Seplos mason battery build [Should I get 2 x 5kWh or a 10kWh battery?]

Was trying with getting a diesel gen late in the summer as we have the odd powercut here. But it's infrequent maybe 3 times a year at max so reconsidered and left it.

The recent power cut has me now back to this but instead buying some batteries that would get more storage use.

No solar yet but it's coming next few years.

Ahead of that thinking of using night rate as presently charge far via zappi for that.

High level presume need battery case, bus, batteries. So a seplos mason kit handiest with the fogstar pricing which seems reasonable.

And then an invertor, is the Solis 5kwh hybrid a good option. Considering solar installation within next12 to 18 months.

Or something else ?

Thinking more series 5 like

https://www.solisinverters.com/ie/energy_storage_inverter5/S5-EH1P%283-6%29K-L_ie.html.

Cant do PV yet as need entire roof membrane replaced the old under tile bitumen is falling apart. So there's roof work required tiles to come off, have to get that out of the way in spring.

Is the sunsynks better due to its higher current handling and 5.5 over 5. Or any particular reason.

Might note, not looking to use a generator at all so charge input may not be a requirement. Plan would be to trim down use to minimal during power outage. Few led light circuits. Heating a few times on. To extend battery power.

Presently without power at all but have been using the V2L to run the heating then top up the freezer.

Hi, ok started build have a couple of questions:

Fogstar have included 3 different types of buzbars just wondering which would be the best to use, the ones with labels appear to be aluminium flexi the thinner unlabelled seem to copper plated with aluminium again flexi and then there are some aluminium non flexi as in the second photo joining the two rows.

Also as the battery terminals are double tapped should I use both connections for the balancer wires and NTC wires or stick them all on the one connection?

Thanks

Ok, so all complete, worked first time…ish (balancer power was wrong), cells seem spot on, will see what happens when they start charging/discharging.

Trying to get hold of the sparks to do the swap from WECO to Seplos, might get some cables made up and swap myself leaving the WECO's in place in case there are issues with the Seplos.

So cables would need to be what 25mm sq 8mm lug to bare or do you put a ferrule on the bare end?

It'll be connecting to the 125A breaker.

Thanks, there's a crowd near Newry that make them up to what ever specs you want length, cable size 25mm, 35mm etc lugs m8, m10 or bare.

The breaker is already in situ as original install was 2 x 5.3KwH WECO's so will remove existing cables in the breaker from battery and connect in the Seplos, this way any issues I can easily switch back, once satisfied will remove the WECO's (flog them) then tidy up install.

Pink foam is to keep any dirt out until I put the panel on, want to leave it off for now so I check the connections/busbars etc for any heat spots once its charging/discharging.

Perfect, thanks for the reply graememk, a lot to consider.

I was looking to connect it up initially to the WECO's with the WECO's switched off to get a couple of cycles on it hopefully to get a good capacity measurement on it.

Regarding the SOC measurement if I run the WECO on the Solis and use the Solis to WECO CAN setting the WECO BMS will report the actual SOC of the WECO's only?

If I set the Solis to user define and set the battery capacity as Seplos capacity + WECO capacity (514Ah)…….would this work and give me a usable-ish SOC?

Thanks, 315 from a 280 cell thats good, did you capacity check them all?