I bought Nokia 8210 about eight years ago when it was the newest in the market. Its battery was Nokia BLB-2 Cell Phone Battery. It's a small battery but I have proven its high-quality performance. It provides long talk time and the phone conversation won't be cut-off due to battery-related interruptions. It has five to six days standby time. It uses advanced Lithium Ion technology and it is a rechargeable battery. During an almost an hour of phone call, the cell phone may heat up a bit but only two bars would be lost from the battery indicator display.
This battery is also used with Nokia 7650 8250 8270 8290 8310. However, when my friend's Nokia 3310 had an empty battery and she needed to make a call, she borrowed my battery. I was so surprised that it could power a Nokia 3310 cell phone though the 3310 had wider battery house. Nokia BLB-2 Cell Phone Battery is a very durable battery. It had never been bloated in my possession. I gave my Nokia 8210 to my niece after about 2 years and the original battery still functioned great when I handed the unit to her.