That all sounds very good but you obviously have far more specialist knowledge that I do. I have had someone give me a quote for solar with battery storage but just felt uneasy with how they were trying to push me to sign up there and then, but two things that have stuck in my mind about their visit was how they pushed how good battery storage would be in our circumstances and how much different batteries could vary in quality and potential life. They also tried to baffle me with weights of different batteries and how crucial it could be in relation to size, especially as the installation would mostly be going into the loft, so I was just curious what sort of weight a 15kwh battery would be.
The Givenergy All in One 13.5kWh weighs 173kg
The Fogstar Energy 30kWh 48V weighs 173kg but is more than double the capacity.
This does not mean the Givenergy is better, just because it is heavier. The design of the unit and casing plays a part.
Both have the same battery chemistry of LFP (LiFePO4) meaning each battery cell in both the Fogstar & Givenergy are basically equal in weight and energy density.
Givenergy is a subsidiary Shenzhen Givenergy Technology Co., Ltd. Specifically, the company operates a manufacturing facility in Shenzhen, China and the units are put together in the UK and other countries.
Fogstar is a British company, who deal in Solar, other LiFePO4 and Vape batteries. The company some batteries under its own name but, that are made by other companies and are open about this. For their own branded solar batteries they use batteries produced by EVlithium, particularly EVE LF100LA and LF304 depending on the solar battery you want. EVlithium are located Zaozhuang, Shandong province China.
https://www.evlithium.com/html/about.html
So the battery manufactures are China v China. Fogstar use a UK designed heated system to keep the batteries warm and enable optinum charging in colder weather. They also you use a Pace Battery Management System, which is considered gold standard. I’m not sure if Givenergy have battery heating or the BMS used but, it is ip65 rated for outdoors, where as Fogstars rack system isn’t but, they do have another designed system cheaper still for the same kWh.
I’m a sparky along with having MCS certifation and lets say I’m a Growatt certified installer and you invited me to give you a quote, you would quoted/pushed for a Growatt solar battery and told its the best thing since sliced bread. Is it better actually better than the rest, when they are all based on LFP/LiFePO4 and typically each cell has the same weight and energy density. There is alot more in what makes a solar battery apart from the battery itself, like has it got a good quality BMS system and what other important features does it have along with useability, size and suitability for location of fitment.