FET Isolator vs ACR for simple charging systems

[Just Cause]

Originally Posted by Just Cause

I recommend that you go on U-tube, search for "Pacific Yacht Service" There is a whole series on this and related issues! It covers it all.

Sorry, "Pacific Yacht Systems"

[gpsatsea]

Thanks Waterman! I bought that charge assuming that it did isolate the batteries but have not yet read the specs or instructions.
Beside the extra wiring I think this is the best option. Once installed I will check the voltage drop to see how much of a negative that really is.
Thanks again.

[mitiempo]

Originally Posted by waterman46

My original post was made before I looked up the specs for your Promariner charger. My bad. The charger actually has programmable outputs for up to 3 different banks, so they must be isolated as far as the charger is concerned. Your wiring circuit showing the FET isolator looks good to me.

The Promariner has 3 outputs that are the same as far as programming is concerned. There are diodes so a charged battery doesn't dump current into a discharged battery.

Same as most other chargers.

[Jetx]

For a weekend boat frequently on shore power, I’d use an Echo Charger. Cheap, smaller wiring and fusing than needed with an ACR, and pretty bulletproof. Have to move the alternator output over to the house bank, but no other wiring changes needed.

[kenbo]

Comment on your wiring diagram, as said earlier, a simple amperage appropriate switch to parallel the start and house batteries is a good idea as is the switch between the start battery and starter. I would skip the 1 & 2 outputs on the battery charger and send the 1 output to the input terminal of the FET isolator.

The battery charger sense circuit should go to your house battery + and if possible the same for the alternator. But with a 35A OEM alternator I really doubt that's worth the effort. Do you know what the Vset of the internal regulator is? If it's lower than 14.2 VDC you'll never fully charge your batteries unless your motoring for days on end.

I like the simplicity of isolators especially if all the battery chemistries are the same ans the charge sense circuits are properly wired.