House batteries
Discussion
I was looking at getting a battery for the house, charge it at night (EV tariff), use it during the day. Potentially save around £600 a year with a 10kwh (usable) battery.
Not cheap to buy though, unless you go for something "unbranded". Tesla etc. seem to cost £700+ per kwh usable, installed.
I've just ordered my first EV, and Kia EV3. Comes with an 80kwh battery.
I went for the top trim level at £43k, but the base model with the same battery is £36k.
Works out at less than £500 per kwh, and you get a complete car thrown in too!
Why are branded house batteries so expensive?
My car is supplied with a vehicle to load adaptor for the charge port, as well as a 13A socket inside the car. It looks like it's also capable of vehicle to grid and vehicle to home, but there are no UK-approved chargers/control boxes that can utilise the facility yet.
I wonder when these will be available?
Not cheap to buy though, unless you go for something "unbranded". Tesla etc. seem to cost £700+ per kwh usable, installed.
I've just ordered my first EV, and Kia EV3. Comes with an 80kwh battery.
I went for the top trim level at £43k, but the base model with the same battery is £36k.
Works out at less than £500 per kwh, and you get a complete car thrown in too!
Why are branded house batteries so expensive?
My car is supplied with a vehicle to load adaptor for the charge port, as well as a 13A socket inside the car. It looks like it's also capable of vehicle to grid and vehicle to home, but there are no UK-approved chargers/control boxes that can utilise the facility yet.
I wonder when these will be available?
clockworks said:
I was looking at getting a battery for the house, charge it at night (EV tariff), use it during the day. Potentially save around £600 a year with a 10kwh (usable) battery.
Not cheap to buy though, unless you go for something "unbranded". Tesla etc. seem to cost £700+ per kwh usable, installed.
I've just ordered my first EV, and Kia EV3. Comes with an 80kwh battery.
I went for the top trim level at £43k, but the base model with the same battery is £36k.
Works out at less than £500 per kwh, and you get a complete car thrown in too!
Why are branded house batteries so expensive?
My car is supplied with a vehicle to load adaptor for the charge port, as well as a 13A socket inside the car. It looks like it's also capable of vehicle to grid and vehicle to home, but there are no UK-approved chargers/control boxes that can utilise the facility yet.
I wonder when these will be available?
I installed/built a storage system earlier this year. Prices for 'branded' (EVE) cells was in the order of £100 per kWh and that included shipping which was some hundreds of pounds. Sure there are other components ro the system but the 'raw' storage cost isn't too bad.Not cheap to buy though, unless you go for something "unbranded". Tesla etc. seem to cost £700+ per kwh usable, installed.
I've just ordered my first EV, and Kia EV3. Comes with an 80kwh battery.
I went for the top trim level at £43k, but the base model with the same battery is £36k.
Works out at less than £500 per kwh, and you get a complete car thrown in too!
Why are branded house batteries so expensive?
My car is supplied with a vehicle to load adaptor for the charge port, as well as a 13A socket inside the car. It looks like it's also capable of vehicle to grid and vehicle to home, but there are no UK-approved chargers/control boxes that can utilise the facility yet.
I wonder when these will be available?
I made the mistake of having a bit less storage than would be optimal - having close on you daily usage seems to be a good target.
There are some technical considerations, mainly to do with the rate of energy flow around the system too. The simple case where it is cheap rate/normal rate is easier to design for.
I am pleased with my system, savings vary (using Agile at present), but some times daily cost is zero - and I use around 24kWh per day.
Cell prices keep coming down.
https://www.fogstar.co.uk/collections/lifepo4
The inverters and control electronics are not trivial.
But getting cheaper as the market expands.
I know a few people who've put LIFePO4 systems on yachts, and a few businesses which have pretty serious systems for solar and UPS purposes.
The sting in the tail though is that vast quantities of batteries are going into the grid, which is bound to affect the hour by hour price of electricity eventually.
It's not like the solar frenzy of getting your snout in the trough for 25 years of guaranteed prices.
https://www.fogstar.co.uk/collections/lifepo4
The inverters and control electronics are not trivial.
But getting cheaper as the market expands.
I know a few people who've put LIFePO4 systems on yachts, and a few businesses which have pretty serious systems for solar and UPS purposes.
The sting in the tail though is that vast quantities of batteries are going into the grid, which is bound to affect the hour by hour price of electricity eventually.
It's not like the solar frenzy of getting your snout in the trough for 25 years of guaranteed prices.
clockworks said:
Not cheap to buy though, unless you go for something "unbranded". Tesla etc. seem to cost £700+ per kwh usable, installed.
I think it was from February this year that battery installations became zero rated VAT, so if you can find an installer who doesn't charge the earth, something like this can be had for <£6k installed:https://www.solartradesales.co.uk/givenergy-all-on...
13.5kWh usable battery.
6kW inverter.
Battery backup in case of power cuts.
12yr warranty.
OutInTheShed said:
Cell prices keep coming down.
https://www.fogstar.co.uk/collections/lifepo4
The inverters and control electronics are not trivial.
But getting cheaper as the market expands.
