Repurposing EV battery for home use
Discussion
I’m in the process of designing a house for client, we have been discussing incorporating energy efficient aspects into the design and one of the elements that came up was the potential of installing a battery bank to store the solar energy. I was just wondering if anyone on here has had any direct experience with taking a reclaimed EV battery and installing it as domestic storage? I’ve tried the obvious Google search, but came up short. I remember reading on one of the posts here about someone installing a Nissan Leaf battery, but now can’t find the post.
If anyone can point me in the direction of the company that is doing this sort of thing that would be appreciated.
If anyone can point me in the direction of the company that is doing this sort of thing that would be appreciated.
You'd have quite a lot of work to consider. You'd need a BMS, some sort of inverter which talks the right language to the BMS etc. And that's for AC. If you're doing it DC then you need to talk the right language to any fitted inverter. You'd also have fun with thermals, and how you heat/cool them.
Most off the using "old batteries" stuff I've seen has been plonked on racking in a shed, and homebrew wiring, but people who knew a lot about that sort of thing.
And once you've done this, how to do intent supporting it? I'd not want a house with some homebrew battery in because when it goes wrong, there's no one about who knows how it all works etc.
Most off the using "old batteries" stuff I've seen has been plonked on racking in a shed, and homebrew wiring, but people who knew a lot about that sort of thing.
And once you've done this, how to do intent supporting it? I'd not want a house with some homebrew battery in because when it goes wrong, there's no one about who knows how it all works etc.
Whats the end goal? Is it as a backup?
Don't forget charing is not the most efficient use of electricity. And it would be the wrong voltage to run much in a house unless you run through an inverter, but that again is a less efficient way of using power.
Li-ion batteries typically have a cycle life of around 500 cycles. Although it depends on the exact cells being used. For long term storage they should also be stored with a resting voltage of approx 3.75v per cell, not fully charged. Keeping them fully charged will reduce their cycle life.
I also wonder if you'd be hit with any sort of additional fire risk hazards too, not sure if building regs cover this or not. Even if not, the real world risks of a battery fire would exist. And they aren't the sort of thing you can put out with water and a hose.
Don't forget charing is not the most efficient use of electricity. And it would be the wrong voltage to run much in a house unless you run through an inverter, but that again is a less efficient way of using power.
Li-ion batteries typically have a cycle life of around 500 cycles. Although it depends on the exact cells being used. For long term storage they should also be stored with a resting voltage of approx 3.75v per cell, not fully charged. Keeping them fully charged will reduce their cycle life.
I also wonder if you'd be hit with any sort of additional fire risk hazards too, not sure if building regs cover this or not. Even if not, the real world risks of a battery fire would exist. And they aren't the sort of thing you can put out with water and a hose.
JetskiJezz said:
I’m in the process of designing a house for client, we have been discussing incorporating energy efficient aspects into the design and one of the elements that came up was the potential of installing a battery bank to store the solar energy. I was just wondering if anyone on here has had any direct experience with taking a reclaimed EV battery and installing it as domestic storage? I’ve tried the obvious Google search, but came up short. I remember reading on one of the posts here about someone installing a Nissan Leaf battery, but now can’t find the post.
If anyone can point me in the direction of the company that is doing this sort of thing that would be appreciated.
Probably not quite what you are looking for, but Jag were doing this last year. Not sure if it ever went beyond the proof of concept stage though...If anyone can point me in the direction of the company that is doing this sort of thing that would be appreciated.
https://media.jaguar.com/news/2022/03/second-life-...
From what I've seen, people are asking a lot of money for 'used' Leaf batteries.
There's not that many about and a lot of people wanting them for a) crackpot projects and b) putting in Leaves with even more knackered batteries.
The electronic you need (BMS, Charger, Invereter) are not trivial..
There's not that many about and a lot of people wanting them for a) crackpot projects and b) putting in Leaves with even more knackered batteries.
The electronic you need (BMS, Charger, Invereter) are not trivial..
300bhp/ton said:
Don't forget charing is not the most efficient use of electricity. And it would be the wrong voltage to run much in a house unless you run through an inverter, but that again is a less efficient way of using power.
Wow, now you are actually giving advice about battery systems. That's quite the turnaround in a few days.
So tell me, what is the typical round-trip efficiency of a commercial solar storage battery system?
GT9 said:
Wow, now you are actually giving advice about battery systems.
That's quite the turnaround in a few days.
So tell me, what is the typical round-trip efficiency of a commercial solar storage battery system?
I have nothing to prove to you. Go bark up someone else's leg if it bothers you so much.That's quite the turnaround in a few days.
So tell me, what is the typical round-trip efficiency of a commercial solar storage battery system?
