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Checked my battery bank voltage last week and realized my 'fully charged' system was only at 60%
I've been running four 6V golf cart batteries for my off grid cabin for about a year now. Last week I finally bought a proper hydrometer to test the specific gravity of each cell. Turns out my cheap voltmeter was giving me wrong readings and I thought they were full when they were barely half charged. I found this chart online from Trojan Battery that shows exact voltage vs charge level and it totally changed my routine. Now I check with the hydrometer every two weeks instead of trusting the digital meter. The kicker is I had been running my fridge and lights like everything was fine but I was probably damaging the batteries by undercharging them for months. Has anyone else caught their battery monitor lying to them? What do you use to double check your state of charge?
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the_rowan1mo ago
Oh man, @nguyen.blake is right about the hydrometer but actually you gotta be careful with those too. Cheap ones can give false readings if the electrolyte temp isn't right or if you don't let the balls settle. Learned that the hard way after buying a new bank.
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logan5611mo ago
Fair question though, is it really that serious if you're just topping up water? @nguyen.blake makes it sound like rocket science but I've never had temp cause me problems.
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