Hello Dave ... Three things. First, and I don't know why more cruisers don't have this, is we have a Sea Frost engine drive compressor that cools a large holding plate in the frig box, our box is 7CF. We also have a Sea Frost Freezer Bin inside the box, that is a 12V system. The Engine Drive is incredibly powerful. And we move around a lot, rarely are we in one spot more than 2-3 nights. Our cruising is exclusive Bahamas, southern. Unlike Maine or New England, where you can pretty much sail to & from the mooring ball, as you know in the Bahamas, going from one island to the next generally involves a bit of distance, and most times 30 minutes or so of motoring in & out of Cuts, getting to and from where you want to be. During that time setting & picking up the hook and moving around, the engine is on, and the ED compressor also is on. 20 to 30 minutes in the morning and again in the afternoon is all we need to keep that Plate frozen solid. The 12V system, which is thermostatically controlled, generally won't come on for 24 hours after the engine & ED Compressor are shut off, and often times longer. And it will keep the entire Box cold for weeks without any help from the ED, but this rarely happens. I also always run the 12V system at MAX coldness while the engine is running.

So for instance, if we motor into Big Majors one afternoon with the ED on for 30 minutes, the box will stay cool for at least 24 hours with no help from the 12V, and probably longer. So we stick around there a few days, then make a run to G'town. By the second day at Big Majors, the 12V starts to work, but not much, and during our trip to G'town, the ED comes on in the morning, and late afternoon (assuming we got lucky and were able to sail the entire 60nm distance with no motor until we get to Elizabeth Harbour, then the engine, and the ED comes on for 45 minutes by the time we are settled. Again, the Plate will stay frozen until at least the next evening, when it's cooler, so probably not really come on for 36 hours or so. We don't have a watermaker, so invariably we need to head into Kidd Cover, provision, and get water from Sugar One ... so, the ED comes on again, and no or very little net Ah are consumed.

The second thing we did was completely and properly custom rebuild our box, with at least 4" of insulation, 5-6" on the bottom, and vacuum panel hatch & door from Glacier Bay. Ample & proper Insulation and new gaskets will go a long way in reducing Ah from a Frig Box. These units are spendy but well worth the cost IMO. I have a thermometer outside the box which gives me inside temps away from the Plate, we don't run it that cold, maybe 40 degrees, but it barely moves on the hottest of days. The Freezer Bin is about the size of a shoe box, we can get a bunch of meat, fish & chicken in there, and I make ice with a Sea Frost ice tray that we stack between the Bin and the Plate, so we always have ice too. In my opinion, production boxes suck, no matter who the boat maker is. Get in there, rip it all apart, and do it right ... you'll be pleased.

The last thing is whenever the engine is on, that is when we charge everything by way of Inverter. I'm sure the engine appreciates the extra load.

I often wonder what kind of increase in overall performance we would see if we were in New England, with cooler temps, colder water, and more gray days.

Other than the obvious ... opening the Box as little as possible and asking others if they would like anything from there before you do; Keeping the box absolutely stuffed; We defrost the Plate & Bin every few weeks which greatly increase efficiency, and we run a small battery powered RV fan inside the box ... We'll even go to the trouble of putting our provisions in a restaurant's big refrigerator before bringing them onboard. Our anchor light is an OGM, it draws .25AH, we also use Bebi lights for an anchor & cockpit, plus LED lights throughout. We don't leave instruments on, our pumps are not often used, our Head is sea water and we don't have comforts & gadgets like water-makers (although I wish we did) microwaves, coffee-makers, WiFi antennas, TV and so on. We don't use the computer for any NAV stuff, that's a biggie. The stereo is not often on, nor is the VHF unless we're moving, and I'm on the SSB, generally receiving and not transmitting, for maybe 30 minutes in the morning getting weather on days we move. We have a new water heater from ISO-Therm, it does have an electric element that we never use, it will give us comfortably hot showers for 3 days after the engine has been turned off.

Here's a secret > We also use MAC computers, and I found these very cool iGo 12V chargers for them made by Mikegyver.com. I don't know how he does it, but our MAC's now charge via the 12V (cigarette) receptacle, not using an inverter, and they charge 2-3 times faster with half the amount of draw than using 110+Inverter.

We also have a HO 125A ALT, which helps. So, I'm sure our Ah usage is quite a bit more than 50-60/day, but I don't really count that because the extra happens with the engine on while we are moving, so I consider that free. I log our daily use every day by way of a LINK 20 monitor, and the 50-60 average is what we net out. Some day, I'd like to have solar, even a small panel would top me off every now & then. Finding a place on our boat is an issue. But until we start slowing down and spending several days in one place, not moving, the system described above balances our needs fairly well, and keeps our Ah use to a minimum.

Hope we see you this year in the Bahamas Dave ...
Cheers, John