Refrigeration A25

[Sunsetrider]

I installed a 12v plug where dkirsop put his 110. I haven't had to use the ac power for the fridge. Three weeks now running steady on the 12v, but admittedly I have not set a freezer temp. Running at 6c., big compartment only.

[kerrye]

I'm giving serious thought to this. focusing on the Whynter dual zone. It's two inches taller than the Unique frig you are using. What was the price of the Unique frig/freezer? If it's comparable to the Whynter it might be worth the 2" reduction in height. However, from what I can see there aren't that many suppliers of the Unique frig/freezer. On the expedition forums, people are saying 80-100 watt solar panels and one battery will be adequate to keep these fridges running. You have quite a bit more solar power than that. Did you conclude that was necessary or overkill? We can use our alternators too if necessary.

[DesertAlbin736]

Looking forward to an in person inspection/demo next week upon arrival & some camping & kayaking on Sharbot Lake while we're at it.

[kerrye]

Looks like the Unique dual zone is $670

https://bensdiscountsupply.com/unique-u ... ezer-60-l/

[kerrye]

looks like group 31 batteries are a good choice

https://www.batteriesplus.com/battery/m ... m/sli31mdc

[kerrye]

Sunsetrider, can you post a photo of the frig installed in your boat?

[kerrye]

Another question:
It looks like the hardwood holding the sliders are sandwiched on the hull end by pieces of wood above and below. How did you attach those pieces to the hull and how easy was it? Did you consider glassing an horizontal piece of hardwood to the hull and screwing the slider hardwood down into that piece? Or maybe even using a piece of aluminum angle glassed to the hull?

[Beta Don]

looks like group 31 batteries are a good choice

https://www.batteriesplus.com/battery/m ... m/sli31mdc

The real bargain in marine deep cycle batteries is (and has been for many years) golf cart batteries

The above group 31 battery gives you 105 amp hours for $121.99. It's a standard deep cycle, flooded chemistry battery - Nothing special . . . . not an AGM or anything

Two $85 flooded 6 volt golf cart batteries ($170) in series gives you 12 volts at 215 amp hours, which is a good bit more electricity per dollar, but that's not the real reason they are the best value

Conventionally sized batteries are packed to the max with plates in an attempt to give you the most amp hours in the smallest possible case. Industrial rated batteries are not built that way. In a golf cart battery there is more room left at the bottom of the case, where the lead plates will eventually shed the material which shorts out the plates causing battery failure. More room left there means the battery will last longer. Also, at the top of the battery, golf cart batteries have an extra half inch or so of electrolyte above the top of the plates and that means when they boil off electrolyte during charging there is less chance the tops of the plates will be exposed, which also makes the battery last longer. Lastly, golf cart batteries are designed so that rocking and rolling and vibration doesn't loosen the plate material nearly as much - They know these batteries will get knocked around a good bit and they are designed to withstand more of that. They are heavy duty industrial batteries vs automotive battery technology. No comparison in how they are built

With a smart charger, regular checks to ensure you're not running them dry, the pair of golf cart batteries could easily outlast the group 31 by TWICE. 8 to 10 years in marine service is not unusual for golf cart batteries. I've probably installed a hundred pairs of them on customers boats over the last 30 years

One last thing - They'll last lots longer because you're much less likely to run a 215 amp hour battery down low enough to permanently hurt it than you are a 105 amp hour battery. As a rule of thumb, try to not go below a 50% charge, which means you only get to use about 50 amp hours from the 31, while you can regularly use more than 100 amp hours with the golf cart pair. Running a deep cycle battery too low really shortens it's life expectancy

Maybe you don't have the space, maybe you don't want to build custom hold downs for them, maybe you don't want to spend the $170, but if you want the most deep cycle DC electricity with the longest lifespan, I can't think of anything which would come close to matching what golf cart batteries will give you, dollar for dollar. They're still the biggest bang for the buck you can buy

Don

[kerrye]

It's the space issue. I'd like to get the battery(ies) under the refrigerator in what would otherwise be wasted space.

[kerrye]

Most of these refrigerators have automatic shut off devices which prohibit them from draining a battery to a damaging state.

[Beta Don]

Most of these refrigerators have automatic shut off devices which prohibit them from draining a battery to a damaging state.

The low battery shut-off is there to protect the refrigerator, not the batteries. In most cases, it's set around 10.5 volts which is essentially a DEAD battery - Not even close to a 50% discharge. A 50% discharged lead acid battery will measure 12 volts. A full charge is 12.6

Don

[kerrye]

The ones I've seen have a choice in cutoff points. Can't remember the choices but none was as low as 10.5 volts.

[kerrye]

Default setting on a Whynter is 11.7 volts. Not sure what the higher cutoff setting is.

[Sunsetrider]

Pic of my fridge.

[kerrye]

Thank you. It looks like the cabin door doesn't open quite as far as originally with the frig in place. Have you found that an inconvenience? And just to confirm, you had to cut out material at the bottom of the original opening to get it to fit but no material on the sides and top?

Considering the fact that the original icebox had to contain ice, there's a heck of a lot more room in your frig/freezer than the original icebox?