Buzzing or coil whine

Hey, I have a first Gen 1 5KW Givenergy hybrid inverter connected to a Gen2 9kwh battery.
16 JA 455KW south facing panels and only 2 years old.
It has been off for about 8 months and once I have turned it back on its buzzing or whining quite loudly when it get up to 4-5KW.
This definitely didn't happen before.
I have been struggling to get in contact with Givenergy, the Customer line keeps stating its closed whenever i call any time of day. and non of my emails are getting replied too.

If you have any information or incite please let me know.
Thanks

Why have it turned off? Why not charge battery at night on Eco7 at half price and use during the day rather than import.
Has the battery gone flat and now it will require some sort of GivEnergy or installer restart.
Plenty of posts if you do search for GivEnergy support https://community.givenergy.cloud/d/5237-phone-support/23

GMiddleton They are ultimately silent (they have no moving parts inside - inductors are potted and so on...)
I have had several Gen1's and none of them have noticeable wine even at full 5kW. "Whining quite loudly" is not normal.

So I'd first go back to your installer and get them to log the fault / look at it.

Customer care line has shut - so you won't be getting through on that.
Emails are also not doing so well as late either - there seems to be a huge backlog....

Installer support line however seems to have been preserved - so going via your installer is likely to yield quicker results (although likely at the annoyance of the installer but that's for them to take up with Giv about consumer support)

hoggy Thank you, do you have any incite why they have shut down customer support?
it was the installer who told me to contact them as its under the Givenergy warranty and not there's.

SteveCook I had to turn it off due to building works the other side of the house.
we are on Octopus Intelligent flux as it works out the best our return on our investment.

GMiddleton
Thanks.
IoF makes sense
But off for 8 months may have "killed" the cells.
When it was turned off, was there any holding charge left in the cells

GMiddleton I'm afraid I have no insight into the inner workings of Giv Support. It's not fully gone, it's just not available by phone and there appears to be some serious backlog from what I can tell.
I'd push back against your installer personally.

SteveCook No there was no charge left in the Cells when turned back on.
I asked Givenegy before i did it and they said it would be fine.
the battery was kept above 15C as its in the office and the central heating was still on.
why do you believe that might damage the cells?
My issue isn't with the battery its with the inverter making the noise.
today it also started making the coil whine when it was raining which was weird.

hoggy Thanks I will try, I attempted to call them today but there was no one in the office at all.

GMiddleton
Hi.
Only what I have read on these forums (do a search about dead battery).
People have said batteries are shipped with about 40% holding charge, however if they do not get sold/installed for a long while they can fully drain, or are allowed to go flat for a long while they may need some sort of "jump start" by an installer.
Does power for BMS come from the inverter connection to the battery or from the battery? IE if battery is "dead" there is nothing to power BMS? Just a thought

SteveCook sorry what is BMS? I have searched for the definition with no success.

Battery Management System.
When my BMS cable between my battery and inverter fell out of the inverter socket, I got loads of errors/warnings on my portal page about the inverter