Battery State of Charge meter function

[Kim G]

I have a small boat powered with a 48 Volt AGM system and DC motor. Similar to a golf cart set up. I have a Curtis 909R state of charge meter on my dash. Fully charged it reads 100% of course. I use this often but only discharge to around 80%. I would like to charge the batteries when approaching 50% on the meter. But each time i turn off the key until my next use (minimum several hours), I find when I turn the key back on the meter resets to 100%. How can the battery recharge by itself? I have not plugged it in to recharge yet it still resets to 100%. I’m not great with electrical knowledge but this is a puzzle to me. Thanks for any help!

 

[Scott Danforth]

welcome aboard.

start reading on recovery voltage or voltage rebound

 

[Kim G]

Roger that. Thanks for the direction!

 

[QBhoy]

Don’t suppose you have a charge status gauge that’s more suited to a 12v system ? Failing that…it will be as a result of the very thing suggested above. But thought I’d throw in the wild card thinking

 

[Kim G]

The voltage rebound that I have read seems most likely and would not present a problem at least. Brand new AGM’s, top notch charger and very good cables etc, so I don’t know what else to ascribe it too. Maybe a different way of monitoring the bank. Thanks for the help! Being a “recruit” I feel I should salute a Vice Admiral