Temperature Compensation--Battery or Ambient?
OK I have had my fill of why you need a temp comp probe to the battery casing or battery post (whichever one this week it is supposed to go on, the neg or the pos :) ) I understand temp comp and ag...
Forum Discussion
Hi BFL13,
Until recently I did not have the Magnum. My PD 40 amp maxed out at 14.4. I would see 15.4 volts on my Blue Sky during the cold months. The Blue Sky max is set to 15.4. I did not document ambient temperature vs voltage.
My modus operandi was to bring the RV to the house for two days and plug in to warm it up. On the second day I'd put in the food and add water for the upcoming trip. The PD would rarely go to 14.4 but would often start at 13.6
I can say that two winters ago when my panels got buried in snow that after 2 days starting at 14.4 from the PD, that, after I cleared the snow the Blue Sky immediately went to 15.4 volts.
I have seen the PD jump up from 13.2 to 13.6 when there were no loads other than parasitic (mainly the DC circuit on the fridge while being operated on 120 volts). The RV had been sitting empty for five days, and my solar panels were 100% shaded.
I also observed 15.4 when boondocking in small towns with 3 shore power cords maintaining heat and charging the battery bank after driving 350 kilometers at -27 C.
I consider the above statements to be anecdotal rather than real data.
I don't know of any "real studies" that have been done, unfortunately.
I have come across a gassing voltage and charging voltage vs temperature spread sheet. I no longer remember where I download it from.
This winter I will likely do one of my "back yard" tests with the Magnum as the primary charging source. Then, I'll perhaps have some answers to your thread.
Until recently I did not have the Magnum. My PD 40 amp maxed out at 14.4. I would see 15.4 volts on my Blue Sky during the cold months. The Blue Sky max is set to 15.4. I did not document ambient temperature vs voltage.
My modus operandi was to bring the RV to the house for two days and plug in to warm it up. On the second day I'd put in the food and add water for the upcoming trip. The PD would rarely go to 14.4 but would often start at 13.6
I can say that two winters ago when my panels got buried in snow that after 2 days starting at 14.4 from the PD, that, after I cleared the snow the Blue Sky immediately went to 15.4 volts.
I have seen the PD jump up from 13.2 to 13.6 when there were no loads other than parasitic (mainly the DC circuit on the fridge while being operated on 120 volts). The RV had been sitting empty for five days, and my solar panels were 100% shaded.
I also observed 15.4 when boondocking in small towns with 3 shore power cords maintaining heat and charging the battery bank after driving 350 kilometers at -27 C.
I consider the above statements to be anecdotal rather than real data.
I don't know of any "real studies" that have been done, unfortunately.
I have come across a gassing voltage and charging voltage vs temperature spread sheet. I no longer remember where I download it from.
This winter I will likely do one of my "back yard" tests with the Magnum as the primary charging source. Then, I'll perhaps have some answers to your thread.
