Installing additional battery

If i want to add another 5kWh battery to 2 I already have, do i need an official installer or it is just a case of isolate and make necessary connections and power up?

I assume there will be an element of commissioning required, so that the inverter knows there is another battery and the battery will also need to do its commissioning discharge/charge

Cdent is that something the home user can do via givenergy page or requires engineer level access to perform?

It requires engineer level access, bit GE might be happy for you to do the work if you then evidence it with photos of the installation.

That's what happened with my battery after it arrived 6 months after the rest of the system, because it wasn't worth getting the installers up just for that one job.

Contact or email them and ask if they would be happy.

Have you managed to buy a second battery? Most distributors insist that you are a registered electrician - and Givenergy insist that the installer is 'Givenergy trained' (a 3 hour Microsoft Teams chat). I'm not an electrician - just a dim hardware/software designer ...

Slartibartfast Design it, sure... wire up a battery, no way! You'll have to pay someone who knows what they're doing ;-)

If you think most 'electricians' know what they are doing your deluded. It's only three wires - two big ones and a little one. Three hours Team chat to become an expert ...

Certainly for the Gen1 batteries, it is not as easy as 3 wires plus a 1.5 hours chat on Teams.

The DC power cables carry up to 100 Amps, so need to be correctly stripped back, then have ferrules crimped on to the exposed multi-strand copper, before connection in to the 100 A MCB and battery terminals. This is to avoid long term oxidation of the copper, which will readily cause over heating of the connection.
Get the polarity wrong, and there will be a big bang, and no warranty on some pretty expensive battery units.

Then every battery needs to be earth bonded with 4 or 6mm2 cable plus ring crimps. Cable and crimps not provided with the battery as far as I am aware.

How many DIYers have the correct crimp tools for the 16 mm2 power cables, and 4 or 6 mm2 earth bonding cables in order to to the job properly?

Never mind configuring the DIP switches correctly for master/slave and battery ID number.

It really is not comparable to wiring a 13 A plug top, or swapping a light switch front plate.

Even when adding a 2nd Gen2 battery, the earth bonding is required on top of the more simple pre-made cable with connectors both ends.

Actually, it is, for anyone with the tools and skills to wire a consumer unit and configure simple control equipment.

I'm not convinced that those skills were possessed by the team that installed my system.

No, let me re-state that:- Those skills were not possessed by the team that installed my system.

The training provided by GE is reliant on the installer being a good electrician in the first place, and clearly some are not.

I do have concerns on how a 2nd gen 1 battery can be installed safely, which may be why they are transitioning to the gen 2 battery with a built-in 2-pole isolator in each battery pack.

If I was to follow my workplace electrical safety processes there would need to be a means of isolation of the 50 Vdc from each battery pack, and this would need to be locked off and proved dead before any wiring work was carried out. These battery packs store a large amount of energy, so have the potential to generate significant arcing when connections are made.

With a hybrid inverter plus 2 batteries, there should be at least 4 lockoffs in place, a discharge time to observe, and finally prove dead before any wiring can take place:-

1/ AC feed.
2/ DC feed from PV.
3/ DC from battery 1
4/ DC from battery 2.

I would be very interested if any one go this route.
Manny people would install battery it self with out any issue. Crimped wires you can buy with out any problems as well as manual how to connect battery is widely available. Included how to position dip switches on battery.
I did not ask yet as i have fairly new system (2mc) but after winter if prices are stable im planing to add another battery 5.2 or 9.5 depends of price/capacity ratio. Any way calling "engineer" to connect battery its bit odd and possible paying £200+ for something you can do yourself its waste off money.

My installers - what earth bonding ...