E8035 lifespan - anyone experimented with the internals?

[rpurdie]

I have a couple of E8035, one was replaced under warranty and is therefore newish. The other one is now three years old. The range on it is rapidly worsening, it is capable of around 70% of the range of the first battery. At an enduro event this year with the same course each day, I was a whole stage climb short on the second battery on the second day. I'm guessing Shimano will not entertain a warranty discussion on it. The idea it could have 60% capacity at 1000 charge cycles is a bit of a joke to be honest.

I could (and may yet have to) buy a new battery but it is a bit painful when I know that:
a) Shimano make newer batteries with better technology in the same size footprint (EN805) which won't fit
b) I can't upgrade the motor without upgrading the batteries at the same time

It once again got me thinking about the internals of the battery/motor/display. Does anyone know if you disconnect the cells and power down the BMS whether it ever works again? I've heard that they don't power back but it is hard to confirm. I'd be game to try re-celling it if there was a decent chance I'd not destroy it. I was reading about the serial data exchange someone else logged for charging and I'm interested in looking more into that.

I don't suppose anyone has any old unwanted Shimano E8000 parts they'd be willing to donate to some experimentation? Could really do with some of the connectors, scrap battery, scrap display to experiment with...

I'd been thinking about buying a new bike but the ones I like have Shimano and I'm not sure I can bring myself to buy another one given the current siuation with the motors and my experiences at the start of the year.

 

[Zimmerframe]

Is there anything in here which helps ?

Re-Build ande Re-Cell of Shimano Batteries

There is very interesting information regarding batteries in the thread for E8000 Motor Repair: https://www.emtbforums.com/threads/steps-e8000-motor-service.16542/post-444917 and forum member @fuikatasio has suggested not to mix topics and to open a new thread related only to batteries. I...

www.emtbforums.com

 

[rpurdie]

Is there anything in here which helps ?

Re-Build ande Re-Cell of Shimano Batteries

There is very interesting information regarding batteries in the thread for E8000 Motor Repair: https://www.emtbforums.com/threads/steps-e8000-motor-service.16542/post-444917 and forum member @fuikatasio has suggested not to mix topics and to open a new thread related only to batteries. I...

www.emtbforums.com

Thanks, I have read that. It looks like they could disconnect the BMS in that case, the question is whether that is possible with the E8035. I'm also not sure if there is a capacitor on the board which keeps the BMS alive but if it discharges, you're in trouble. I'm not seeing companies willing to re-cell these batteries and there must be a reason why which is what worries me a bit.

I should add, I did disassemble an E8035 and it is really easy to cut the cable going to the front button/LED. Sadly, I did break mine. Now I know how it goes together, I probably could get one apart safely but that could be the reason people don't touch them, not sure.