Good Article on the Necessity of a Fridge

[Vic Harder]

I thought we'd live with one of our supercoolers for at least a year after buying our Hawk, but then Engel had a sale so a 45qt topload fridge found it's way into our camper. Replaced our 45qt cooler but has so much more room since 1/3 of it isn't filled with ice. We'll not go back to a cooler. If the fridge ever broke on a trip, which is unlikely, we'd just buy a cheapo cooler and ice and keep on truckin'. No big deal.

We have two agm batteries totaling 150amp/hr. Before buying solar panels and controller, i bought and wired a trimetric monitor since we wanted to know exactly how much power we were using before sizing our solar. With fridge, furnace, lights and fan, we use about 30 amps a day, so even without any charging, our batteries could go 2.5 days and still be at a safe 50% state of charge

We then bought our setup and I installed it. I have about $500 into the 180watt panel, bogart 2030 controller, bogart trimetric monitor, shunt, temp sensor, breakers and wiring. In the summer, we are back to 100% battery state of charge by 11am or so.

When controller is calling for bulk charge from panel and a high noon in July here in Montana, I'll see right around 8 amps from the panel. Now in October, I see just under 5amps max. We went on a trip this weekend and it snowed and was overcast and 25 degrees. The next morning, partly cloudy and the snow blew off the solar when we started driving. We went from 82% state of charge at 8am to 95%state of charge by 2pm as we drove around. I do NOT have the camper hooked to the truck battery/alternator. Never needed it. But i have it so i can easily hook it up if needed. I don't even prechill our fridge on ac power. I just turn it on and run it off battery while we load up the camper because the solar revs up and covers the charge plus more. Nice to not mess with prechill or hooking up battery tender in the shop since I drive my truck daily and it gets an hour or so of sun each day driving from one parking garage to another. Or if it is not 100% charged before we are going to leave on a trip, I park outside the day before so we are at 100% before leaving on a trip.



The trimetric monitor allows one to program the solar controller for ones specific battery brand. Exide gave me the exact perameters to use. I can program the custom charge parameters and get to a true 100 state of charge unlike my smart trickle chargers as they won't push the charge long enough before going into float. And the solar will do it fast. Less than $500 and it will charge as fast as a little generator with no noise, no storing it on a trip and no gas cans. Entire solar setup is lighter than our 1000watt yamaha generator.

Since we have batteries sized to get us through 2.5 days with zero input, we have not yet run into a situation where we've run low on power because even on overcast days, we get 10amps/day out of the panel and we rarely encounter 4 or 5 days straight of overcast and it only takes one half day of sunshine to have us back to 100%. As a backup plan, I can connect the truck wiring if need be. Since adding the solar, we have not brought along the little yamaha generator even once. We actually have so much excess power I'm going to get cables to extend to, and recharge, the trolling batteries on our fishing boat. And that is with a single 180watt panel that retails for about $160.

I love your approach Chad, in that you bought a monitor first to get clarity on consumption before investing in more batteries or solar. And then you sized your solar appropriately. Nicely done!

 

[munchmeister]

Is this the Tri-Metric being discussed by Chadx? Seems like a good idea as his experience is very positive. I'm just thinking about future purchases in the event a fridge finds its way into my Raven. Looking at a Dometic CFX28 12v Electric Powered Cooler, Fridge Freezer, currently $605 on Amazon.


Tri-Metric 2030-RV Battery Monitor (Amazon).

 

[Vic Harder]

Yep. There are flush mount and surface mount versions of this monitor. Get the one that is neatest/easiest for your application. The guts are the same.

That said, I and rando and Craig are all in favor of the Victron BMV712 as a "better" option. YMMV

 

[Chadx]

Yes that Trimetric is the one. As Vic points out, there are several brands that will get the job done. I think it is important for one to run a monitor before spending money on solar, larger battery packs, other charging options, etc.

So wire up a monitor, get to know how your current battery pack cycles with your normal use. It is eye opening. If you add a fridge, then you can see for yourself how many amps you use per 24 hours. Then take into consideration how long your trips are without charging, state if discharge in your batteries per 24 hours, how you currently charge, etc.

You may find that even with a fridge, you don't need solar. One or two day trips may not need it. Or longer trips where you drive every day. Or longer trips where one of your camp spots has plug in so you can charge.

Prices keep dropping so a small portable panel and small controller are quite reasonable. Even medium sized setup are reasonable and, nowadays, are less than the fridge.

As mentioned previously my 180 watt panel, the controller, the monitor, shunt, wiring etc. was about $500. Probably a fare bit less than that now. Watch for sales.

I used that size panel because it bridges the distance between the factory installed tracks on the roof. Made for easy install. Will probably put the camper on for the summer in the next few weeks and I again will not hook it up to the truck's charging system since the solar easily makes way more power than we use.

 

[JaSAn]

Probing around in my cooler with a IR temperature gun convinced me that a refrigerator is the safer way to go. If I put the ice on the bottom things on top would not stay under 40ºF in 80º+ temperatures. If I put ice on the top then stuff was sitting in meltwater and it was a pain to get anything. And ice limited my stay: I could get 3 days out of 2 bags of ice or 5 days from a block with the cooler wrapped in a down comforter (I have stayed out as long as 17 days with a refrigerator).

My 35 y.o. Norcold finally died this last fall so I just added ice for the rest of the trip and changed my diet and plans to accommodate.

Even with an old and inefficient refrigerator I was seldom below 80% (Trimetric reported) in the AM and was usually back to full by noon with 200W on the roof and 208AH of batteries. I agree with above that getting an amp counting battery monitor is a good way for a newby to learn his system. And after you learn your system it will also give an early warning of problems: increased power consumption was my first indicator that the Norcold was toast.

jim