36V-10AH LiFePo4 Charger-Controller Issue

[dsesler]

When I plugged in the charger for my Golden Motor 36V-10AH LiFePo4 battery last night there was a huge spark. I'm not sure what happened, but bottom line is that the battery connector pins are damaged and I'm guessing the controller and/or charger is fried.

Any troubleshooting suggestions? Is it possible to buy a controller and charger and rewire everything, or am I going to be stuck having to buy a new battery?

 

[Ypedal]

Goldenmotor have been posting on here lately, see :

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=9939&start=0

Might want to reach out to them :wink:

the battery itself should be fine, the BMS and/or charger could have issues ( maybe reverse polarity problem ? )

The expect the motor controller would not be affected by this event..

 

[dnmun]

what did you do different this time that caused it to spark?

how did it behave before when you charged it?

did you do something else to the pack that you did not mention? like adding wires or changing the plug?

 

[dsesler]

Nope. Nothing was changed and I did not think I did anything different. They shipped the battery and charger with this really odd connector with about 20 pins. The connector was awkward but functional, I was always having to fiddle with it to get it lined up properly. My best guess is that I somehow managed to touch the battery positive pin to the charger ground pin, but that is just a guess. I really do not know what happened, but whatever it was, it was big. The current flow was so huge it melted down one of the pins on the battery connector.

 

[Ypedal]

Got a digicam !!!?

 

[dnmun]

i saw one of those last week for the first time. capacitive balancing, has both leads for each cell going from the charger to the BMS, with 2 processors on the BMS to manage each end of the pack, like two 24V packs in series, even has separate shunts for each end, with 5 surface mount resistors in parallel for the shunt.

we need pictures and you need to figure out which wire it is and where it goes, like in how could it have shorted?

it could be that the charger is bad now, maybe not the battery. keep looking, how bad is the plug damaged, do you need to replace it or is there an extra spot to replace that pin? i thought the reason they used those plugs was to make it foolproof.

 

[dsesler]

I'll take it apart this weekend and post some pics.

 

[dnmun]

what do you have to open? is your pack plastic wrapped or box? just pictures of the burned pin and trace it back to the charger, maybe you won't have to open the pack yet. but we love pictures, and i will compare the pouches to brandon's too. you may not have any real problem yet, just a damaged pin which blocks charging.

 

[biohazardman]

GM used to have many problems with QC on the battery packs they sold. Check inside the pack for shorted wires near the plug and switch several have had trouble there. Also, check the voltage at each battery to see if one of them is the problem. My communication with them was slow but it did eventually happen. So keep trying with the e-mails regularly if you are after a replacement and be patient. I have seen it take over a month for many to resolve their problems. Good luck with the pack and be careful, as they can be a fire hazard.

 

[dsesler]

I pulled this pic from their website, its a pretty good shot of the connector, and what I have to take apart. It should not be too complex, but I want to wait until I can have a couple of hours undisturbed so I can take it apart correctly.

 

[dnmun]

the one i saw had a buncha individual wires, see how good a close up you take of the plug, with the boogered pin. it may have just shorted to an adjacent pin and it will work when it gets straightened out, or it may not fit tight enuff in the plug if is is damaged, and a little burnishing or filing will help, but see if it can be plugged in somehow first and then look at the charging lights to see if they will light, that may offer a clue initially.

 

[dsesler]

Ok, so I tried to take the battery apart this weekend, but I forgot about photos until it was too late. Sorry about that. That 20 pin connector really does have wires running to every single pin (it looks like its about 20, I did not actually count them). All of the wires connected to the connector are black, with no color coding. You would have to be extremely careful if you ever wanted to replace that connector.

I decided to try the easiest thing first, which was to take some fine grit sandpaper and file down the melted portions of the two pins that got fried. It took a couple of hours because space was so tight, but in the end I managed to get the pins filed down well enough that the connector matted back up to the charger connector. I plugged everything back in and the battery seemed to charge up just fine, and I commuted in this morning. So far, so good.

I still do not really know what happened, but I'm going to be much more careful about making sure the guide pins are aligned before trying to mate the connectors. It would be a shame to have to replace a battery after only 850 miles!

 

[dnmun]

that's great, i figure if i can fix stuff, everybody can. but i break more stuff than most so i get more practice.

 

[dsesler]

It turns out I spoke to soon. I thought all was well, but the battery is not taking a charge. I still have no idea how I would figure out whether the issue is the charger or the BMS.

Anybody have any advice? Can I buy a matched BMS & Charger anywhere and just rewire the battery pack I have?

 

[Sacman]

Can you get to the back side of the connector on the battery. Or maybe you can release it from the battery case with all the wires still attached on it's back side. Can you get access the back sides of both battery and charger connectores? If you can do this then plug both battery and charger connector together and use a meter to check continuity with your test leads on the back sides of each connector. You should be able to identify which pin(s) are not connecting and need repair/replacement.