Re: Battery Isolators
So...I take it you do that in your boat? So which battery do you put your sense on? So, what happens when you have a fully charged battery that has the sense on it and the other is severely discharged? I will tell you what happens...the other battery will not get charged fully or as fast as it could. Eventually, the deeper discharged battery will get up to the voltage of the fully charged battery, but it will take a long time.
The since line is on the starting battery and as soon as I start the engine it reached 14.4 volts very fast. My alternator is a 65 amp.
The deep cycle also reach 14.4 volts at the same time. While the starting battery has very little current going to it the deep cycle will have a lot of current going to it.
The voltage drop a crossed a diode is almost constant at .7 volts. A diode is not like a resistor where the voltage drop changes a lot with higher currents.
My deep cycle charges very fast as it will get 20 to 25 amps in the if it has a big discharge.
On my boat the deep cycle rarely has a deep discharge as I do not have a electric trolling motor. Ever if we are drift fishing from 6 am to 1400 and only start the motor for a short time to go back over the same area a second time your will not see any voltage drop.
I use the same meter to check both batteries with a spring loaded switch to keep it on battery one unless your holding the switch. With the motor running or stopper will see very little change if flip to the deep cycle.
We fish a lot in the ocean so is a 20 minute to 2 hour trip to get out and back in depending where we are fishing.
We usually fish for 7 days weather permitting when we go to the ocean camp ground.
When we get back home I fully charge both batteries thru the same battery isolator with my home 10 amp charger and it will take less than 20 minutes to taper to 0 amps. It will be fully charged long before we get the boat unloaded.