500AH Prismatic Cells

[Flentz56]

I really want to install LFP batteries in my RV, looking to start with battery bank, then configure to charge with the alternator instead of the generator. Finally installing a fixed inverter system.
I found these 500AH prismatic cells on alibaba, they would fit perfect where my original lead acid batteries now sit. Is buying these from China somewhat safe or really risky? I’ve asked them if these are new or used, they said new but have been sitting in the wear house for a year? Asked if they are grade A and they said yes.
I expect I would assemble with a 250 amp BMS from Daly, planning on installing a 2000 watt inverter. Want to set it up for charging with the RV alternator, it has a 185 Amp output, but I could get a higher output but I want to install a Renogy Dc Dc 50amp charger with Mppt solar, I’ll install panels later but 50 amps should charge this OK.

 

[Luthj]

Got a link?

I would suggest building some 280AH packs, and paralleling the packs for higher current (each pack with its own BMS). That gets you some redundancy, and makes the packs easier to handle.

Buying from Alibaba is totally dependent on the seller, as they are just a platform to connect sellers and buyers. Do your research.

 

[Flentz56]

I agree with that BUT space is limited, if I do that I will have to give up space somewhere. If I can build this pack it will fit where my battery already exists, I will need to insulate it for cold weather, probably put some type of heater for extreme conditions.


Check out this product on Alibaba App The Best Price LiFePO4 3.2V 500Ah Solar Battery Deep Cycle Battery
https://m.alibaba.com/product/60767...terKey":"7.8.2_share","cacheTime":"1800000"}}

 

[Flentz56]

250 per cell with 280 for shipping to my address

 

[Luthj]

Folks are currently getting 280AH cells for about 100-120$ delivered I think? So that's a bit expensive. I don't see a brand name or spec sheet from the MFG, so you may want to get that info.

What space do you have to work with? There are numerous ways to configure cells which may help.

 

[fafrd]

I agree with that BUT space is limited, if I do that I will have to give up space somewhere. If I can build this pack it will fit where my battery already exists, I will need to insulate it for cold weather, probably put some type of heater for extreme conditions.


Check out this product on Alibaba App The Best Price LiFePO4 3.2V 500Ah Solar Battery Deep Cycle Battery
https://m.alibaba.com/product/60767901183/The-Best-Price-LiFePO4-3-2V.html?__sceneInfo={"type":"appDetailShare","data":{"filterKey":"7.8.2_share","cacheTime":"1800000"}}View attachment 32828

Seems expensive for what you are getting.

Two 280Ah cells positioned side-by side delivers 12% more capacity for under half the cost and roughly equivalent volume...

 

[HRTKD]

I agree with that BUT space is limited, if I do that I will have to give up space somewhere. If I can build this pack it will fit where my battery already exists, I will need to insulate it for cold weather, probably put some type of heater for extreme conditions.

When calculating the battery size, you also need to consider how much space a compression frame may take up. I don't know if the cells you're looking at require/recommend compression, but most of the 280Ah cells that are being used by forum members do.

I put two 12v 4s 280Ah DIY LiFePO4 batteries into my RV. I spent a lot of time with a CAD program to make sure that they fit into the compartment I was using.

 

[Luthj]

Since LFP packs need to be kept above freezing to charge, in some cases I recommend RV applications don't use through floor compartments. Instead use the compartment for storage, and move the LFP pack into the living space in some lesser used compartment. The reason for this is many RVs used in winter conditions are kept heated which reduces the need for insulation and heating pads.

 

[Flentz56]

So, I measured it again and I could fit two separate 4s batteries in the box. The box is the one that was built for the RV, it is built into the access steps, made of steel and it is thru the floor, yes it has the potential to get cold. I believe I can mitigate the environmental condition, also I’m a fair weather rv’er.

 

[Flentz56]

So, I measured it again and I could fit two separate 4s batteries in the box. The box is the one that was built for the RV, it is built into the access steps, made of steel and it is thru the floor, yes it has the potential to get cold. I believe I can mitigate the environmental condition, also I’m a fair weather rv’er.

Built one 4S battery with 280 cells, decided on buying 4 more cells, building 2P 4S battery for 560AH, 250 Amp BMS with it.