I know a few people who've put LIFePO4 systems on yachts, and a few businesses which have pretty serious systems for solar and UPS purposes.
The sting in the tail though is that vast quantities of batteries are going into the grid, which is bound to affect the hour by hour price of electricity eventually.
It's not like the solar frenzy of getting your snout in the trough for 25 years of guaranteed prices.
I know we can't name and shame but the customer support from some suppliers mentioned in this thread is not great. My BMS broke and mainly they did not want to know putting me on to Seplos in China who then posted it back to the wrong address (wrong person and wrong country) and then washed their hands of it.https://www.fogstar.co.uk/collections/lifepo4
The inverters and control electronics are not trivial.
But getting cheaper as the market expands.
I know a few people who've put LIFePO4 systems on yachts, and a few businesses which have pretty serious systems for solar and UPS purposes.
The sting in the tail though is that vast quantities of batteries are going into the grid, which is bound to affect the hour by hour price of electricity eventually.
It's not like the solar frenzy of getting your snout in the trough for 25 years of guaranteed prices.
I've got 3x Pylontech US5000s, which can be had for £915+VAT via ITS Technologies now, although they'll offer you VAT free if you can prove you've installed them yourself. I charge overnight on the Octopus 7p IOG rate. I've recently moved to that from Agile where I'd got an average of just over 10p, so my import for the year of 5100kwh has so far cost me £492, against what would've cost £1289 on the price cap, so £797 to the good in a year.
clockworks said:
Saw an interesting post on a Facebook group.
American chap had a relatively small house battery, but could top it up using his EV's V2L cable.
Possibly not much point on a day to day basis, but very useful for power cuts.
Is this kind of setup doable in the UK?
Well, it is, with suitable kit.American chap had a relatively small house battery, but could top it up using his EV's V2L cable.
Possibly not much point on a day to day basis, but very useful for power cuts.
Is this kind of setup doable in the UK?
Off the top of my head, (some) Victron inverter/chargers have a 'generator' input. I would think it fairly easy to integrate the V2L supply in to that. It is logically going to be rectifying that V2L input, then running the inverter to provide the house supply. This then need to be capable of running in 'island mode' as the grid would have gone away in a power outage scenario.
You would need to look carefully at the current limits through the sections (KIA state their V2L adaptor is good for 3.6kW for instance).
I wouldn't have thought it worthwhile really - once you have the equipment required, a few extra kWh of batteries are not really that expensive. Too much messing around with V2L adaptors and plugging in for little gain. V2G is a different kettle of worms - but V2G equipment seems to be many k at present.
Interesting technical project all the same.
Ideally you'd want a relatively small battery powering the house, and the car battery "topping up" the house battery.
That way, the house battery would take care of peaks in demand over and above the V2L limit.
I appreciate that you'd need a pretty chunky house battery and inverter if you wanted to run an electric shower - presumably the 1C max discharge rate applies to house batteries?
Leaving aside the shower and cooker, 3.6kW should be enough for heating and lights etc
That way, the house battery would take care of peaks in demand over and above the V2L limit.
I appreciate that you'd need a pretty chunky house battery and inverter if you wanted to run an electric shower - presumably the 1C max discharge rate applies to house batteries?
Leaving aside the shower and cooker, 3.6kW should be enough for heating and lights etc
I think you should take a step back and ask what you really want and expect from all this.
If you make your house system complex, you could make it less reliable than the mains.
It's pretty hard to pin down the requirement, because most people are unlikely to get many power cuts, and most power cuts are short and not that inconvenient. So do you plan like a prepper, for 3 day outages in blizzards?
I've got a generator, but TBH I'll get through most power cuts with a book, a battery light, a gas hob and a duvet.
I've got friends with businesses where serious uninterruptable power is justified, but that takes investment, management and maintenance.
If you make your house system complex, you could make it less reliable than the mains.
It's pretty hard to pin down the requirement, because most people are unlikely to get many power cuts, and most power cuts are short and not that inconvenient. So do you plan like a prepper, for 3 day outages in blizzards?
I've got a generator, but TBH I'll get through most power cuts with a book, a battery light, a gas hob and a duvet.
I've got friends with businesses where serious uninterruptable power is justified, but that takes investment, management and maintenance.
clockworks said:
I appreciate that you'd need a pretty chunky house battery and inverter if you wanted to run an electric shower - presumably the 1C max discharge rate applies to house batteries?
Leaving aside the shower and cooker, 3.6kW should be enough for heating and lights etc
For the EVE cells I have, the 'standard' charge rate is 0.5C, 'maximum' (continuous) is 1C and short term peak (30 s max) is 2C. At the latter there are some reasonably big currents flowing, would be 560A in my case.Leaving aside the shower and cooker, 3.6kW should be enough for heating and lights etc
BUT, the battery management system - usually part of the 'battery' for a commercialy available system will have a current limit too.
As an example, mine is nominally 100A - so I am limited to pushing/pulling no more than 5kW from the batteries. Which in my case isn't an issue as the inverter is 5kW output too.
Leaving aside the off-grid/power cut scenario, the system just pulls the additional needs from the grid eg. for the 1 minute you put the kettle on, which tips the demand over what you can provide locally.
