Running ebike on turbo trainer

[Springforward]

Any comments on this welcome, I have 4 bikes and run them on a turbo trainer to hopefully keep the batteries in condition. I always run at a medium power setting/middle gear on CD bike, 12/15 mph on panel and nothing gets even slightly warm. I let them run down on throttle till half the bars are out then charge. Recently a 48 volt battery has given trouble despite being only a few months old and low miles. It cuts out, switch light goes out, switch off/on and it restarts ,this repeats. Leave switch untouched at fail point and after a short time the switch light glows dimly. Repeat as above. 350 watt CD, 48v 11.6 ah samsung cell battery, controller rated 7amp, max 15a. voltage at fail is around 50. Conditions- warm workshop . Is this a BMS fault or has this type of running been a possible cause of damage. Thanks in advance from a newbie but long term reader.

 

[Jon NCal]

It's possible the BMS is cutting out due to one cell group hitting the 3.0V level. How is the battery doing after a full charge? Is it still reading the full 54.6v or perhaps slightly lower than it has been previously?

 

[MadRhino]

Modern batteries don't need to be discharged periodically. They can sleep all winter, as long as they are within storage charge level and temperature. When they are plugged on a BMS and/or a controller, they need to be recharged to storage level once in a while, because they slowly drain. That is all the maintenance that is required during storage period.

So, there is no need to run your ebike on a trainer. You only add useless cycles to your battery, that has a limited number of cycles. Other parts of your bike are the same, they just wear. Your bike is not a horse, you don't need to exercise it to keep it in good shape.

 

[Springforward]

Thanks for your response, I reckon you are right. The battery has been sent to Insat in London uk for test & repair as required so I have no recent voltage readings. I do recall that it was down a bit being just over 50v. I will post the result as it may be of help. The other bikes are OK so possibly not the turbo trainer running being the cause. Any other thoughts on this way of keeping batteries over the winter or best just to top up the charge each month .
Thanks also to Mad Rhino, good advice which I will follow. Learning something each time I visit here.

 

[nutnspecial]

Your bike is not a horse, you don't need to exercise it

I found that nearly hilarious lol, (es quotes?)

Any other thoughts on this way of keeping batteries over the winter or best just to top up the charge each month .

If I understand, most bms'd lithium packs would require full charge to balance, then put back into storage voltage- you'd think they'd have a 'storage-balance' function though, it'd be nice. Eitherway, if you can confirm all cells at proper voltages (50% soc?) during a monthly check, no other action is needed. My fridge has batteries of many chemistries and various glues etc etc.

Sidenote, I never expected some flip phone batteries to discharge all their electrolite in the freezer- don't know wth was up with that. Lithium is supposed to be okay @ freezing esp when dormant, but maybe the 40F fridge is safer.

 

[Springforward]

Update for anyone interested. The battery was returned with a completely new Samsung 29e cell pack and BMS at no cost to me. I can only conclude that the original was of unsatisfactory quality . I would deal with this supplier again without hesitation as they stand by their products and honour their warranty .

 

[flat tire]

As others have noted this is hilariously unnecessary. Just set the batteries at storage voltage if you need to leave them.