We'd like to remind Forumites to please avoid political debate on the Forum... Read More »
📨 Have you signed up to the Forum's new Email Digest yet? Get a selection of trending threads sent straight to your inbox daily, weekly or monthly!
Best value battery system?
Options

Spies
Posts: 2,267 Forumite


I currently have a solax 3.6kw solar inverter, what's the best approach to add a battery to the system?
Replace the inverter with hybrid or have an AC connected system?
Is fogstar the best value at the moment, which inverter is preferred and do they have any wireless CTs?
Replace the inverter with hybrid or have an AC connected system?
Is fogstar the best value at the moment, which inverter is preferred and do they have any wireless CTs?
4.29kWp Solar system, 45/55 South/West split in cloudy rainy Cumbria.
0
Comments
-
The best value I know of is the Seplos battery sold by Fogstar, 16.1 kWh for £1749.99. Or a little less if you buy it as a kit and assemble it yourself. It's sold by Fogstar but not to be confused with their own Fogstar branded battery which is a bit more expensive but still very good value.Solar install June 2022, Bath
4.8 kW array, Growatt SPH5000 inverter, 1x Seplos Mason 280L V3 battery 15.2 kWh.
SSW roof. ~22° pitch, BISF house. 12 x 400W Hyundai panels0 -
"Value" is a tricky proposition, as there's more to it than price-per-kWh.Some people will say that the best value is from a battery that's compaltible with Intelligent Octopus Flux, which means Tesla / GivEnergy / SolarEdge / Enphase.Others might say that, if you can buy the same battery capacity as a PW3 from Fogstar plus a hybrid or AC-coupled inverter and save £5k, it'ls going to take a lot of tariff-specific gains to make up for the extra outlay.You'll find folk in both camps here, gently ribbing each other.N. Hampshire, he/him. Octopus Intelligent Go elec & Tracker gas / Vodafone BB / iD mobile. Ripple Kirk Hill member.
2.72kWp PV facing SSW installed Jan 2012. 11 x 247w panels, 3.6kw inverter. 34 MWh generated, long-term average 2.6 Os.Not exactly back from my break, but dipping in and out of the forum.Ofgem cap table, Ofgem cap explainer. Economy 7 cap explainer. Gas vs E7 vs peak elec heating costs, Best kettle!1 -
QrizB said:"Value" is a tricky proposition, as there's more to it than price-per-kWh.Some people will say that the best value is from a battery that's compaltible with Intelligent Octopus Flux, which means Tesla / GivEnergy / SolarEdge / Enphase.Others might say that, if you can buy the same battery capacity as a PW3 from Fogstar plus a hybrid or AC-coupled inverter and save £5k, it'ls going to take a lot of tariff-specific gains to make up for the extra outlay.You'll find folk in both camps here, gently ribbing each other.Solar install June 2022, Bath
4.8 kW array, Growatt SPH5000 inverter, 1x Seplos Mason 280L V3 battery 15.2 kWh.
SSW roof. ~22° pitch, BISF house. 12 x 400W Hyundai panels0 -
Fogstar recently had the 15.5kWh batteries at £2000, again, but I think they're sold out. They were that price last Black Friday, if you can wait until the next BF.
0 -
QrizB said:"Value" is a tricky proposition, as there's more to it than price-per-kWh.Some people will say that the best value is from a battery that's compaltible with Intelligent Octopus Flux, which means Tesla / GivEnergy / SolarEdge / Enphase.Others might say that, if you can buy the same battery capacity as a PW3 from Fogstar plus a hybrid or AC-coupled inverter and save £5k, it'ls going to take a lot of tariff-specific gains to make up for the extra outlay.You'll find folk in both camps here, gently ribbing each other.For example, I wouldn't want to stick a Fogstar outside. Besides the IP weatherproof ratings, there's also the issue of thermal management of the cells. No point having a huge battery that won't charge in winter when the weather drops below zero. If installing outside, this would be my primary concern.1
-
