Battery charging question.
We are in our 3rd fifth wheel now and have boondocked some. New to us 2016 KZ Durango does not have an onboard generator. Plan to get a 2000-2500 watt portable generator. KZ has only one battery and a...
Forum Discussion
PanhandlePlainsman wrote:
I need more explanation on the application of the temperature chart.
Battery charging "charts" are set up for 25C (77f) and most charts list the charging voltage at 13.5. Gassing voltage is 14.34 volts.
The speed of chemical reactions approximately doubles for each 10 degree C (18 f) that the temperature increases.
As the temperature gets higher, the charging voltage should be lower to prevent extra erosion on the positive plates. At 50 C (122 f) charging voltage is just 13.2 and gassing voltage is 13.8
As the temperature gets lower, then charging voltage needs to be higher to "drive" the charging. At -30 c (-22 f) charging voltage ought to be about 16.2. This is a problem for an RV, because the computer boards for the fridge, furnace and other devices may only be rated about 15.4 volts. The battery will still charge at a lower voltage--but it may take a lot more time.
For example, at 12.8 volts, and 25 c (77 f) it may take 168 hours to fully charge a battery.
I hope this "thumbnail" of what may happen helps.
