Dual cell mod and discharge problem (cell reversal).
How long have you dual cell modifiers had you car moded this way and how long have your batteries lasted. There is a real problem with doing the dual cell mod and it is called cell reversal. The car never shuts off and will drain the battery to 0 volts. When you build a battery pack and discharge it to 0 volts it is a very good chance that you will reverse the polarity on one of the cells because it will discharge lower than it should. I would think that the only way to successfully perform this mod would be to put a switch so you can shut the power off to the PCB.
You're not wiring the battery parallel. You wiring it in series. I'm not sure about the theory of reversal but it is no different than running you walkman or portable cd player that uses more than one battery.
Linear Mode
