What's in a camera battery?

What's in a camera battery? After my Cuba trip, I decided it was time to dissect the third-party EN-EL3e that has been nothing but a nightmare.

So here I pried it open. I used a blade to cut along the glue line between the bottom and top covers. If you do this, be careful not to cut too deep. After cutting a slit, it was still hard to remove the top cover as it was glued to the batteries.

There are two blue cylindrical batteries inside. Each battery carries 4 volts. They are joined in serial fashion to give 8 volts. The photo shows two dark bands of sticky glue.

There electronic circuit board seen in these picture control the actual output and communicate battery information to the camera. It could cut out the current as well. These two blue batteries are perfectly fine. They do register 8 volts total but the output from the circuit board is nil. I had suspected that some logic board in the battery is faulty. It looks like my suspicion has been confirmed. Why though? No idea. Cheap, third party battery. In photography, you really get what you pay for.

The blue batteries stand the same height as normal AA batteries. However, these blue batteries are fatter as seen in the last photo below.

One thought came to mind. What if I remove the logic board? It could work but it could destroy my camera too, and how would I recharge the batteries? Would they need the logic board? The recharger knows when to stop recharging -- how? These questions will remain unanswered because I am not about to test it out. Removing the logic board could damage my camera. While the battery information is not too important, I think the board does regulate the voltage and current output. I am not sure and am not about to attempt it. :)

For now these blue batteries could serve as emergency batteries for flash lights or something like that. Their voltage output is rather high but usually the flash lights take 2 or 3 AA or AAA batteries. They amount to 3 to 4.5 volts, so these blue batteries could still be useful. When they go depleted though, I wonder how they can be recharged. I could stick them back into its original battery case with the logic board and charge them in the normal Nikon battery charger, I guess.