I have (3) 200Ah SuperPacks (12.8V) in our Sprinter that charge up to 13.2V (100% SOC) using our alternator while driving by morning they are down to 12.8V. How do I test each battery to check if there is something wrong with a battery?
This is a fairly new issue. We turn the invertor off over night so only the refrig and diesel heater are drawing off the batteries.
Charging at 13.2V will not get you to 100%, did you mean 14.2V.
What is telling you that the SOC is 100%, is it a Smartshunt and if so what settings do you have on it (post a screen shot from Victron Connect).
Agree…alternator charge runs through Cyrix-Li-Ct so 13.2 up to 13.4v. Also have MPPT 100/30 attaches to (3) 100 watt solar panels that help when drivng or parked.
Yes have Victron Smart Shunt that sends info to the BMV712. See attached screen shots…
Appreciate the assistance.
I have a feeling that your SmartShunt is going to 100% before your batteries are actually full with the charged voltage set to 13.5V. Then you think you have full batteries but you do not. Normally I recommend setting it 0.2V below absorption, so 14.0V. Therefore, it goes to 100% when the voltage is above 14.0V and the current less than 5% of 600 = 30A. Your solar could easily trigger this in poor light.
Change the SmartShunt settings and give your batteries a good charge getting them up to 14.2V, then you know they will be full and the SOC is 100% and then work from there and see if you are getting low voltage. My feeling is you are undercharging and not seeing this.
See my FAQ
Ok…thank you the advice. I have made that change and we have a 5-hour drive tomorrow. I will be able to use shore power tomorrow night to fully charge the batteries. Ill update thread afterwards.
It is important to remember that the SOC can drift slightly each day and the inaccuracy builds up the longer you go between full charges. Making sure the shunt only resets to 100% when truly full is important. Lithium do not need to be fully charged routinely, but if they get a full charge every so often (2 weeks to a month) it resets the SOC and clears the slow drift. You may not see 100% as often as you have in the past, but that is OK.
