Solar panels and battery - any real world recommendations?

I guess I achieved the impossible, along with many others that have these batteries.

There is no regulation for 48v DC that I'm aware of. That said you really need to understand what you are doing, especially if setting up the BMS.
 
randal said:
www.fogstar.co.uk

Fogstar Energy 51.2V 32kWh Battery

32kWh 51.2V Fogstar Energy Battery, ideal for off-grid living, backup power, renewable energy systems and industrial energy management, this battery ensures reliable and efficient energy storage for various residential, commercial, and industrial needs.
www.fogstar.co.uk www.fogstar.co.uk

Anyone heard of/had any experience with this mob? Seems a reasonable price for that amount of capacity and convenience.
Click to expand...
Yes, I bought 2 of their DIY kits a few months ago so have just under 32kWh. Reputable dealer, good quality cells from them and been around quite a while I believe. The DIY kits all went together well and have been working great the last few months.
 
Ron-ski said:
I guess I achieved the impossible, along with many others that have these batteries.

There is no regulation for 48v DC that I'm aware of. That said you really need to understand what you are doing, especially if setting up the BMS.
Click to expand...

What I meant is it's imposible in UK to create a commercial product around such batteries and sell it at scale.
 
Perfectly possible, Fogstar sell plenty of batterries, there's another company that's imports Chinese batteries, more than doubles the price and sells for a huge profit.

lemonenergy.co.uk

Lemon Energy

UK Based Battery Company
lemonenergy.co.uk

It all comes from China though, as does a large proportion of stuff, but Fogstar and Lemon Energy commercialised these products, and sell them in the UK, and I'm sure if I dig around I could find some UK built ones as well.
 
randal said:
www.fogstar.co.uk/collections/solar-battery-storage/products/fogstar-energy-32kwh-battery

Anyone heard of/had any experience with this mob? Seems a reasonable price for that amount of capacity and convenience.
Click to expand...

Myself and @Malt_Vinegar have the DIY Seplos V4 16kWh kits, below is Malts thread about it. As Ronski mentioned the 32kWh is f'ing heavy, just for practical reasons i don't think I'd go above the 16kWh in a single enclosure as it was just about borderline for me to man handle around. Plus depending on your setup, two does give more amps than a single if you need it.
https://forums.overclockers.co.uk/threads/diy-battery-solar-installation.18990008/


Depending on how cheap you want to go you can order x16 cells from them and x1 case for an all in price of £1319.83 for 16kWh

www.fogstar.co.uk

Envision LiFePO4 315Ah Prismatic Cell (Grade B)

315Ah LiFePO4 cells are engineered to deliver exceptional performance, making them ideal for crafting high-capacity 12V off-grid batteries for solar systems, campervans, and boats.
www.fogstar.co.uk www.fogstar.co.uk
www.fogstar.co.uk

SEPLOS V4 48V DIY Kit

The Fogstar/SEPLOS 48V DIY Battery Kit offers unparalleled flexibility for both residential and commercial solar battery storage needs.
www.fogstar.co.uk www.fogstar.co.uk
 
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Thanks all for your inputs and experiences, sounds promising.

I'm in a bit of a bind at the moment tbh. Currently I have:

24x440w panels with S440/S650B optimisers
SolarEdge SE5000H Inverter

GivAC3.0 + 9.5kW Battery


The optimisers on the panels tie me to SolarEdge for the generation, but I'm OK with that. I'm comfortable with (and now trained on, lol) the SolarEdge kit so I think I'm going to move to an 8kW inverter as planned.

However the battery/storage side of the house is where I'm undecided. The way I see it I have the following options:

1) Keep the GivAC3.0 and double the battery capacity by adding another Gen2 9.5kW battery

Pros
  • Easiest
  • Plug and Play
  • No DNO change needed
Cons
  • Expensive
  • Limited to 3kWh output from the battery to house/grid
  • Density. Twice the space needed over the Fogstar option.
  • Proprietary, can only use GE batteries.
  • Need to use an installer if I want the full 12 year warranty, else just 1 year if I source + fit myself.
2) Ditch the whole GE setup, go Fogstar + Victron??

