somewhere on their site was something on warranties and guarantees.. havent check them out in detail yet (will have to wait this weekend) but a friend remarked they looked like a very good alternative ..
These guys do https://www.freedomwon.co.za/advantages-of-lifepo4-batteries/ and you can find prices here https://thepowerstore.co.za/products/lite-home-10kwh-7kwh
I was looking for something similar to the powerwall and found them
Item Wanted : Battery and power brick for the following laptop : Asus N56VM 15.6" Notebook Computer (N56VM-S4060X)
Price: need some quotes