Has anyone used an old EV battery connected to an inverter to store solar power

Forums › Home Workshop DIY › Has anyone used an old EV battery connected to an inverter to store solar power

prob

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Master Geek
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#322907 5-Oct-2025 18:37

I have been following this project which allows EV batteries to be used with many inverters.

There are lots of examples in the wiki. Suits a high voltage inverter like the Huawei Sun2000 (rebranded Entelar in NZ) I have installed.

Leaf batteries are very cheap second hand, hmmm..

https://github.com/dalathegreat/Battery-Emulator/wiki

Jase2985

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#3421821 5-Oct-2025 19:26

Not currently legal for grid tied systems, but off grid, you can pretty much do what you like.

Would love for it to be approved for grid tied stuff.

johno1234

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#3421850 5-Oct-2025 21:21

There’s a guy selling recovered Tesla car batteries on TM who mentions a guy who does home inverter gear for them.

https://www.trademe.co.nz/a/motors/car-parts-accessories/batteries-chargers/listing/5552115251

MikeFly

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#3421876 6-Oct-2025 03:43

johno1234:

There’s a guy selling recovered Tesla car batteries on TM who mentions a guy who does home inverter gear for them.

https://www.trademe.co.nz/a/motors/car-parts-accessories/batteries-chargers/listing/5552115251

The guy selling the gear mentioned in the TM (https://www.lithium-power.com.au/s/shop) ad is just selling a pre built version of the Dala project

nutbugs

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#3421987 6-Oct-2025 08:55

EVs Enhanced in Christchurch are in the process of bundling a package that will support this. Not DIY but will pass the approval requirements in theory. I specifically asked about it being able to be signed off without any regulatory issues and they assured it is all valid if installed by a registered sparky. I have a 60 odd % 30Kwhw leaf battery so am very interested in this :)

johno1234

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#3422021 6-Oct-2025 09:54

Seems like a plan such as Contact's 9pm to midnight free power could really be exploited with an EV battery. We use about 19KWh a day in winter, which could be run off a battery that can be recharged in 3 hours overnight so would not justify any solar. Their Fair Use Policy allows 200KWh per week of free power.

Is there such a thing as free power?

(That Contact plan is Mon-Fri only)

MikeFly

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#3422032 6-Oct-2025 10:24

Contact wont let you on that plan if you have solar, not sure about battery but I would assume it would be the same.

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johno1234

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#3422066 6-Oct-2025 11:18

MikeFly:

Contact wont let you on that plan if you have solar, not sure about battery but I would assume it would be the same.

It took three levels of drilling into the T&C to get to this:

"To be eligible for the Good Nights plan, you must have an eligible, and actively communicating, electricity
smart meter. Customers who have installed, or are operating a distributed generation and/or solar
system, are not eligible for this plan."

"Distributed Generation" just means exporting back to grid? If so seems like they have yet to exclude this cunning plan.

richms

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#3422077 6-Oct-2025 12:05

If you had an inverter that did not export to the grid then it is none of their business. Plenty of hybrid inverters have a generator input which will not get exported to, and that can be used from the grid to charge the battery and pass thru to the load side when you are in the free period.

Richard rich.ms