Pros
  • "Open Source"
  • Price
  • Expandability
  • Offset cost by hocking the GE kit
Cons
  • DNO change (again)
  • Hassle of hocking the GE kit

3) Ditch the whole GE setup, go SolarEdge 400V Battery

Pros
  • Easy
  • Offset cost by hocking the GE kit
  • I'm trained, and certified (lol)
  • Single solution provider for all solar/storage
  • Expandable
Cons
  • All eggs in one basket
  • DNO change
  • Offset cost by hocking the GE kit
  • Multiple batteries/racking is large footprint

1+3 are easy from a hardware standpoint, 3 with the DNO pain. 2 is more interesting/open but with the DNO pain and cheaper. Not sure what kit to go for between the Battery and AC that would work with my existing SolarEdge inverter.

Unless there's a way of making Vicrtron inverters work with SolarEdge optimisers? I presume not though...
 
Victron can't use any optimisers, and SE optimises are only compatible with there own kit as far as I'm aware.

I'd suggest keeping the SE inverter and adding a Victron inverter for the batteries, if you went for an inverter with a changeover switch built in such as the Quattro you could have whole house UPS, it also opens up the very cheap 48v battery options, and if needed you could add more PV to it

Running in island mode (no grid supply) the Victron kit can control generation on the SE system, the Victron inverter must be more powerful than all other inverters combined though as it needs to alter the frequency to control other invertors, for example if the batteries are full and there isn't enough load to satisfy generation, it must be throttled back.

AC-coupling and the Factor 1.0 rule [Victron Energy]

www.victronenergy.com www.victronenergy.com
 
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Ron-ski said:
Victron can't use any optimisers, and SE optimises are only compatible with there own kit as far as I'm aware.

I'd suggest keeping the SE inverter and adding a Victron inverter for the batteries, if you went for an inverter with a changeover switch built in such as the Quattro you could have whole house UPS, it also opens up the very cheap 48v battery options, and if needed you could add more PV to it

Running in island mode (no grid supply) the Victron kit can control generation on the SE system, the Victron inverter must be more powerful than all other inverters combined though as it needs to alter the frequency to control other invertors, for example if the batteries are full and there isn't enough load to satisfy generation, it must be throttled back.

AC-coupling and the Factor 1.0 rule [Victron Energy]

www.victronenergy.com www.victronenergy.com
Click to expand...

I figured as much with the SolarEdge stuff, I can't be bothered to get on the roof to pull out all the Optimisers. Victron Quattro it is! I've long wanted the whole house UPS/islanding mode. More so after the power cut we had last night. Thanks dude!
 
Just make sure you find out what the DNO will allow before spending loads of money, if you have 8kW SE + 8kW Quattro, that's 16 kW export power, and I'm not sure what you'd need to do to satisfy the DNO if they don't give the full 16 kW export.

Any questions then just ask, or look in my signature for my build thread
 
Ron-ski said:
Just make sure you find out what the DNO will allow before spending loads of money, if you have 8kW SE + 8kW Quattro, that's 16 kW export power, and I'm not sure what you'd need to do to satisfy the DNO if they don't give the full 16 kW export.

Any questions then just ask, or look in my signature for my build thread
Click to expand...

Yep, for sure. I'm planning for the later phase(s) of the upgrade path at this point. DNO, then hopefully inverter upgrade to take care of the clipping, then look at the storage options.
 
With Fogstar, I'd be very wary of the warranty.

Sure, they claim 10 years, but they're just importing generic Chinese kits and slapping a premium on them.

5 years down the line when it goes pear shaped, I'll be very surprised if they're still here.
 
leezer3 said:
With Fogstar, I'd be very wary of the warranty.

Sure, they claim 10 years, but they're just importing generic Chinese kits and slapping a premium on them.

5 years down the line when it goes pear shaped, I'll be very surprised if they're still here.
Click to expand...

