Fogstar Seplos Mason Kits

[Stinsy]

I'm looking into these kits right now. If people had a choice, would they go for

A - V4 kit with Eve MB31 Grade A 314Ah cells (16.08kWh) for £1799, https://www.fogstar.co.uk/collections/s ... e-a-bundle

or

B - V4 kit with Envision Grade B 280Ah cells (14.34kWh) for £1399 ? https://www.fogstar.co.uk/collections/s ... e-b-bundle

I'll be buying 2, so overall its an £800 saving for the cheaper option, but slightly concerned at the lower grade B batteries there, but is it £800 worth of concern!?!?

Depends how long-term you see these batteries working for you. Are you expecting to be using them for 20 years or 30?

Who knows what the energy market will be like in 20 years, same for battery prices and technologies. Will you be living in the same house then? Do you even plan on being alive in 20 years?

[pudding]

I'm only 45 so bloody hope so! In our forever home so no issue with having to move them in future and no planned changes in electricity usage (already have HP's and EV etc), apart from kids leaving home in 10+years so only going to go in one direction.

Hopefully any battery will still have decent capacity in 20years+, but with the movement of prices in just the last few years, I don't think it'll break the bank if we have to replace them in 10-15years even, they'll have earned their keep long before then! Hmm...

[Tinbum]

As well as the price difference there is a cycle difference of 2000 between them too..

You have to be careful looking at these as often they change the % SOH they measure to etc etc.

[Stinsy]

As well as the price difference there is a cycle difference of 2000 between them too..

You have to be careful looking at these as often they change the % SOH they measure to etc etc.

Agreed!

A "6000 cycle" battery might say that 90% of them will still have 80% of their capacity at 6000 cycles. Whereas another "8000 cycle" battery might say that 80% of them will still have 60% of their capacity after 8000 cycles.

So which is better? The "6000 cycle" battery to the "8000 cycle" one? Well they're probably the same!

[John_S]

Another point to consider is that in a few years time V2G will come for CCS cars. The EV will be able to handle a lot of the requirements of existing home batteries.

There will obviously be cases where they won't, eg driver out in the EV all day and others at home, but in a lot of cases it will.

[Kommando]

I have an Envision grade B DIY 280AH battery using cells from Fogstar now just coming up on 10 months old and no issues, second 314AH 8 months old one is as good but younger. Use a JK pb BMS with 2a active balancer and they balance quickly, set to start at 3.44v with target delta 0.005v which takes 30 mins.

[Kommando]

As well as the price difference there is a cycle difference of 2000 between them too..

You have to be careful looking at these as often they change the % SOH they measure to etc etc.

Correct, it used to be 80% SOH, it's now 70% SOH, real life using the same SOH has only marginally improved.

[pudding]

Thanks, good to hear someone who has those exact same grade B cells, and to have some reassurance they're still decent, was it also a DIY kit from Fogstar?

Anyone else have Grade B cells? For the cost difference it seems like a good deal that I'm leaning towards, despite the slightly lower performance after x-000 cycles.

[Kommando]

I use the XR-07 DIY box including 200a jk pb BMS with 2a active balancer. It's on AliExpress and costs £380 ISH, comes via train and final delivery is by DPD with no surcharges/extras to pay.

[Stinsy]

I use the XR-07 DIY box including 200a jk pb BMS with 2a active balancer. It's on AliExpress and costs £380 ISH, comes via train and final delivery is by DPD with no surcharges/extras to pay.

Train?