group battery type, 29 or 31?

[Lilyschools]

Im planning to build an electrical system, and dont know what type of batteries to get. Ill be running a 20L DC fridge, a maxxair fan, and i want enough to charge my electronics like a phone and laptop, and run LED lights. I planned on getting 3 100Ah 12v AGM batteries (group 31), theyre 180 dollars each. Could I get by with group 29 batteries? they have about 93Ah so only slightly smaller, but the price tag is much smaller. 
how many Ah do you have on board? Im going to be travelling full time in the summer, but i have an apartment in the rest of the year.

 

[DLTooley]

What’s the lower price?

For that 100ah price you are in the ball park of a self constructed LiFePo4 battery of a similar size and much greater depth of discharge and charge cycle life.

Xuba is a cell brand recommended here, Will Prowse at DIY solar has another. You can search this forum for more.

If price is a concern, go with traditional lead acid and wait for the LiFePo4 market to mature a bit more.

I do have assurance of quality concerns with the shipped direct from China product, but I’ll probably pull the trigger this spring.

 

[highdesertranger]

I have 450Ah in batteries. four 6v so I have 225 useable Ah's. Is there some reason you need AGM's, flooded are much cheaper. It sounds like 2 el cheapo marine batteries would work for you. Do the math, how many Ah's per day do you use and how will you recharge them?

1. figure out your daily power needs
2. size your battery according to #1
3. size your solar according to #2

that's a simplified way to start.

Highdesertranger

 

[user 423]

..how many Ah do you have on board? Im going to be travelling full time in the summer, but i have an apartment in the rest of the year.

This past summer I used two 31 series for a total of 200 ah to run a 20L fridge, occasional laptop use, just 1 LED light and to charge small batteries + misc. devices. Also powered was a speed adjustable PC fan that draws .5A max (much less than a Maxxair).

These were charged with 180W of solar and occasional use of a generator plus shore power a couple of times over the summer. The van did not have wiring connected to the alternator,so no charging help there (adding that now). There was one 3-4 day period when it rained a lot or was cloudy and they were drawn down to 12.2 volts.

What will you be using to charge your batteries?

Also; what type of vehicle will you be in? 3 AGM's will weigh 180 lbs.

 

[Lilyschools]

I will be using my alternator mainly, but am trying to source used panels off of facebook marketplace, 200W.
looking at a 2003 dodge sprinter 2500 high roof. Weight isnt tooooo much of an issue for me ( i dont think, at least ).

 

[Lilyschools]

What’s the lower price?

For that 100ah price you are in the ball park of a self constructed LiFePo4 battery of a similar size and much greater depth of discharge and charge cycle life. 

Xuba is a cell brand recommended here, Will Prowse at DIY solar has another.  You can search this forum for more. 

If price is a concern, go with traditional lead acid and wait for the LiFePo4 market to mature a bit more. 

I do have assurance of quality concerns with the shipped direct from China product, but I’ll probably pull the trigger this spring.

I just googled Xuba batteries, and im not sure if this is legit or what but if you could verify this is correct I would appreciate it. they are only 466 dollars, which is much cheaper than buying three agm batteries. 
https://szxuba.en.alibaba.com/produ...tml?spm=a2700.shop_pl.41413.10.10401d06fXyeep

 

[user 423]

$171 shipping.

 

[jacqueg]

I will be using my alternator mainly, but am trying to source used panels off of facebook marketplace, 200W.
looking at a 2003 dodge sprinter 2500 high roof. Weight isnt tooooo much of an issue for me ( i dont think, at least ).

Used panels? Be sure to look at Santan Solar in Arizona.

 

[Spaceman Spiff]

Im planning to build an electrical system, and dont know what type of batteries to get. Ill be running a 20L DC fridge, a maxxair fan, and i want enough to charge my electronics like a phone and laptop, and run LED lights. . .
how many Ah do you have on board?

I have 208AH of batteries (2 golf cart) and 200W solar.  It has been sufficient to run a 68L (2.4 cu.ft.) refrigerator, LED lights, cell booster, MaxxFan, 5KW bunk heater, laptop, phone, inReach, and occasionally other small electronics.  I currently have ~2500 cycles on my  batteries (6 years and 5 months) and they are still going strong.

If $$$ are a concern, you can't get any cheaper than GC2's: less than $200 for 200AH.
If you have the money and will accept some risk buying cells directly from China, building your own is the cheapest way to get LiFePO4 batteries.