NedS said:QrizB said:"Value" is a tricky proposition, as there's more to it than price-per-kWh.Some people will say that the best value is from a battery that's compaltible with Intelligent Octopus Flux, which means Tesla / GivEnergy / SolarEdge / Enphase.Others might say that, if you can buy the same battery capacity as a PW3 from Fogstar plus a hybrid or AC-coupled inverter and save £5k, it'ls going to take a lot of tariff-specific gains to make up for the extra outlay.You'll find folk in both camps here, gently ribbing each other.For example, I wouldn't want to stick a Fogstar outside. Besides the IP weatherproof ratings, there's also the issue of thermal management of the cells. No point having a huge battery that won't charge in winter when the weather drops below zero. If installing outside, this would be my primary concern.1
-
Netexporter said:NedS said:QrizB said:"Value" is a tricky proposition, as there's more to it than price-per-kWh.Some people will say that the best value is from a battery that's compaltible with Intelligent Octopus Flux, which means Tesla / GivEnergy / SolarEdge / Enphase.Others might say that, if you can buy the same battery capacity as a PW3 from Fogstar plus a hybrid or AC-coupled inverter and save £5k, it'ls going to take a lot of tariff-specific gains to make up for the extra outlay.You'll find folk in both camps here, gently ribbing each other.For example, I wouldn't want to stick a Fogstar outside. Besides the IP weatherproof ratings, there's also the issue of thermal management of the cells. No point having a huge battery that won't charge in winter when the weather drops below zero. If installing outside, this would be my primary concern.
There was no heating in the Seplos Mason kit that I built.N. Hampshire, he/him. Octopus Intelligent Go elec & Tracker gas / Vodafone BB / iD mobile. Ripple Kirk Hill member.
2.72kWp PV facing SSW installed Jan 2012. 11 x 247w panels, 3.6kw inverter. 34 MWh generated, long-term average 2.6 Os.Not exactly back from my break, but dipping in and out of the forum.Ofgem cap table, Ofgem cap explainer. Economy 7 cap explainer. Gas vs E7 vs peak elec heating costs, Best kettle!0 -
QrizB said:Netexporter said:NedS said:QrizB said:"Value" is a tricky proposition, as there's more to it than price-per-kWh.Some people will say that the best value is from a battery that's compaltible with Intelligent Octopus Flux, which means Tesla / GivEnergy / SolarEdge / Enphase.Others might say that, if you can buy the same battery capacity as a PW3 from Fogstar plus a hybrid or AC-coupled inverter and save £5k, it'ls going to take a lot of tariff-specific gains to make up for the extra outlay.You'll find folk in both camps here, gently ribbing each other.For example, I wouldn't want to stick a Fogstar outside. Besides the IP weatherproof ratings, there's also the issue of thermal management of the cells. No point having a huge battery that won't charge in winter when the weather drops below zero. If installing outside, this would be my primary concern.
There was no heating in the Seplos Mason kit that I built.Solar install June 2022, Bath
4.8 kW array, Growatt SPH5000 inverter, 1x Seplos Mason 280L V3 battery 15.2 kWh.
SSW roof. ~22° pitch, BISF house. 12 x 400W Hyundai panels2 -
I would likely need a qualified electrician to install as I don't have a dedicated circuit I could use, unless I swapped my solar inverter for a hybrid, what would be a good hybrid inverter with local access that would support the fogstar battery?4.29kWp Solar system, 45/55 South/West split in cloudy rainy Cumbria.0
-
I'm going to use an 8kW Sunsynk (DNO permitting) so I can fill 2 batteries easily in a 4 hour cheap window. Also it has the facility for islanding in the event of a power cut (which are fairly frequent here).1
Confirm your email address to Create Threads and Reply

Categories
- All Categories
- 351.1K Banking & Borrowing
- 253.1K Reduce Debt & Boost Income
- 453.6K Spending & Discounts
- 244.1K Work, Benefits & Business
- 599K Mortgages, Homes & Bills
- 177K Life & Family
- 257.4K Travel & Transport
- 1.5M Hobbies & Leisure
- 16.1K Discuss & Feedback
- 37.6K Read-Only Boards