Even if you had to replace it after 5 years its still going to cost waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay less than something like Giv/Fox/Solax etc. for 32kWh - battery price will have also have fallen. Also you'd easily find someone who can do a cheaper repair for you.
 
That's part of the appeal to me with DIY from Fogstar, if a cell goes bad I can just replace it for £45, if the BMS dies then I can just buy a new BMS. I'll take my chances for a cheaper initial price and bear the costs of any repairs
 
leezer3 said:
With Fogstar, I'd be very wary of the warranty.

Sure, they claim 10 years, but they're just importing generic Chinese kits and slapping a premium on them.

5 years down the line when it goes pear shaped, I'll be very surprised if they're still here.
Click to expand...

The company is nine years old, I expect they still be here in another nine.

I also don't think they put that much of a premium on, there are those that do, just look at Lemon Energy for instance.

I'm not even sure you could get a ready built battery cheaper from China, especially if you get slapped with 20% vat.
 
Nice, the only downside of an install this time of year is you'll get to see your generation fall day by day as the days get shorter, but you'll get an idea of what your system is capable of straight away, presuming the good weather keeps up.
 
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I'm after more battery and not sure of the best route.

I currently have:

1x Powerwall 3 (13.5kWh) with 30x445W panels in 3 strings of 10
1x Solax 6kW String inverter with 14x645W panels in 2 strings of 7 with Tigo optimisers

I will likely add more panels at some point (north roof at least), but I definitely feel I need more batteries for the periods where Octopus decide my rate isn't 7p.

I see 3 main options:

1. Add PW3 DC expansions, 1 would take me to 27kWh, 2 would take me to 40.5kWh. Cost about £5500 each. Can pay for them on 0% finance for 3y. Integrates well with existing battery, don't need to make any changes to my automations. Can then charge from grid at 8kW rather than 5kW.
2. Replace the Solax inverter (which gets some clipping anyway) with a larger hybrid inverter, and get 2x Fogstar 16kWh batteries. This would cost around £6k for 32kWh, and slightly more generation (less clipping), but does mean I have to manage two batteries that won't talk to each other, I would have to take efforts to make sure one didn't charge the other etc.
3. Go the insane route, copy that guy off youtube, replace the solax inverter as above, and mount a recovered Tesla Model 3 LFP battery pack to my garage wall. A lot more work but I think I could handle it, about the same cost as option 2 I think (£6k), but would get me 60kWh. Has all the management drawbacks of option 2.

What would others do?
 
rtho782 said:
I'm after more battery and not sure of the best route.

I currently have:

1x Powerwall 3 (13.5kWh) with 30x445W panels in 3 strings of 10
1x Solax 6kW String inverter with 14x645W panels in 2 strings of 7 with Tigo optimisers

I will likely add more panels at some point (north roof at least), but I definitely feel I need more batteries for the periods where Octopus decide my rate isn't 7p.

I see 3 main options:

1. Add PW3 DC expansions, 1 would take me to 27kWh, 2 would take me to 40.5kWh. Cost about £5500 each. Can pay for them on 0% finance for 3y. Integrates well with existing battery, don't need to make any changes to my automations. Can then charge from grid at 8kW rather than 5kW.
2. Replace the Solax inverter (which gets some clipping anyway) with a larger hybrid inverter, and get 2x Fogstar 16kWh batteries. This would cost around £6k for 32kWh, and slightly more generation (less clipping), but does mean I have to manage two batteries that won't talk to each other, I would have to take efforts to make sure one didn't charge the other etc.
3. Go the insane route, copy that guy off youtube, replace the solax inverter as above, and mount a recovered Tesla Model 3 LFP battery pack to my garage wall. A lot more work but I think I could handle it, about the same cost as option 2 I think (£6k), but would get me 60kWh. Has all the management drawbacks of option 2.

What would others do?
Click to expand...
number 2 and 3 would also need a new g99 application for bigger inverter and disposal documentation for removed inverter.
 
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