Hi Folks;
Quick question, I have the absorption voltage set to 15.2v and it never gets past 14.6v
Does anyone know why this could occur?
Application is Multiplus 2x120 and (4) Trojan T105 SLA’s
Why so high? Trojan spec sheet gives absorption voltage as 14.82V!!
15.2 is an equalisation range voltage, and should only be applied once a month or so, once batteries are fully charged and with no other loads on the system. Not surprising the volts won’t go above 14.6V.
I’m trying to trick it into doing a proper equalization at 16.2v
According to the docs, equalization adds 1V to the absorption setting.
Thing is, it will never go over 15.90v during equalization.
Unfortunately, Victron does not seem to let you set the equalization voltage - which is very strange.
That’s what I thought too. Even though these are deep cycle I tried the traction setting and upped the absorption to 15.2 so that it should hit the desired 16.2v when equalizing. Still won’t go above 15.90v no matter what. DC loads or not. I suspect it’s a problem with the firmware design?
Did you check the current from the charger (DC Clamp meter or connect reading?)
As the charge current is limited during equalise, the voltage could be very slow to rise.
Also if the 6v stage voltages are very similar, further equalisation may not be needed.
It’s being reported by the VIctron Shunt to the CerboGX.
The more I think about it, the more I think the firmware for the Multiplus series needs a revamp. You can’t set the actual absorption voltage. I don’t think they have ever supported absorption.
If you have temperature compensation enabled, that will affect the target voltages, reducing or lowering as required.
Good point, but I took that into account too. I tried this in the winter when it was sub-zero - same thing. Pretty sure they forgot to complete the firmware for the Multiplus 
Either that or they just assume that everyone is using lithium.
Unlikely, very little change and it is widely used still in the lead world. Plenty of people using it. The default is very much for legacy batteries. Must be something else going on.
I really don’t understand how anyone can equalize batteries when you cannot even tell the firmware what voltage they must be equalized at…this value is given in the spec sheet for the particular battery. Yet, it cannot be entered anywhere in the firmware.