So I was thinking today as I was driving,why can't we put a fused wire with a diode and a switch between the isolators. That way during storage, if you are plugged in it will charge the start batteries.
Would that not be the same as having the boost switch on?
A diode would lower the voltage too much.
Unless it's germanium. There are some fairly substantial germanium diodes out there. I used one as a blocking diode on the sailboat between the solar panels and the batteries. Found it at a surplus electronics outfit in Oakland, CA (which is no longer there).
Craig
We ran with your fused diode idea for over nine years and it kept our start batteries charged. This is the same idea that the very popular Trik-L-Start uses.
We are fine with the diode voltage drop on keeping our start batteries under charge. But with last year's hot summer we noticed that our Xantrex Prosine 2000 was float charging 100 degree batteries around 12.9 volts which is correct for hot batteries. But after diode voltage drop, we were not charging start batteries.
So we purchased, first a Magnum combiner, then BlueSea combiner. We ran each for several months. These smart combiners do not use diodes, so start battery was being charged at house battery voltage, which is a good thing. But because the smart part of the combiners have voltage sensing circuit boards to decide when to close & open relay they were disconnecting just under 13 volts, which did not charge our house battery during hot weather. So we were no better off than using simple diodes. We purchased Trik-L-Start and are back to doing fine again.
We have a switch on the Trik-L-Start to stop combining when we want to remove start battery cables for cleaning, etc. Nice to know that when we remove start battery ground cable that the start battery circuits will be dead. We put the Trik-L-Start, which is water proof on the isolator.
If using a separate start battery charger, it should be temperature compensated to keep start battery from being overcharged in hot temps.
Barry,
Did you put the switch in the ground wire of the trickle charge?
John,
I installed a 5A Battery Tender connected to the chassis batteries. The Battery Tender keeps a charging voltage on the house batteries any time 120VAC is available at the outlet into which it is plugged. I installed the small charger over a year ago. I've been pleased with results.
Thanks guys. Barry,I wondered about the temp issue too. Might just add a new trickle charge unit. Think the one I had on died. Will test that tomorrow or later today when I get into Nac.
Just replaced echocharger which died with a amp-l-charger, big brother to the trickle charger. It charges chassis batteries up to 15 amps. Works great so far.
That is great I will look for that.
Trik-L-Charge has 3 wires, house positive, start positive, ground. The ground wire may only be to light the indicator LED lamp and may not affect charging.
Our charger is connected to isolator terminals, with a switch on the start battery wire.
Thanks Barry,
Charger is already installed and connected to the isolator terminals. I have not put in the switch yet.