271 Ah upgrade

Freep wrote:

When we get home this week we're going to pack for a month of geographic distancing and if I don't need to use the generator once during that trip, it is slated for removal.

How much solar power do you have ?

I would still want a small (? 2200W) as a back up for cloudy days.

I believe that the OP is referring to LiFePo4 (Lithium Iron Phosphate) battery cells.

The term "LiPo" usually refers lithium polymer batteries. These are quite different physically. Instead of having a rigid (plastic) case the actually have a flexible, foil-type (polymer laminate) case (some actually look like a heavy plastic bag). The good part of this design is that it is very lightweight. The bad part is that they are much more susceptible to damage. Worse, when charged they swell. If the "bag" is constrained it may explode.

Lithium Iron Phosphate cells uses a totally different chemistry and are much safer. If overcharged they will NOT explode.

silverbullet555 wrote:
Is LifePo different than LiPo which can have an issue with fire?

They are different. LifePo4, AKA Lithium Iron Phosphate, are much safer and I believe have a higher energy density.

StirCrazy wrote:
any info on the cells or how you built them?

Sure. I bought the cells from RJ lithium. It takes about a month for them to arrive and it is nerve wracking waiting for them. I bought the BMS(which is a mandatory component) from Overkill Solar You can find him on Amazon and reddit, let google lead the way to these resources.

As far as assembly is concerned, I read a lot on diysolarforum.com and watched a bunch of Will Prowse videos on youtube.

One thing I would do differently if I could is bite the bullet and build a 24 volt battery instead of a 12 volt battery, mainly for big inverter loads(microwave).

As it stands I think the MW situation will still be OK once I get an inverter installed.

When I installed my Lifeline batteries I had to remove the battery tray in order to fit them in the battery compartment and the wires were a pain in the ass to deal with. Since I'm using less space in the compartment for the LFPs I put all of the load/charging leads on posts at the rear of the compartment and then connected them to posts in the front for the battery to connect to. I also added a shunt for a battery monitor so I can get an accurate assessment of my state of charge. A voltage gauge just won't cut it since the cells hang out at 3.3v most of the time.

When I have some more time I'll write up a post with the steps I took, the tools I needed and the pictures I took.

I spent a little more than I would for a single 100ah battle born but I've got 271ah and excellent monitoring and it wasn't that hard to do. Patience and planning is key.

Is LifePo different than LiPo which can have an issue with fire?

any info on the cells or how you built them?