Best Battery Setup

[travist]

So I did some searches, but the best battery posts all are several years old already, I'm assuming things may have changed since then.

I have a cargo trailer conversion (or will soon, bit of a delay on delivery of the cargo trailer), and the big deal is I am using a dc-only fridge: https://www.homedepot.ca/en/home/p.60-c ... 88238.html

which you can see uses about 20 Ah a day. I have a 40W solar panel that should offset that usage somewhat. all lights will be led, and so then I really only have a 12v pump left.

So, with that in mind, what is the best battery set up and batteries for the unit in your mind? 1 or 2 batteries? 6 or 12V? AGM or Flooded, or Lithium etc? Brand?

Thanks everyone.

[John61CT]

The best battery **value** by far is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club.

Deka-labeled same batts also sold at Lowes.

[John61CT]

Very few 12V FLA are proper deep cycling, and **very** expensive per AH.

AGM are fussier to care for, shorter lifespan and more expensive.

GEL can last long, but otherwise, see AGM.

LFP cost 5-7x more up front, so would need to last decades to get payback, pretty risky even if you're an expert.

[John61CT]

Read this https://marinehowto.com/what-is-a-deep-cycle-battery/

everything electrickery at that site is canon, gold

[GuitarPhotog]

Very few 12V FLA are proper deep cycling, and **very** expensive per AH.

AGM are fussier to care for, shorter lifespan and more expensive.

GEL can last long, but otherwise, see AGM.

LFP cost 5-7x more up front, so would need to last decades to get payback, pretty risky even if you're an expert.

AGM are fussier to care for... Huh? What?

My 60AH AGM in my teardrop is maintenance free, does not out gas, and doesn't corrode the terminals. What's fussy about that? My first Interstate 60AH battery lasted 6 years, and survived one "down to zero" discharge. The second such event killed it, after 6 years of use in my TD. I just don't see any fussiness in there.

<Chas>

[tony.latham]

Very few 12V FLA are proper deep cycling, and **very** expensive per AH.

AGM are fussier to care for, shorter lifespan and more expensive.

GEL can last long, but otherwise, see AGM.

LFP cost 5-7x more up front, so would need to last decades to get payback, pretty risky even if you're an expert.

AGM are fussier to care for... Huh? What?

My 60AH AGM in my teardrop is maintenance free, does not out gas, and doesn't corrode the terminals. What's fussy about that? My first Interstate 60AH battery lasted 6 years, and survived one "down to zero" discharge. The second such event killed it, after 6 years of use in my TD. I just don't see any fussiness in there.

<Chas>

Are you charging directly from your tow vehicle?

Thanks

T

[John61CT]

AGM are fussier to care for... Huh? What?

My 60AH AGM in my teardrop is maintenance free, does not out gas, and doesn't corrode the terminals. What's fussy about that? My first Interstate 60AH battery lasted 6 years, and survived one "down to zero" discharge. The second such event killed it, after 6 years of use in my TD. I just don't see any fussiness in there.

I meant the spec'd charge profile is much tighter to optimize longevity.

Must get to 100% Full (as per endAmps) more frequently, hydrometer is not available so increases the need for an SoC meter, high current is needed for longevity, overcharging can easily wreck them since you can't replace lost electrolyte, they're not really sealed, just outgas less.

Of course AGM is fine, sometimes even necessary.

My points are just relative to FLA.

Note the OP title.

[GuitarPhotog]

I charge from a PD4045 when AC is available, and from a Morningstar MPPT solar charge controller when not. I have a solid state SoC meter built-in to the system, and seldom see the SoC below 70%.

<Chas>

[John61CT]

Good setup

seldom see the SoC below 70%

That's the biggest factor in longevity. Easy with a tiny setup like that, but

doing so with an 800AH bank would mean carrying around a lot of extra weight

[tony.latham]

I charge from a PD4045 when AC is available, and from a Morningstar MPPT solar charge controller when not. I have a solid state SoC meter built-in to the system, and seldom see the SoC below 70%.

<Chas>

Thanks.

On this next build, I think I'll add a switch to turn the charging off while towing and stick with the solar controller unless we're moving and it's at a low charge. (I can only recall one campground that we've stayed in the last ten years that had hookups. I guess we're hillbillies.)

Tony

[travist]

I will charge via the converter panel when at home, and tow vehicle will likely charge while transporting.

I realistically will maximum get out 8 times a year, and probably only 3 or 4 of them will I do an 80% discharge. If I'm honest, refilling batteries sounds annoying so I'd rather pay for AGM.

Are the Duracell batteries AGM?