Idiot's guide to a self build battery

[AGT]

Afraid that’s the start, rubber matting and 2x18mm sheet ply on floor
Waiting on deliveries and SP G99 approval

[Stinsy]

A nice start to the day, battery stack had went from 17% soc to 99% soc within the charging window. I'll leave it on its daily schedule, looks like a nice simple way to get that extra bit into the tank. The stack hit 80% soc at 02.20hrs. It will be great in Winter for running the ashp.

If I chose to I could also use the EV battery to run the add on charger, to charge the stack, to export to grid (or top up for a Winter hungry ashp). Can't see that becoming a thing but it's one more interconnect in place within the home. I will try it least once.

If anyone is interested for their own system? It is a chunky unit with a good cooling fan and excellent fins. Good quality flexible cables too along with an Anderson connector. All in all, a great, well built bit of kit. It should pay itself off incl postage in a little under 1.6MWh. About 6 months time.

https://a.aliexpress.com/_EvQESLO

Nowty, thank you very much for the logic switch offer but it looks like we're good.



Edit-
By completing the loop between EV and house stack which is V2H-G we raise the non intervention stack charging rate to 5.4kW (3.9+1.5) and the potential storage to 115kWh of battery. The potential export on that is in theory 70kWh in the 18hr window without solar if i get up at 05.30 and connect the EV (unlikely). The true charge rate of that 115kWh combined battery stack is 3.9+1.5+7.2 = 12.6kW. All for a £90 charger.

I am unlikely to go chasing this for export money but can see the scenario being used when the ashp is chewing through the stack in Winter. I'll be glad of it then.

I know a few people who get free EV charging at work. It’d be compelling to have a V2L EV and forklift charger arrangement if that were the case…

[Joeboy]

A nice start to the day, battery stack had went from 17% soc to 99% soc within the charging window. I'll leave it on its daily schedule, looks like a nice simple way to get that extra bit into the tank. The stack hit 80% soc at 02.20hrs. It will be great in Winter for running the ashp.

If I chose to I could also use the EV battery to run the add on charger, to charge the stack, to export to grid (or top up for a Winter hungry ashp). Can't see that becoming a thing but it's one more interconnect in place within the home. I will try it least once.

If anyone is interested for their own system? It is a chunky unit with a good cooling fan and excellent fins. Good quality flexible cables too along with an Anderson connector. All in all, a great, well built bit of kit. It should pay itself off incl postage in a little under 1.6MWh. About 6 months time.

https://a.aliexpress.com/_EvQESLO

Nowty, thank you very much for the logic switch offer but it looks like we're good.



Edit-
By completing the loop between EV and house stack which is V2H-G we raise the non intervention stack charging rate to 5.4kW (3.9+1.5) and the potential storage to 115kWh of battery. The potential export on that is in theory 70kWh in the 18hr window without solar if i get up at 05.30 and connect the EV (unlikely). The true charge rate of that 115kWh combined battery stack is 3.9+1.5+7.2 = 12.6kW. All for a £90 charger.

I am unlikely to go chasing this for export money but can see the scenario being used when the ashp is chewing through the stack in Winter. I'll be glad of it then.

I know a few people who get free EV charging at work. It’d be compelling to have a V2L EV and forklift charger arrangement if that were the case…

I've always thought that V2HWG in any form is the way to go.

We are charging the EV tonight for the 1st time in 3 days. In the interim we have been supplying our cul de sacs small daytime req's hopefully from our car. Or at least a facsimile of that .

We exported 67.6kWh yesterday which is without having to check a new PB.

This will be an interesting year as it's our first full year with everything moved into position and up toward the system max. That's already a tenner in a day barrier breached, SO early in this year of new things.

We could in theory with a tailwind and good fortune crack 100kWh exported in a single day. I'l be keeping an eye out for that. Won't be a consistent thing but would like the 1 day badge.

What size of forklift battery, what size of forklift fleet?

[MrPablo]

I helped a friend increase their battery stack from 17.5kWh to about 47kWh this weekend.
2 x 15s DIY batteries added to the system, still a little work to do to integrate a battery controller that will handle both the pylontech and JK BMS batteries into one system.

[NoraBatty]

I helped a friend increase their battery stack from 17.5kWh to about 47kWh this weekend.
2 x 15s DIY batteries added to the system, still a little work to do to integrate a battery controller that will handle both the pylontech and JK BMS batteries into one system.

Lovely job.
Ive been contemplating a server rack for our batteries that have the mounting flange on the face as it would make better use of the space in the shed but dont quite get how they work, especially for 130kg batterys as ive never seen one in the flesh.

Do you have to buy individual shelf units to seperate each battery, or are there bracing strips that run front to back, or do they all just sit ontop of eachother, which seems like alot of weight and no airflow?

[MrPablo]

Thanks NoraBatty!

The lower DIY battery is sitting on the rack frame itself, I designed it to be 6U in height so it fits well.
The upper DIY battery is sitting on a pair of these supports:
https://www.amazon.co.uk/dp/B083N35SCZ

The Pylontech batteries also have a pair of the supports below them, with each battery also bearing down via the rack ears.
We're looking at putting in a mid frame support so that any shelving (or cheap second hand Pylontechs) could go back to back.

If your boxes are 130kg each, my back would explode just looking at them.

I do like the way that Joe and my friend have arrived at a very similar setup. Different DIY enclosure/ mounting, but there's a lot of benefits to combining existing Pylontech setups with big cells sourced inexpensively!

[NoraBatty]

Thanks NoraBatty!

The lower DIY battery is sitting on the rack frame itself, I designed it to be 6U in height so it fits well.
The upper DIY battery is sitting on a pair of these supports:
https://www.amazon.co.uk/dp/B083N35SCZ

The Pylontech batteries also have a pair of the supports below them, with each battery also bearing down via the rack ears.
We're looking at putting in a mid frame support so that any shelving (or cheap second hand Pylontechs) could go back to back.

If your boxes are 130kg each, my back would explode just looking at them.

I do like the way that Joe and my friend have arrived at a very similar setup. Different DIY enclosure/ mounting, but there's a lot of benefits to combining existing Pylontech setups with big cells sourced inexpensively!

Benefits of having mechanical knowledge and messing about with engines, i have an engine hoist to lift with and its come in very handy with these batteries.

Definately alot going for it for sure, and i am sure your friend will be more than happy.
Thanks for the info. Muxh appreciated.
If i get carried away and want an extra battery, i would definately need one of these to make it work.
I very nearly bit the bullet with the cheap fogstars the other week but the other half stopped me, saying we should live with the current setup for this winter then see if we need another or not.
He had a point, but shiny shiny value for money

I note they also have them cheap currently, not as cheap as 44% off, working out 44quid each iirc