I have built a couple of home energy storage projects. Both with cheap Chinese hybrid inverters (which I find work incredibly well for the measley cost) and ex EV batteries. I have one at home in the cupboard using MG 15s6p batteries 16.6kWh and a 5kW inverter but we are not allowed solar because of planning so I just use it to avoid peak rate, special high price days here in France, and all the mini power cuts common here. The other is a 24kWh ENV-200 battery split down to 14s6p with 3kW solar and a 3.2kW hybrid inverter which powers my workshop.
I don't use BMS. The inverter regulates top and bottom charge limit just as reliably (or not) as a BMS. And I have a Bluetooth active balancer on each system that keeps the cells in check. Obviously this leaves risk of a cell over charging in the event of the balancer not being able to keeps them even. But my experience ove the last three years with these systems has been that the cells are incredibly well matched by the EV manufacturers and I see virtually zero need even for the balancer. I just check in on them once a week to be sure nothing is going wonky. I'm.sure people with take issue with that. But whilst I'm allowed to cross the road by myself I figure I can make other grown up decisions also
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Anyhow, that is not why I am here.
I was wondering if anybody has considered, or even got anywhere with the idea of using the Leaf motor stack as a gravity battery driver. What I mean is using it to pull something heavy up and down in order to convert electricity to gravitational potential energy and then use regen to convert back again? Anybody? Any comments? Friendly
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I have a 'spare' 2017 Leaf fully functional albeit with a bent chassis and no doors, windows, seats, linings, etc. And I have a hill. 100m tall 180m wide. I've done some light math, and can't see any reason not to. I'll leave it there for the moment and see if this gets any interest.
I should probably just stress that whilst I have a dream, I am wholly incapable of making it into a reality!! So I would be looking for collaborators.
Thanks for your time, I look forward to whatever it brings
Tom.