[kiliantics]

I built a storage system with these, which are almost down to $300/kWh now:

https://www.currentconnected.com/product/sk48v100-48v-server...

Of course you will need a charge controller and some other components which will add to the cost.

[aaronax]

What's the go to rack mount inverter charger to go along with that? Asking for a friend...who only needs about 800 watts of capacity to act as the certified hacker version of a UPS. I've only done Victron stuff in the past, and those are not rackmount nor is there a 48V in 120V out model of less than 3000VA capacity.