2013 Zero XU Battery Problem, Possibly More. Seeking Help

[fechter]

$3250/ea (and both of mine are dead).

Yikes! more than the battery for my Honda Civic Hybrid.

If this is a common problem, it is going to be very bad for Zero's business. From what little I know, it's possible this type of failure can happen from manufacturing defects inside the cells. Bad process or cell design and not necessarily from how they are used.

A DIY replacement pack will definitely be less expensive but a lot of work.

 

[eee291]

I'm tempted to fix your battery. If you could send me one of
those, I could replace the cells for much less.

 

[robby]

$3250/ea (and both of mine are dead).

Yikes! more than the battery for my Honda Civic Hybrid.

If this is a common problem, it is going to be very bad for Zero's business. From what little I know, it's possible this type of failure can happen from manufacturing defects inside the cells. Bad process or cell design and not necessarily from how they are used.

A DIY replacement pack will definitely be less expensive but a lot of work.

I'm tempted to fix your battery. If you could send me one of
those, I could replace the cells for much less.

Another ES user has borrowed my dead (and disassembled) battery to attach the BMS to another battery he has. Assuming he is successful in doing that, we are going to see what that yields when connected to my bike.

How would either of you go about rebuilding this pack? The cells are epoxy-encased and the case itself is bolted to the cells within the epoxy. Would you dremel away at the copper contact? Is there a solvent that would remove the epoxy but not pose a hazard when exposed to the cells? If you go the dremel route you have to build a whole new BMS harness as well. Seems like a ton of work but maybe there is an easier way I'm not seeing.

 

[eee291]

Rebuilding the BMS harness isn't that difficult. My brother is an expert welder, I'd have him recreate the battery box if necessary, assuming it doesn't use some proprietary locking system to hold on to the Zero bike. And if it does I guess I could still try to reuse it. I mean it just looks like a bunch of studs from the pics so I'm not too worried.

About the epoxy, It'd be a lot of work. But if I'm lucky I can just break it out, There is a Acetone with heat method, but I don't think I'll have to resort to such things.

The only thing I'd be stressing about is getting the right thermal probes.

 

[fechter]

I think getting the BMS out undamaged would the the key. Everything else you can make yourself.

There are different kinds of potting with different characteristics. Most of the clear stuff I've seen resembles epoxy and is hard as a rock.

If you gently heat an area to 60C - 100C with a heat gun or boiling water, the epoxy will soften and become rubbery, at which point you can dig it out using a small straight blade screwdriver. You don't want to heat over 100C or you could damage the components. Dig fast as the stuff gets rock hard as soon as it cools off and you need to re-heat.

If you are lucky, you can free the BMS without damage and maybe even clean out the box so it could be reused.

I would also recommend trying to totally discharge the pack cells as much as possible before digging around.

In the past I have tried all kinds of solvents, but anything that even comes close to working is highly hazardous. Heat worked much better.