# Would this homebrew battery storage solution work out?

**URL:** <https://community.openenergymonitor.org/t/would-this-homebrew-battery-storage-solution-work-out/20759>\
**Category:** Sustainable Energy\
**Created:** [27 June 2022 14:35 UTC](https://community.openenergymonitor.org/t/would-this-homebrew-battery-storage-solution-work-out/20759 "2022-06-27T14:35:29Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Radian](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/radian/32/21099_2.png) [@Radian](https://community.openenergymonitor.org/u/Radian)\
**Post date:** [27 June 2022 14:35 UTC](https://community.openenergymonitor.org/t/would-this-homebrew-battery-storage-solution-work-out/20759/1 "2022-06-27T14:35:29Z")

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I’ve been looking at some small AC coupled 5kWh battery solutions and the cost is prohibitive given that, from what I see, they need pairing with particular inverters so I’d be buying a new system: charger/battery/inverter to use with my existing PV modules.

On the other hand, a pair of 24V 100Ah LiFePO4’s can be had for around £1600 and I already have an unused 3.6kW MPPT inverter input. The batteries each come with a 24V 15A mains charger so would fill the batteries in around 7 hours. They’re isolated so they would float onto the two batteries, and the batteries would each connect to a boost converter (24V@30A in for 60V@10A out) with the output of those wired in series to meet the minimum starting voltage of the inverter.

So, around 1200W for 3 Hours or so, to extend the self generated day a bit. All in price ~£1640

The only issue I can see is when the built-in BMS cuts out for undervoltage protection, one would trip before the other. Where would this leave the other battery?