question

laurapakora91 avatar image
laurapakora91 asked

SOC issues

Hi,

I have a van conversion with three expedition agm batteries with a combined C20 of 285ah. They are charged through solar and DC2DC.

I have been having ongoing issue with getting my SOC, used amp hours and voltage to align. I don't use the voltage to heavily to indicate charge as I know it's influenced by loads and temperature so I just make sure it doesn't fall too low. I can't seem to get my percentage SOC and my used amp hours to line up. I previously set my chargers to AGM spiral as the battery seller advised but reduced my absorption and float as told on another post. Otherwise I'm not sure what else to tweak, I've watch the victron video a lot and even used the peukert calculator. Kinda a normie trying to be a techy so any help would be really appreciated.

Many thanks, Laura


screenshot-20230306-172047.jpg





screenshot-20230306-172040.jpg


screenshot-20230306-182310.jpg

SmartShunt
screenshot-20230306-172040.jpg (285.5 KiB)
screenshot-20230306-182310.jpg (276.8 KiB)
screenshot-20230306-172047.jpg (293.4 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
Mike Dorsett avatar image
Mike Dorsett answered ·

Do make sure to align your charge settings exactly with the manufacturer's recommendations. More lead acid batteries have been ruined by under charging than through any other cause. Whilst excessive voltage during float or bulk charging can cause excessive gassing and plate corrosion, undercharging leads to sulphation.

If the temperature compensation, and temperature sensor are configured correctly, using the manufacturer's voltage settings should give the best results.

The SOC is an estimate based on calculations, consumed Ah would be more accurate for determining remaining charge. Getting these to 'align properly' is generally very difficult and a waste of time.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.