[Question] What does B+ and C+ mean on a Lifepo4 battery pack?

[abatonime]

EDIT: I think I posted in the wrong place. Can a moderator move my post to the right place please?

Hi,

I bought this Lifepo4 battery pack: link (http://www.aliexpress.com/item/lifepo4-battery-pack-24v-10ah/900478001.html)
It came with its own charger.

There are 4 cables coming out of the battery: C+, C-, B+ and B-. Both C and B have 26.6 volts.
I would understand that C means Charger and B means Battery.

The seller told me the charger has to be connected directly to the battery.
When I connected the charger (not plugged into the wall socket) to the C cables, there was a huge spark.

I am totally lost as what C and B really mean and the seller doesn't answer me anymore.
Do any one have an idea?

Also is it normal that there was a huge spark when I connected the charger ? (The fuse on the charger didn't burn).

Please let me know if one of you have any suggestion.

[Forgetful Jedi Knight]

Unfortunately, battery packs like that are not dealt with around here. Your best bet may be to either contact the manufacturer, or try Googling it, and see what you can find that way.

Good Luck.

[abatonime]

Thank you for your answer.

[Silver Serpent]

I'm pretty sure the big spark is not normal behavior. I've never seen lithium chemistry batteries that are supposed to do that. Quite the opposite really.

[Kun2112]

Don't know if you ever got your answer, but the additional leads on the plug are for load balancing.
When charging, LiFe packs above 3.2V need to be balanced so the individual cells charge to the same capacity. Otherwise one cell might charge to 100% capacity and the others might only charge to 70%.
The spark upon hooking it up to the charger is one of two things: 1 your charger is either not LiFe compatible, or not in LiFe mode. 2 the charge/balance plug is wired differently by that particular manufacturer. I had some A123 Racing LiFe packs that could only be balance charged with a A123 Racing brand LiFe charger.