3rd Party Batteries

[Moseph]

I've been renting an A1 from my school for quite a while now and I broke one of the batteries that I took out with it...by dropping it on my living room floor which has CARPET! It was not an OEM battery, if it was, it probably wouldn't have broke from that. So I took a multimeter and discovered that the battery was putting out something like 4 volts, and then I took the initiative of tearing the thing apart to try to fix it, thinking that a connection could have been broken. I was wrong, it was actually a little circuit board that had something wrong with it apparently, because the cells themselves were outputting 8 volts.
So then I figured, ok, I gotta make this right, and I went on ebay and bought another non-OEM battery for 25 bucks. Should I have spent the extra money? Probably, but it is outputting 7.6 volts, before I have even had a chance to charge it. But, I noticed that instead of there being 5 contacts on the battery (labeled +, -, T, B, and D (the last 3 I have no clue about)), like the one I broke, there were only two, labeled + and -. What were these T, B, and D contacts even for? Will I have any major problems?
Thanks.

 

[adolgin]

The additional contacts are safety related and for communication with the camera. The T contact is for connecting an internal temperature sensor to the charger. It is really not needed in the 99% of situations, but if somebody decides to charge the battery in 100 deg heat, it is not good for it, so the charger will limit charging. If you can charge the new battery on the charger, and the camera does not reject the battery, you are OK to use it.

 

[Moseph]

Great, thanks for the help. I figured I'd probably be ok, it just seemed rather shady, especially since this "7300 mAh" battery obviously has only 4 cells inside the thing.