Originally Posted by Rescue Wagon
I did a bunch of reading on the AOPEC Smart Battery Isolator and it looks like a good choice, but there is one thing I'm having a hard time verifying. Does anyone know if it has diodes on each of the battery legs to truly isolate the batteries from each other or is it just a relay?
I can't be 100% certain, but it looks like it uses a relay contact. It looks to have electronics to sense when there is a high voltage, that is, the charger is charging, then it fires a relay.
I've thought this over a number of times is I tow a small camper with a 12 volt battery in it. Diodes alone aren't a good idea. They keep the voltage at the battery too low to get a really good charge. I now have a schottky diode in line with the battery in my camper. The schottky diode has maybe a 0.3 volt drop. The system wiring adds a few more tenths of a volt. My motorcycle battery is around 14.2 volts. The camper battery probably never sees much more then 13.5 volts and the battery just never gets a good top off. I actually need a system to boost the voltage a little for a good charge on the camper battery. A relay would work better in my case.