[coolhandcountry]

There is no diodes on them brian. It is a straight wire from one battery to the other. Same thing on a tractor trailer with more batts. I have seen up to 4 batts in series. I not sure what you mean by cross charge. If a battery is 12.6volts and the other is 12.4 volts you start the car or truck it will draw more from the higher volt system. After the vehicle is running it charges the lowest one first and then brings both up equally. If you want a pic I can get one off brother in laws dodge :D