Who's got the biggest (battery)?

michaels

Just thought for a laugh (and possibly useful info) we could have a survey on battery sizes and what other kit they are paired with.

As it is my thread I will go first.  I have a V2G unit and 3 cars that can link to it with battery sizes of 24kwh, 40kwh and 62kwh although useable is probably about 12kwh, 30kwh and 48kwh due to discharge limitations so lets say 90kwh

Max discharge rate is about 5kw and with all available chargers including granny, max charge rate is 13.5kw.  I have a 7 hour cheap rate window @ 7.5p per kwh.

We also have 4kw nominal of PV and sort of a heat pump and sort of no gas heating.

pete-20-11

I have an infinity battery. 🤣

It's called the grid - on intelligent flux so I can borrow from the grid for the same price as I donate to the grid later (solar export).

ed110220

I've got a 15.2 kWh Seplos Mason 280L battery, it's a kit from Frogstar that you assemble yourself. It's hooked up to 4.8 kW of PV via a Growatt SPH5000 inverter. Unfortunately although the Growatt can output up to 5 kW AC (hence the name) from either the PV or a combination of PV + batteries, it can only charge and discharge batteries up to 3 kW so I'm only able to top up about 9 kWh each night on the Octopus flux rate.

michaels

ed110220 said:

I've got a 15.2 kWh Seplos Mason 280L battery, it's a kit from Frogstar that you assemble yourself. It's hooked up to 4.8 kW of PV via a Growatt SPH5000 inverter. Unfortunately although the Growatt can output up to 5 kW AC (hence the name) from either the PV or a combination of PV + batteries, it can only charge and discharge batteries up to 3 kW so I'm only able to top up about 9 kWh each night on the Octopus flux rate.

Interesting.  Do you find the 3kw restrictive for discharge as well?  Do you know what is causing the limitation and whether you could change the system to work around it?

Do you have islanding?  We don't, we actually have incredibly few power cuts but that doesn't mean the geek in me wouldn't lie to have it.

ed110220

michaels said:

ed110220 said:

I've got a 15.2 kWh Seplos Mason 280L battery, it's a kit from Frogstar that you assemble yourself. It's hooked up to 4.8 kW of PV via a Growatt SPH5000 inverter. Unfortunately although the Growatt can output up to 5 kW AC (hence the name) from either the PV or a combination of PV + batteries, it can only charge and discharge batteries up to 3 kW so I'm only able to top up about 9 kWh each night on the Octopus flux rate.

Interesting.  Do you find the 3kw restrictive for discharge as well?  Do you know what is causing the limitation and whether you could change the system to work around it?

Do you have islanding?  We don't, we actually have incredibly few power cuts but that doesn't mean the geek in me wouldn't lie to have it.

It's a bit restrictive, but not as bad as it might seem. I try to keep our consumption under 3 kW when relying on the battery by not running more than one high power device at a time. Sometimes that's not possible eg if using the oven and the hob on high. But even though the instantaneous import might be high it doesn't actually add up to many units because it isn't for long.

I don't know why Growatt made all their SPH series like this, I'm guessing economy? All of them from 3 kW to 6 kW AC output have the same 3 kW battery charge/discharge limit. It's in the datasheet so I think it's hardware not a software limit so there's probably no way around it: https://midsummerwholesale.co.uk/pdfs/growatt-sph3000-6000-hybrid-datasheet.pdf 

The datasheet suggests it supports islanding, but I've never looked into it as power cuts are so rare here it hasn't really occurred to me. I live in a suburban area with underground power supplies, but used to work in a village just a few miles away where the power was overhead and the power would go off and a backup generator would come on at least once or twice per year when there were high winds, so if I lived somewhere like that I'd probably find it useful.