9.5kwh battery plus 5.2 any issues?

Anyone using this combo of batteries? Any issues? I know the 5.2 only has 80% dod but that along with the 9.5 should cover my worst days use in winter with no solar. The 5.2 connects to the 9.5?

michaelmcgoldrick afaik there shouldn't be any issues, but the 9.5 should be set as the master and the 5.2 should be the slave.

I have this combination of batteries connected to a GIV-AC3.0, the 9.5 is master and 5.2 slave.
It works well with no issues to report.

I have an AC3 with 9.5 and older 8.2 batteries. Works fine. Been in since end of October 2022

I have this combo as well. 5 KW Hybrid with a 9.5 master and 5.2 slave. No issues at all. The installer used the new cable to connect the two and just cut off the connector at one end to crimp for the feed into the 5.2 battery

If you add a second battery, does it charge both at the same time, or one then the other?

Once my house is finished, if there's enough left over to add another battery, we were thinking of doing so. Currently have a 5.2kwh

Anomnomnomaly The system sees it as one battery and they both charge at the same time

Anomnomnomaly If you've got room on the roof get a few extra extra panels as well, to make it all 0% VAT

SilverArt

I think if we add more panels, we'd need another inverter... we've got a 3.6kw one I think... We had to build the system to a budget rather than optimise for expanding later. There's room for 4 more 400w panels on the roof... but I was actually thinking of adding a couple of solar hot water panels and fitting a hot water tank to reduce reliance on using the gas boiler.

But after looking at the costs... I think using gas for hot taps and fitting electric showers in the bathrooms as we redo them would be better use of funds... Especially if we wait to shower until lunchtimes.... one of the advantages of working from home. 😆

can you get 3600w throughput from both the 9.5 and 5.2 batteries via the gen 2 invertor?

Anomnomnomaly It still might be worth looking at 1 panel to gain the exemption, depends how much clipping the existing inverter had to do in the summer peak and what your shortfall is the rest of the time.. It also may be worth asking your DNO if you could go for a higher output, to allow for a 2nd inverter.

SilverArt When you factor in the cost of them putting up more scaffolding just to add 1 panel to save 20% VAT... you're probably adding more than that 20% in extra costs.

My neighbour just had an extra battery fitted a few months ago, it cost him around £1500, VAT on that is £300... I'm betting the cost of 1 or 2 extra panels plus fitting would be a lot higher.

Anomnomnomaly we've got a 3.6kw

Do you know if it's a gen1 or gen2? According to the gen1 datasheet, the HY3.6 can handle 4.7kWp Max. DC Power and more panels would lengthen the harvesting season (ie earlier in the spring and later in the autumn). You just need to ensure that the maximum voltage won't be exceeded by the number of panels in your strings.

The gen2 HY3.6 has the same internals as the gen2 HY5 and a firmware update will re-rate it to 5kW. This might affect your G98 (soon to be G100) type testing and DNO application, but that's just paperwork, rather than money.

Is this a new-build that you can claim VAT back on anyway?

Tim

I've no idea if it's gen 1 or 2 I think it showed up on the router as HA-21 or something like that... the dongle failed yesterday, so we're waiting for the new one to be setup tomorrow and we also need to boost the wifi to it.

I know we've got the newest 5.2kwh battery... system was only installed a month ago.

Looks like this

The photo shows a Gen1 Hybrid inverter.
The plug in USB-WiFi dongle with the blue LED (just right of centre on the underside) is the give away.

Anomnomnomaly Nice picture but there's a Manufacturer's plate stuck onto the right hand side (of both inverter and battery) which gives the specifications and serial number. I defer to @Simon_C's ability to be able to differentiate a gen1 from gen2 but the plate will be the best evidence you can get. It won't state gen1/gen2 but it will give other clues such as maximum DC charge/discharge.

Hi folks, for anyone with a 9.5kwh battery and 5.2 what does your app show? Does it show one battery with 13.6kwh capacity or both? I had my 5.2 added today to my 9.5 and calibration just finished. In the app I can only see the 5.2 under battery percentage.. installer assured me would all look fine just give it a day ?

I just needed to sleep... Both batteries now showing in the app with the 9.5 as primary and 5.2 as secondary