Battery Flat

Help, I need to charge a flat battery and my installer is wanting to charge me, but threatening me with loss of warranty if I try to go to someone else. I've have had a nightmare installation journey starting 18 months ago when they installed 15 panels and a dangerous system (exposed wires etc). Following a show down with the contractor they came and fitted a new GivEnergy inverter and battery, which I was very pleased with, until Octopus Energy came and fitted a SmartMeter and it went wrong again. Finally, after waiting nearly 4 months the installer returned to rectify a fault that GivEnergy identified in their installation photos. But following this, they have informed me that the battery is flat and cannot be bought back into use without recharging (panels won't do it). The issue (apparently) goes back to the Smart Meter installation where they didn't reconnect something they should have. So now I have a flat battery and no way of getting it back without paying out more. Has anyone had to charge their own battery? Or got someone in to do it? Is it very difficult?

PL
Contact give energy ( I did ) & and they can give you advice, I have a flat battery also & LOTS of installation issues, some like yours, a LOT of cowboys out there, plus the work get handed to 3rd party's also....
My electrician is going to bring my battery back to life, when he sorts all the other mess out.
I went online to check they were MCS certified, that helps.
just found the info from give energy its a "60V 5A DC charger, well that's the info they gave me, I have a 9.5kw gen 2 battery.
Am fairly sure you cannot do this yourself though ?.
Best of luck.

Certainly not a recommendation that you DIY, but this might be relevant:
https://kb.givenergy.cloud/article.php?id=77&oid=1

PL To be fair its not your installers fault that Octopus screwed up.

It could take several hours to manually revive the battery so I think its only fair you pay for their time.

Go after Octopus for compensation.