I have decided that a tank circuit would be the best way for me to power my carputer and I am mixing, matching and modifing other peoples ideas from this great collection of threads. I think that I would like to use a second car battery as opposed to the SLA battery that most people seem to be working with due to the fact that I have one and I have the space for it. I do, however, have a question about my setup. All of the schematics I am looking at (the good ones at least) have a resistor between the main battery and the backup battery to limit the charging current to 1/10 or 1/4 (depends on whos schematic) of the SLA battery's Ah rating. So, I am thinking that as long as my backup battery had the same Ah rating as my main battery, I would be OK without the resistor, thus limiting my tank circuit to two diodes and some wire. Am I correct to assume that this would work without frying anything?
My circuit is pretty much like Ricky327's (http://www.mp3car.com/vbulletin/show...highlight=tank) minus the resistor and replace the SLA battery with a match of the main battery. Ricky seems to know his ****, so I figured that would be a good place for me to start.