question

missy avatar image

80% battery at 10.99V

I have three 100ah AGM batteries in my campervan. I've used them for 2 years.

(also a 390w solar panel, victron mppt and battery monitor)

Recently, staying in Portugal with high temps, although I've reached 100% battery each day, by morning I'm at 75 or 80%. My fridge tries to start up, runs for a few seconds then stops. When this happens, it takes my batteries from 12.17V to 10.99.

When there's enough light on my solar panel the fridge runs fine.


Being agm batteries, I can use 50% of their capacity. Its frustrating to be at 80% but still not have a working fridge!

Would new batteries help? I don't recall having this problem before, so I'm guessing they just aren't holding their charge as well as before.

screenshot-20210914-075524-comvictronenergyvictron.jpg


battery capacitybattery system voltage
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A screenshot of the mppt history would be useful to determine the batteries charge state/health.

1 Answer
devodave avatar image
devodave answered ·

Those symptoms indicate your batteries have aged to the point they no longer hold a charge.

If you take them to an auto-electrician he will usually have a battery analyser tool which will confirm that.

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Thanks, that's what I suspected... I'll look into upgrading to LI04 I think.