i have bought a military battery at a yard sale and i want to use it as a backup battery, i have successfully discharged from it using the positive and negative holes but i cant seem to charge it using the same method can anyone try to help me?
the positive is the upper hole and the ground is the bottom hole, does anyone know whats the hole next to the negative is for?
In general, lithium batteries are always charged with what is called a "Battery Management System" or "BMS" for short. That's because lithium batteries need to be charged very, very carefully under strict control. Otherwise, some can rupture, catch of fire, and have killed people! Airplanes have crashed because of lithium battery fires. I suspect that third connection is for monitoring the charge being given. Don't just try to jumper some 12V charger wires to it and expect it to work properly.
Please don't try to actually use/charge this battery until you've contacted the manufacturer to find out exactly HOW this battery should be charged.
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