Thanks guys for all the replies, I didn’t expect this many comments this quickly but all very much appreciated.
I should have mentioned is that I’m looking for something like the Tesla Power Wall and just wondered if there was an alternative product.
I’m not looking for some home-made system, I guessed I had thought there might be a company who was manufacturing a product that was “plug and play" but made by reusing E/V batteries to therefore be more environmentally friendly.
The reason for going down this route was to try and reduce purchase electric cost as much as possible within reasonable restrictions. Given the replies I don’t think any home-made system would be reasonable in this case. The Jaguar article is the sort of thing I was thinking of, but clearly it’s all a bit too “new” to have evolved far enough for any user or in one package.
I have absolutely no technical knowledge of this world other than only a couple of EV’s, hence asking the question in the first place. I really was looking for a one-stop simple solution and from the sound of things it looks like it’s a tesla power wall, or a much smaller home battery system or nothing.
Once again thanks for the replies, it doesn’t sound like what I’m looking for is possible unless I stick with the Tesla product.
I should have mentioned is that I’m looking for something like the Tesla Power Wall and just wondered if there was an alternative product.
I’m not looking for some home-made system, I guessed I had thought there might be a company who was manufacturing a product that was “plug and play" but made by reusing E/V batteries to therefore be more environmentally friendly.
The reason for going down this route was to try and reduce purchase electric cost as much as possible within reasonable restrictions. Given the replies I don’t think any home-made system would be reasonable in this case. The Jaguar article is the sort of thing I was thinking of, but clearly it’s all a bit too “new” to have evolved far enough for any user or in one package.
I have absolutely no technical knowledge of this world other than only a couple of EV’s, hence asking the question in the first place. I really was looking for a one-stop simple solution and from the sound of things it looks like it’s a tesla power wall, or a much smaller home battery system or nothing.
Once again thanks for the replies, it doesn’t sound like what I’m looking for is possible unless I stick with the Tesla product.
This is my local company and I recommend them.
They have home battery options beside Tesla power wall, see here:
https://www.solarsense-uk.com/residentials/solar-b...
They have home battery options beside Tesla power wall, see here:
https://www.solarsense-uk.com/residentials/solar-b...
300bhp/ton said:
GT9 said:
Wow, now you are actually giving advice about battery systems.
That's quite the turnaround in a few days.
So tell me, what is the typical round-trip efficiency of a commercial solar storage battery system?
I have nothing to prove to you. Go bark up someone else's leg if it bothers you so much.That's quite the turnaround in a few days.
So tell me, what is the typical round-trip efficiency of a commercial solar storage battery system?
Please take this as well-meaning, but you should not be giving anyone advice about electrical systems, especially safety!
I'm no expert so can't comment on any of it really, apart from provide a little anecdotal experience...
We had home solar installed and I was educated that over a certain size I would need planning permission. We stopped just under and had a 6kwh battery installed from Growatt. All great in the summer, but you tend not to use as much electricity then when my system on a very sunny height of summer day can generate maybe 27kwh. But winter when you need it more even on a sunnyish day I generate maybe 6kwh just enough to fill the battery, sadly there aren't always sunny days.
There was a bit of a dawn of realisation at how little 6kwh is in terms of running things...
Don't get me wrong really happy with the savings I have realised from the solar/battery storage and I think I was lucky with where it worked out but the installer really wasn't giving a solution just the biggest at least effort they could flog. In all reality OP if you are designing a house, there is a "right size" for the solar and storage and I'd say thats more useful to get right than how many used car batteries can I recycle from a sustainability green credits perspective (especially if you have to spend more money doing it just to say you have)
We had home solar installed and I was educated that over a certain size I would need planning permission. We stopped just under and had a 6kwh battery installed from Growatt. All great in the summer, but you tend not to use as much electricity then when my system on a very sunny height of summer day can generate maybe 27kwh. But winter when you need it more even on a sunnyish day I generate maybe 6kwh just enough to fill the battery, sadly there aren't always sunny days.
There was a bit of a dawn of realisation at how little 6kwh is in terms of running things...
Don't get me wrong really happy with the savings I have realised from the solar/battery storage and I think I was lucky with where it worked out but the installer really wasn't giving a solution just the biggest at least effort they could flog. In all reality OP if you are designing a house, there is a "right size" for the solar and storage and I'd say thats more useful to get right than how many used car batteries can I recycle from a sustainability green credits perspective (especially if you have to spend more money doing it just to say you have)
Some years back I was doing some work with one of the large FM companies, they had a deal to buy Nissan Leaf batteries after they fall outside whatever performance criteria that they have, and use them in building services applications, so it can be done and sounds quite sensible, although I have no idea what is required to collect them and it was being done on quite a large scale.
