First I think some clarification is required here.... Devil is in teh details.
To make a 12V LFP Battery Pack, it takes 4 LFP Cells, a 24V Battery Pack requires 8 LFP Cells.
Placing Batteries in SERIES increases Voltage: 12V/100AH+12V/100AH=24V/100AH.
LFP Batteries in Series is NOT Recommended because most BMS' will not accept that and it IS risky.
Placing Batteries in PARALLEL increases Storage Capacity: 12V/100AH & 12V/100AH = 12V/200AH
You can have 2-10 Battery Packs in Parallel within a Bank, even more BUT then you are into complex BMS' (Battery Management Systems)
LFP Batteries in Parallel are perfectly fine as each "battery" acts as an "independent agent" if properly designed.
Things do become more complicated as you add more packs (full batteries) into a Battery Bank.
RV's / Campers are mostly all 12V & 120V and so you will need to provide 12V to your existing equipment. If you use a 24V system you will need a good 30V to 12V Step Down Converter (NOT a cheap Buck Converter) and
YES, it must be 30V to 12V because when charging the battery bank, it will be just below 29V. And it will have to be able to deliver the Amperage required to operate your RV equipment. Many RV'ers do use 24V very very few go to 48V.
Look at this document I prepared in our Resource Section, on Assembling your own LFP Packs, as well as some other links like the LFP Voltage Chart in my Signature will help you on your path.
This document was posted to the forum by Amy from Shenzhen Luyuan and written by Steve S. It was meant to be posted as a resource. Below is her description of the resource: Dear all friends in the forum, This file in the attachment was...
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Some NOTES: LFP Cell sizes & weight vary by capacity & manufacturer. RV's typically have a dedicated space for the batteries and as such is limited. Get Good Measurements to know the space you have to work with. You can buy LFP cells from 10AH to 1,000AH, currently the most popular are the 280AH cells which are 9" Tall and 8" wide 2-3/4" thick. 8 Cells in a straight line is 23-1/2" long X 8" wide. A "Block" pack is 16" wide X 11-3/4" long. Each 280AH cells weighs 5.2kg/11lbs.
Confusing Point to clarify.
Battery Packs in Parallel are no problem when wired up properly. They will share the Load & Charge capacity and improve the fault tolerance & fail over should anything go awry..
Battery Cells in Parallel within a Battery Pack is done to increase the "pack" AH Storage Capacity. ONLY properly Matched & Batched cells should be used if this is the plan, never Bulk Commodity cells which is what 95% of the Vendors sell. Properly Matched & Batched cells mean their characteristics are the same throughout their operating voltage & load ranges for Internal Resistance & Impedance. They more or less will "March in Step" as they operate. Matched & Batched cells are More Costly but definitely worthwhile for critical systems (like an offgrid residence).
We have a few KNOWN GOOD Vendors and we know of MANY Shlock Floggers selling Bulk Cells as "Matched". What 95% of the vendors will tell you is they are matched, BUT they are
only Voltage & Static IR tested - (THIS IS NOT A PROPER Matching).
I will recomend Luyuan Tech who is a Very Well KNOWN Good Vendor (Good enough that I wrote the above guide for them, and I do not do such thing unless they are Genuinely Credible).
Shenzhen Luyuan Technology Co., Ltd., Experts in Manufacturing and Exporting Lifepo4 battery, LTO battery and 0 more Products.
szluyuan.en.alibaba.com
Good Luck, hope it helps.
Steve_S