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richard-1 asked

Solar vs generator feed to my AGM off-grid

I have had my off-grid system now for 6 years (Victron Multi + AGM batteries). In that time I have observed that solar input charges the batteries far better than a generator (pure sine wave). Being 6 years old but well treated, I suspect my batteries are near end of useful life because after one or two days of non-existent sun, they fail to hold voltage throughout the night. This is despite the fact that I run my gene at the end of every (poor sunlight) day to get to 100% SOC. When I have good sun, the batteries always behave well. Is this a known behaviour of generators and is there a way to get more 'power' to the batteries even though SOC is 100%?

Generator
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3 Answers
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Marc Heymans answered ·

The other issue is that during good sun conditions, the MPPT is putting a good DC voltage on to the DC bus, for the inverter to use which takes pressure off the batteries, and in fact they may not even be being used, so this gives the impression that the solar is charging the batteries better.

Running the generator in the evening may not be fully charging your AGM batteries (even though BMV says 100%) which also doesn't help your situation.

I hope this makes sense.

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conkev23 answered ·

Are the batteries charged at the same rate from either the solar panels or the generator?

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richard-1 answered ·

I will check and update post.

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