No, how would you get the 110V down to the 12V needed for the fridge (assuming the OEM Adler Barbour).

One of our skippers installed a separate small battery, a second smaller charger and a relay: when he switches his main 1-2-B switch to OFF, the relay kicks in the wiring to the small battery and turns the smaller charger on.

The charger "working" doesn't hurt it, it's only 5A an hour anyway with the fridge load. No real "strain" involved.

You could also consider getting a 110V to 12V transformer.

[QUOTE=stu jackson c34;16578]
You could also consider getting a 110V to 12V transformer.[/QUOTE]

A transformer would produce 12V AC, the fridge needs 12V DC. So you'd also need a rectifier. I think by the time you bought the parts for that, and put it together, you'd pretty much have built what you already have (minus the charge control circuitry) eg., the battery charger.

Agree with the rest of your post. I've had my fridge on all summer for at least 10 years and the charger and fridge are just fine. Of course, I've now jinxed myself for spring launch.;)

[QUOTE=ggoetsch;16573]I would like to keep the reefer running all the time when at the dock but I am worried about the strain on the battery charger and the batteries. Has anyone installed a seperate 110 system that you could leave on when plugged in at the marina?[/QUOTE]

It's really not any strain on either charger or batteries, but I did find another problem. Somebody bumped into the dock cord, it didn't fall out but it did become electrically disconnected. I got back next weekend to find the fridge load had killed all batteries.

A dedicated battery would allow you isolate the ship's house bank. Maybe you could rig it so that the back-up starting battery did double duty for the fridge? Actually, the back-up start battery on my boat loafs all the time, as it is *never* used...it is only there in case the house bank goes flat.