There was a company using old Leaf batteries that I looked at a good few years ago (probably after watching a Fully Charged video that mentioned them) but the cost of their solution was even higher than a Tesla powerwall was at the time. Really nutty pricing
Haven’t seen any serious mention of anything similar since. Am just in process of getting battery and solar at the moment and the favoured battery make is Pylontech
Haven’t seen any serious mention of anything similar since. Am just in process of getting battery and solar at the moment and the favoured battery make is Pylontech
I think if you did use cells dragged out of a bent Leaf the ideal place for installation together with an aliexpress BMS would be as far away as possible from habitable areas of your home.
Garage, outbuilding, Nissan hut (see watt I did there?) would be good locations.
Just google off grid storage - there are loads of better options. Also google payback times - solar makes more sense now but batteries possibly not.
Garage, outbuilding, Nissan hut (see watt I did there?) would be good locations.
Just google off grid storage - there are loads of better options. Also google payback times - solar makes more sense now but batteries possibly not.
Moonpie21 said:
I'm no expert so can't comment on any of it really, apart from provide a little anecdotal experience...
We had home solar installed and I was educated that over a certain size I would need planning permission. We stopped just under and had a 6kwh battery installed from Growatt. All great in the summer, but you tend not to use as much electricity then when my system on a very sunny height of summer day can generate maybe 27kwh. But winter when you need it more even on a sunnyish day I generate maybe 6kwh just enough to fill the battery, sadly there aren't always sunny days.
There was a bit of a dawn of realisation at how little 6kwh is in terms of running things...
Don't get me wrong really happy with the savings I have realised from the solar/battery storage and I think I was lucky with where it worked out but the installer really wasn't giving a solution just the biggest at least effort they could flog. In all reality OP if you are designing a house, there is a "right size" for the solar and storage and I'd say that's more useful to get right than how many used car batteries can I recycle from a sustainability green credits perspective (especially if you have to spend more money doing it just to say you have)
Do you not charge it up overnight on a cheap tariff? We install home batteries and that's the way they work (without solar). You can charge up at 10p per kW and use that for most/all of the day instead of paying a daytime rate of 50p per kW (guide prices for this example).We had home solar installed and I was educated that over a certain size I would need planning permission. We stopped just under and had a 6kwh battery installed from Growatt. All great in the summer, but you tend not to use as much electricity then when my system on a very sunny height of summer day can generate maybe 27kwh. But winter when you need it more even on a sunnyish day I generate maybe 6kwh just enough to fill the battery, sadly there aren't always sunny days.
There was a bit of a dawn of realisation at how little 6kwh is in terms of running things...
Don't get me wrong really happy with the savings I have realised from the solar/battery storage and I think I was lucky with where it worked out but the installer really wasn't giving a solution just the biggest at least effort they could flog. In all reality OP if you are designing a house, there is a "right size" for the solar and storage and I'd say that's more useful to get right than how many used car batteries can I recycle from a sustainability green credits perspective (especially if you have to spend more money doing it just to say you have)
An average house uses around 10kW a day but some of our customers use way more than that.
Batteries are (simplified here) 5kW or 10kW. If you need more you just connect them together.
OP, there are load of alternatives to the Tesla Powerwall too. The Powerwall is fine but a bit pricey, check out Puredrive and Givenergy.
Personally, I believe batteries will get a lot cheaper.
Factory price of cells is in the $120/kWh area, which makes 'retail' systems look bonkers expensive.
People have bought cells from China and built their own systems.
You can build a lead-acid system for maybe £150/kWh.
So, I would look to make it easy to retrofit batteries later, or maybe just start with modest capacity.
Regarding panels, they are down to the 50p per watt area now.
I would be covering the whole roof with panels and having some facing E, S and W. Or some more subtle optimum to get a long day's charging.
If you can't use or even export all the power it matters not.
Sometimes the value of it is more about the number of hours you make enough power, not peak power.
It's expensive to retrofit panels.
The way things are going I'd probably be designing in a soundproof diesel generator pit or a steam engine....
Factory price of cells is in the $120/kWh area, which makes 'retail' systems look bonkers expensive.
People have bought cells from China and built their own systems.
You can build a lead-acid system for maybe £150/kWh.
So, I would look to make it easy to retrofit batteries later, or maybe just start with modest capacity.
Regarding panels, they are down to the 50p per watt area now.
I would be covering the whole roof with panels and having some facing E, S and W. Or some more subtle optimum to get a long day's charging.
If you can't use or even export all the power it matters not.
Sometimes the value of it is more about the number of hours you make enough power, not peak power.
It's expensive to retrofit panels.
The way things are going I'd probably be designing in a soundproof diesel generator pit or a steam engine....
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