Canadian Tire 20V Yardworks Battery Short and Fix BMS

[zukster]

I was setting up a new battery and I accidentally shorted the + and - when I
was attaching Anderson connectors. Its easy to do. Prob should do them one
at a time or tape any stripped wires until the Anderson housing case is attached.

The check lights do not light any more and there is no voltage on +,- pins.
There is 20.7 volts on the C and + pins, so something is probably
shorted inside, or maybe I fried the BMS stuff.

I got a little carried away with the glue gun attaching the quick connects to
the battery terminals, so I'm not sure if I can clean it up to try a warranty
replacement. And it was my fault anyway, so I think I should try to fix it.

Anyway, I got stuck already trying to open the battery. Security Torx bit
is needed. Anyone know which size it is?

Edit: Already found this info

Torx is T8, you need a driver at least 7 cm long and less than 7 mm or 1/4". For $4.99 I got Cdn Tire part number 57-3315-0. It's 3" long and works fine.

If its just a wire that needs replacing, I can handle that. But what can I
do if the BMS is fried? Any suggestions are appreciated.

 

[rkosiorek]

maybe the pack has a fuse sealed inside. try that first. if it does not have a fuse and the BMS is sealed or "potted", then you may be out of luck.

if you can't repair the BMS you may have a few spare cells to use for future replacements or cells.

rick

 

[zukster]

I hope it has a fuse. I off to pickup the T8 torx now. Hope it works. I'm going to
get another battery while I'm at Cdn Tire too. Just-in-case.

 

[zukster]

I should have paid more attention to the generous pics that philf posted in my
other thread that shows the 30amp fuse on a little white plate right where the pins
plug into the battery.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=9451&start=15#p146338

Looks like I'm lucky. My fuse is just blown.

Re Torx T8 from Canadian Tire for opening the battery. I picked one up and it worked for
2 of the screws - but a couple stripped. So I'm not sure if T8 is exactly the right
size. There are metric and Imperial Torx.

Anyway, I ended up using a small flat screw driver, from one of those little screw
driver sets, and it actually fit in better than the T8 when I found the right one.

 

[Anonymous]

.

 

[karma]

for any future problems theirs also a surface mount fuse on the bms as well. :wink:

 

[zukster]

for any future problems theirs also a surface mount fuse on the bms as well. :wink:

Yah, but its a real bitch to replace that fuse. Took me a lot of effort and very careful soldering.

I'm starting to think of the batteries as something to use, just they way they are. I attach some
quick connects to the pins, then shrink tube the whole thing with 5 inch shrink tube. If a battery
dies, just take off the shrink tube and return it for a new one.

You can buy 5 inch shrink tube from here if anyone is interested.

http://www.buyheatshrink.com/heatshrinktubing/2to1polyolefin.htm#B

I bit the bullet and bought 25 feet of the 5 inch because it really makes things easier.

 

[docnjoj]

Wow Zukster! That stuff almost costs more than my Fatpacks. I'm just using lugs and electrical tape for tests, but once I know my 4 packs work I gotta find a more elegant way to seal them. That polyolefin stuff is outrageous! Or I'm just cheep!
otherDoc

 

[zukster]

Wow Zukster! That stuff almost costs more than my Fatpacks. I'm just using lugs and electrical tape for tests, but once I know my 4 packs work I gotta find a more elegant way to seal them. That polyolefin stuff is outrageous! Or I'm just cheep!
otherDoc

Believe me, I tried a lot of other stuff before I gave in and ordered some shrink tube. I tried black tape, duck tape,
silicone tape, shrink wrap, and this econo stuff that Justin at ebikes gets from the battery manufacturers themselves:

http://ebikes.ca/store/store_connectors.php (At the bottom)

It turned out to be really brittle and hard to get on nicely. The black tape was the best before the shrink tube.

I'll post some picks of the shrink tubed batteries and the slide on rack that has two batteries attached so you can see what I mean better.
Just have to find my camera

 

[zukster]

Okay - here's why I went to extra lengths to waterproof the batteries with shrink tube.

They're the same size as before, but now waterproof, so they fit compactly onto the bike.

In these pictures, I have two attached 2x20V=40V to a slide on seat post rack. With the Keywin 36V
Infineon controller, that's all you need. Although 3x20V=60V goes a lot faster, it weighs more too.

You can see the controller taped onto the back of the tri-frame, just under the rack.

Ignore the other batteries taped to the inside of the tri-frame. I was just testing this as an even
lighter possibility, since you would not need the rack, which is about 1kg.

I prefer just using the 2 battery rack, because its lean and clean, and allows you to slip the
rack off the bike to charge them in the house.

 

[karma]

nice waterproofing :wink:

 

[zukster]

I have a couple of more batteries to do for my daughters bike. I'll take pictures of the
process in case anyone else wants to give it a go, it will same them some experimenting.
So stay tuned.