Assuming the heating mentioned above isn't electric, then 3.6kW is generally enough for all but the biggest peaks.
You are right, I do need to step back.
I was originally thinking more about long-term financial benefits, with the advantage of resilience.
We tend to get one or two power cuts a year. Normally get by with battery packs, and the woodburner for heat and making a cuppa, plus a little camping stove.
Biggest issue was no Internet ( no mobile signal here), so we've now got a battery pack with an inverter to power the router.
I think my best bet will be to run a decent extension lead into the house from the car if a power cut lasts more than a few hours. Enough to run a small oil-filled radiator and recharge the USB battery packs.
Maybe look again at V2H in a few years.
I was originally thinking more about long-term financial benefits, with the advantage of resilience.
We tend to get one or two power cuts a year. Normally get by with battery packs, and the woodburner for heat and making a cuppa, plus a little camping stove.
Biggest issue was no Internet ( no mobile signal here), so we've now got a battery pack with an inverter to power the router.
I think my best bet will be to run a decent extension lead into the house from the car if a power cut lasts more than a few hours. Enough to run a small oil-filled radiator and recharge the USB battery packs.
Maybe look again at V2H in a few years.
mrmistoffelees said:
I've got 3x Pylontech US5000s, which can be had for £915+VAT via ITS Technologies now, although they'll offer you VAT free if you can prove you've installed them yourself. I charge overnight on the Octopus 7p IOG rate. I've recently moved to that from Agile where I'd got an average of just over 10p, so my import for the year of 5100kwh has so far cost me £492, against what would've cost £1289 on the price cap, so £797 to the good in a year.
We also have 3x Pylontech US5000 batteries - over 14kWh capacity. We have a LuxPowerTek AC invertor (didn’t interfere with our solar FIT system), over 2 years in now.
We do not have backup power option - it only adds a double socket which wouldn’t power the house. If you really want “off grid” house power, you probably need the pricier Tesla option.
We do, however, average under 10p per kWh used, even though we are only on the Octopus Go cheap 4hr tariff.
Quite happy with our system.
Cost will no doubt have gone up a chunk now, but was under £6.5k when we had it done….payback within around 5 years.
Of course it isn’t all about payback, sometimes it is about doing the right thing for us & the wider use of energy in the UK - nobody rates a new kitchen on that!
Just seen this - Fogstar 15.5kWh pack for £2k, on pre-order:
https://www.fogstar.co.uk/collections/solar-batter...
https://www.fogstar.co.uk/collections/solar-batter...
I do have an inverter, a petrol generator and some random 12V stuff lying about.
In theory, it's not hard to power a router, fridge and freezer and a few lights.
Due to my boating interests, I have ability to charge phones and laptops from 12V.
Push come to shove, I can charge a spare 12V battery by running my diesel car.
You can get a fair amount resilience to power cuts quite cheaply. Maybe a 'Jackery' type power bank would save the contents of the freezer in most cases? If I lived out on the moors, then no question, I'd keep the generator serviced.
But if the power went out and it's likely to be out for 2 days or more, then I'd probably not be wanting to take much 'fuel' out of my car.
Last time I was actually inconvenienced by a power cut, we couldn't even buy lunch in some daft village, because no tills worked in the shop or pub.
In theory, it's not hard to power a router, fridge and freezer and a few lights.
Due to my boating interests, I have ability to charge phones and laptops from 12V.
Push come to shove, I can charge a spare 12V battery by running my diesel car.
You can get a fair amount resilience to power cuts quite cheaply. Maybe a 'Jackery' type power bank would save the contents of the freezer in most cases? If I lived out on the moors, then no question, I'd keep the generator serviced.
But if the power went out and it's likely to be out for 2 days or more, then I'd probably not be wanting to take much 'fuel' out of my car.
Last time I was actually inconvenienced by a power cut, we couldn't even buy lunch in some daft village, because no tills worked in the shop or pub.
Gareth79 said:
Just seen this - Fogstar 15.5kWh pack for £2k, on pre-order:
https://www.fogstar.co.uk/collections/solar-batter...
Good price for the capacity, prices certainly tumbled - I've got 6 x Pylontec US3000's (3.5kw) which cost me about £1200 each a couple of years ago.https://www.fogstar.co.uk/collections/solar-batter...
I charge overnight on GO and run entirely on battery outside the the 5 hours and my average unit price is around 9p (as you always get a little grid draw as the inverter ramps up/down)
I'm in the Victron ecosystem, which is DIY friendly - but probably not suitable if you just want a box to hang on the wall and forget about it. I've posted some videos on YT about wiring it all up and how to split your consumer unit into critical/non critical loads for grid failure scenarios.
My oil system boiler was actually installed 25 years ago (previous owner) using a 13A plug and socket in the garage. Obviously works fine, but is it compliant with the current regs?
I've had it serviced by several different people, leaving me proper certificates, and none of them have mentioned it, so I guess it was legal at the time.
I've had it serviced by several different people, leaving me proper certificates, and none of them have mentioned it, so I guess it was legal at the time.
Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff