to increase when the SoC is greater than about 90%. 

[sunchaser]

As for the electric motor removal process, I started another thread with the steps that I remember.  It isn't a perfect guide but better than nothing.

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More photos.

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Well, my discharge/charge experiment was a failure.  The batteries charged up to 99% but would not enter the balancing stage.  I think that it is due to the large imbalance between the cells.  The high cell was around 3.75V and the low was 3.40V.  The other thing that I noticed during the charge was that the current would repeat a cycle that started at 1 amp...2 amps...4 amps...5 amps...up to 9 amps until the high cell would reach 3.80V, and then the cycle would repeat.  I stopped the charge because it didn't look like the low cells were ever going to reach anywhere near high  cell voltage.  After sitting overnight I powered the bike up in charge mode (without plugging in) and looked at the cell balance.  The pack voltage was 78 volts and the high and low cells were around 3.34 to 3.40 volts.  This was at a 99% SoC. 

It looks like the severely discharged batteries are damaged and never going to reach a true 100% SoC again.  I still have the red flashing LED on the same four batteries as before.

Let this be a warning to those who store their bike for extended periods.  Check and charge the batteries often!

[KaFr]

Cell imbalances do not necessarily mean that some of them are destroyed. It is possible that only their capacity and thus the health of the battery module (SoH) has decreased. It may or may not be irreversible. I have experience with my Peugeot E-Vivacity, which I have not driven for a long time, so one of the two battery modules has become more discharged than the other. When I started charging, it ended up at about 70% SoC for the first time and then charging stopped. When I discharged the batteries while driving and started charging again, the SoC increased to 75%. So it gradually improved until I reached 100% SoC again after several cycles of charging and discharging.

[sunchaser]

That's good to know.  Thanks for sharing the information.  Maybe there's still some hope for these poor batteries.  The thing that concerned me the most during the last charging session was the cycling of the current that I described when the SoC reached 99%.  That was really unusual.  It was as if the charger didn't know how to deal with the condition of the batteries.

I've been thinking about making an RS485 (I believe that's correct) for the batteries and trying to connect to them with the Valence software.  There are tutorials online for the U27 series batteries, but they have a different connector than the U1.  It would be helpful to know the cell voltage of each of the individual batteries.

I started a new thread for the creation of the battery cable and Valence software.  If anyone has any information to share it would be appreciated.

[sunchaser]

I just spoke to someone at Lithiumwerks who was helpful.  She said that if the batteries dropped below 5 volt then they likely have cell damage and are not recoverable.  The procedure for attempting to recover the batteries is to charge them at 1.0 amps with a 12 volt charger and try to get them above 5 volts. 

The rep that I talked to said that she was going to forward my contact information to their engineering department.  I also asked about the RS485 cable pinout.  I'll report back if I get any useful information.

Oh, by the way, new batteries are $700 USD each.  Ouch.