I have a Skylla IP44 12/60(3) running two banks of AGM Super Cycle batteries. The battery banks are not holding a charge (voltage drops prematurely under load) and I've been advised by my Victron distributor to try equalizing the banks. The equalization voltage is set to 15.9V, but when I put the charger in manual equalization mode it won't put out any more than 14.6V. Charger state is showing as "Equalize" on my CCGX.
What am I doing wrong?
Hello.
What is the load level under this situation (is there any load)? If your load is more than (or close to) the output of your charger then the voltage will be held back. Are you able to try the equalisation with the banks isolated from any loads?
Cheers
The load was nowhere near the charger output. One bank had 5-6 Amp load, the other had no load at all. It's a 60Amp charger.
What current is the charger putting in? If it's maxed out then perhaps you have a dropped cell in the bank. This could explain both the low voltage when trying equalise and also the fast voltage drop under load.
First, thank you for your help - your input/thoughts are much appreciated.
I was monitoring the Skylla charger output voltage on the VRM portal, and that's were I saw a maximum of 14.6V when I put the charger into equalize mode. I don't think the batter monitor voltage got much above 14.1 or 14.2.
Would a dead cell prevent the charger output voltage from reading 15.9V?
Also, this happened on two separate banks, each with three AGM Super Cycle batteries. I suppose both banks could have the same number of dead cells ...
Of course all I suggest below could be way off the mark!
Yes it is possible, the input voltage will be pulled down by the bank, until the battery charges to that voltage. Where you have a failed cell the battery internal resistance goes down and will make it just that much harder to bring the voltage up (think 5 cell battery now instead of 6 cell). I guess it's less likely that both banks have failed, but from what you describe with both the charging and load issues, it does sound like there is a failed battery/cell issue. If possible separate out each battery and charge them one at a time - see how this goes.
