@mattengineer 80% dod preserves the battery, so you'll see it recommended a lot of places. Honestly I don't have any issues with my Sofar pylontech setup. It's worked flawlessly for 3 years solid.

Currently I'm on the hunt for an inverter that'll do 100amps (5kw) charging/discharging. That'll give me 8.3kw peak and mean I can charge 20 useable KW over 4hrs on octopus go along side my 14kwh battery at 3kw from my Sofar (11.2kwh useable at 80% dod)

@balalto Can you give an idea of the kind of cost of your battery ? Do you think there's any point getting battery without PV or is that just daft ?

@heat-pump-newbie I've got pylontech 3000s and 2000s. You can find them easily enough on eBay if you want up to date prices. However for my next batteries in going with Seplos ones. Lifepo4 batteries are all the same chemistry, it's only really the battery management system (BMS) that matters. They are also super stable so no chance of "thermal runaway" aka fire.

Seplos are really well priced, but ship in from China. So I'll have to order them when ready. Ideally I'll order with others as they give a really good volume discount. 

My real question is the inverter as I want 100 amps (5kw @ 50v). That's taking a bit more research.

@heat-pump-newbie, personally I’ve always struggled with battery ROI. To answer your question you don’t need PV for batteries to work; if you have a variable tariff and you charge the batteries from 1-5am or whenever the tariffs are lowest, that’ll save you money.

Posted by: @editor

@heat-pump-newbie, personally I’ve always struggled with battery ROI. To answer your question you don’t need PV for batteries to work; if you have a variable tariff and you charge the batteries from 1-5am or whenever the tariffs are lowest, that’ll save you money.

I agree the ROI is important. I have looked at batteries especially since the recent price increases. I reckon I would need at least a 12kw setup. To make this viable the cost would need to be in the region of £5000 and to have cheap off-peak electricity available. On a rough estimate, I would probably save in the region of £500 a year. On a reality check, the batteries will probably be a lot dearer making the ROI unviable. Much of what is happening is government policy from the untenable price increases to an energy grid that is not fit for purpose. Are we going to see changes in policy? Unlikely I think we will get massive loans to the industry for short-term gains which will increase prices further over the long term.  Maybe the government should be investing in households to reduce energy use rather than looking to "subsidies" the industry. Maybe then we will get cheaper batteries:-) Can you imagine investing 9£bn in household batteries how much resilence would be built into the grid?

@batalto Hi, early days for me but I might be looking for some batteries too. If you’re looking for people to join an order let me know.

Andy

@prjohn you can get 6.9kwh for $1900 USD before volume discount from Seplos. The trick is to get the unit number up. If you order 12 or more it's basically half that price. I've done quite a bit of research into batteries and they are all basically the same Lifepo4 cells in a different case.

Posted by: @prjohn

Posted by: @editor

@heat-pump-newbie, personally I’ve always struggled with battery ROI. To answer your question you don’t need PV for batteries to work; if you have a variable tariff and you charge the batteries from 1-5am or whenever the tariffs are lowest, that’ll save you money.

I agree the ROI is important. I have looked at batteries especially since the recent price increases. I reckon I would need at least a 12kw setup. To make this viable the cost would need to be in the region of £5000 and to have cheap off-peak electricity available. On a rough estimate, I would probably save in the region of £500 a year. On a reality check, the batteries will probably be a lot dearer making the ROI unviable. Much of what is happening is government policy from the untenable price increases to an energy grid that is not fit for purpose. Are we going to see changes in policy? Unlikely I think we will get massive loans to the industry for short-term gains which will increase prices further over the long term.  Maybe the government should be investing in households to reduce energy use rather than looking to "subsidies" the industry. Maybe then we will get cheaper batteries:-) Can you imagine investing 9£bn in household batteries how much resilence would be built into the grid?

For quite some time I have been trying to convince anyone who would listen, that the primary objective should be to reduce energy consumption by improved insulation and draft proofing, which in most cases would be a much better ROI than any other measure. There are just so many benefits to be gained. Reduced energy consumption would not only mean lower bills for the consumer, it would also mean lower gas imports, which would be better for the balance of payments, and may also help to reduce gas prices. Lower electricity consumption would mean less reliance on fossil fuel generation, the need for less renewable generation, and also reduce the requirement to improve the electricity distribution networks to supply increasing demand. If you don't need the power in the first place, it does not need to be generated, or transported and paid for.

From recent discussions that I have had with a close friend, it would appear that the powers that be at National Grid, seem to think that it would be a good idea to go back to the days when each community, be it a city, town or village, had their own generating capacity, so would not need a National Grid. Whilst I agree that electricity generation close to the consumer is to be preferred, I can see a slight flaw in their thinking of getting rid of the National Grid. How do you get the power being generated by all those wind farms in the North Sea to the consumers, which as far as I am aware are not in the North Sea? The last time I checked, electricity did not transport very well in buckets. 🙄 

Cornwall Insight's latest is the cap will rise 51%. 😮 

@kev-m, that’s scary. I’m genuinely concerned about the rising cost of electricity. Running a heat pump is electricity intensive and it’s not the same as just turning off a light bulb to keep costs down. Even when they’re running efficiently, they draw a lot of power. 

Posted by: @kev-m

Cornwall Insight's latest is the cap will rise 51%. 😮 

And the October cap is estimated to be another 20% on top of the April cap if there is no intervention. 

Another supplier gone. 

Together and Bristol Energy 

https://www.independent.co.uk/news/business/together-energy-collapse-gas-prices-b1995505.html