New to 12v fridge
I'm looking for some real world experience and advise. I just purchased a 2023 Jayco 25rb and it has a 12v fridge and no solar onboard. The battery they gave me was a 63 amp hour flooded battery. We ...
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You have to check your specific fridge but ours pulls about 50w (4amp@12v) when running and run maybe 50% of the time (depends on outside temps). So typically, we use around 50amp-hr in a day.
Of course, you will also have lights, water pump and other draws but the fridge would typically be he heaviest draw. Doing an energy audit estimating what you will run while boondocking and how long each item is running is a good first step.
You shouldn't take a lead-acid battery below 50%. Also, when charging with generator, it doesn't take long to get up to 80% but above that, battery acceptance tails off quickly. The result is, you would need to run the generator many hours to get to 100%...result is you have around 30-50% of the rated amp-hr as usable (50% if starting from full or if boondocking multiple days, 30%)...so your 63amp-hr has about 20amp-hr usable.
If we assume you did an energy audit and came up with 75amp-hr per day used, you will need a lead acid battery bank of around 250amp-hr.
In contrast, lithium batteries can be drawn down to around 10% without harm and can charge fast right up to 100%. The result is you need 85-amp-hr of battery.
So long as your battery charger (converter) can do lithium, a 100amp-hr battery with built in BMS are running under $200 on amazon. I've seen some down near $100 but I can't vouch for the quality. 250amp-hr of lead acid will be at least $200. Another benefit is weight (always a consideration with RVs). 100amp-hr lithium will be around 25lb. 250amp-hr of lead acid will be maybe 150-200lb.
Your current battery system is inadequate so an upgrade is needed. I would seriously consider lithium.
valhalla360 wrote:In contrast, lithium batteries can be drawn down to around 10% without harm and can charge fast right up to 100%. The result is you need 85-amp-hr of battery.
that is kinda misleading it, you are not hurting it by tanking it to 0%, and there is no reason to be afrade of doing so. the rated life span of a LiFePO4 is based on cycling from 100% to 0% many many times. I think the older batteries I was working with that had a 3500cycle life, if you cycled then twice a weekend for 33 year they would at that point only have 80% of the capacity left. ther new ones coming out are being listed as 8 to 10K cycle life. all staying above 10% does is give you a bit more cycle life than they are rated for, so ya it is good practice to stay above 10% but your not doing damage by going below.
The point is still the same, you can use most of the rated amp-hr in a lithium which means you can use a much smaller battery bank and still have the same amount of USABLE amp-hr. Heck, when you buy them, they automatically jump you up to 100amp-hr anyway.
