Hi Everyone,
With MK Deka Gel batteries the manufacturer states a max charge voltage of 14.58V on a 12V block.
With a Victron MPPT, if we enable temp compensation - then the controller could exceed this in very cold conditions.
If we don't enable temp compensation then the batteries won't get as well charged in cold conditions.
I can't understand why there isn't a max charge voltage on the temp comp settings ?
Thanks,
Mark.
Because max charge voltage changes with temperature. Your maker is giving a max at standard temp. Set absorption voltage (max charge voltage) as per instructions and enable compensation.
Hi, thanks for your reply. No, this is the absolute max voltage at 15 deg C... as per their tech note (and confirmed with their tech staff in the USA) :
@Solar Tech you have to use the temp compensation figures that Deka provides.
It looks like it is -18mv/C for a 12v battery @ 25c. Do check those figures.
Yes, I have.... those figures are for 15 Deg C with a co-efficient of 0.003 Mv / cell / deg C .... as per their document below (and confirmed with their tech staff in the USA), which equates to 14.58V (2.43 vpc).
I quote Deka : "Continuing to temp. comp below 15°C the change voltage will be above our max. charge voltage recommendation."
"and so a voltage limit should really be set ? Correct. Max. Charge voltage should be set to 14.58V (2.43 vpc)"
See highlighted text:
Yes... from 25 deg C down to 15 deg C. At that point it should stop.
And in a hot climate the minimum charge voltage is at 35 Deg C. (both highlighted).
