Battery Monitors

Harvey51 wrote:
I don’t find it complicated or in need of micromanagement. I charged it fully, set the amp hour capacity and 100% charge on the monitor when I first installed it. The solar charge controller keeps on charging slowly after the monitor reads 100% but the monitor doesn’t go beyond 100%. It has recalibrated itself so 100% means charging has replaced all the amp hours used since it was last fully charged. No adjusting ever. No doubt it is getting less accurate as the battery capacity diminishes but I always know when I’ve got a full charge. ( snipped para 2)

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Not sure the following applies to the above, but there is some cause for worry in the way it is worded. Not trying to teach Granny how to suck eggs!

First issue is the AH capacity set. At just above freezing at 35F say, capacity can be 15% less than at 77F.

Second issue is charging efficiency where some of the amps go to heat. If the AH counter just goes back to what it was when AH were taken out, you are not back to where you were by some percentage. Usually, they say you need about 115% to get back to where you were.

With solar charging stopping at dusk, a Trimetric monitor will auto reset its AH counter like it does when "charging stops" when it thinks the batts are full. ( I think the Trimetric method of identifying Full is bogus, but never mind that) So Trimetric says to turn off the automatic reset feature if you have solar.

So now with solar, the Trimetric will just keep counting AH in and out and you have to reset it yourself whenever you can get to true full (as measured independently).

If you do not reset your monitor fairly often, it will be hopelessly out of whack, which could lead you to have undercharged, sulphated batteries.

We have had guys come on here who found their batteries shot while their monitor said they were fine. They had no clue about how much to believe their monitor's reading of percent SOC).