Solar Panel/ Battery issue

[Biggles]

We have an array of 16 solar panels and have noticed that the yield has dropped a fair bit in the past 8 months or so. There is an error showing on the inverter referring to the battery pack.

Now, assuming the fault is in the battery pack, would that cause the system to register less energy production than if the battery was working OK?

The battery pack has two banks, and one bank seems to be working properly.

The voltage from the two banks of solar panels is within +-8v of each other, sometimes one has more, sometimes less. The current however is showing about half on one bank compared to the other. These measurements are taken from the inverter data.

I'm guessing that one bank of panels feeds one bank of the battery pack, and the other solar panel bank feeds the other battery bank.

Could the battery fault cause the inverter to accept less power from one bank of solar panels?

I would have thought that if the inverter was smart enough, it would just divert the power to the grid, or house load.

We are going to get the original installers back to sort it out, but in the mean time I'm interested in finding out how these things work (or don't in this case!).

[Fredxx]

What is the battery voltage? You'll have to give more details of the installation. Is the intention here to live off-grid?

Yes, if the inverter thinks it has nothing to charge.

Again, you'll have to give more details of the installation.

Is this an MPPT inverter? If one bank is charging with a lower current I would expect the panel to be showing a different voltage

Normally battery packs are combined. Again, you'll have to give more details of the installation.

More info required.

[Nick Cat]

what is the error?

I wouldn't assume that, though it's more likely

depends where it's being metered

that's a huge difference. What's the bank voltage?

another big difference

such guesses aren't really useful

maybe. But maybe is no use to anyone.

depends what it's designed to do. You havem't told us.

Start with the manual. Show us. Then we can answer your questions. Until then we don't know what sort of setup you have, how it works normally, and all you have is guesses, which arent really useful.

NT

[Andy Burns]

I thought the strings could be up to ~600V, wouldn't take much shadow or bird shit to make a 1% difference

[charles]

when the BBC installed a solar powered tv transmitter in the west of Scotland, some energy had to be deployed on a wash/wipe system because of seagull crap on the panels. Not to be outdone the IBA installed a solar and wind powered transmitter in Cornwall. A storm snapped a blade of the wind generator and it dropped onto the solar panel and smashed it. Luckily for the viewers, this site also had mains power.

[Nick Cat]

Ah, I see I misread it as 8v difference in battery bank voltage. PV panel V_out varies greatly.

NT