Leaving RV MH Plugged in at Home
Had an asphalt pad done last year next to garage for the MH. Today I'm running dedicated 30 amp breaker and wireing/outlet to outside wall next to the pad. Question for those of you who have an outle...
Forum Discussion
Hi,
Sorry BFL13, but my research suggest your figures for gassing don't quite work.
From a spreadsheet that I found online. Temperature range is -30c (-22 f) to 50 c (122 f). It is unlikely that 13.8 volts is going to cause gassing, except in places such as Mesa, AZ, in the worst of the summer heat (gassing at 50 C (122 f)). 14.4 will at 21 C (70 f) and up. At -25 c (-13 f) 14.4 is not enough to even fully charge the battery bank. I've observed that happen this winter. So thank goodness I have solar. It is also good that I can charge either bank from solar.
It also means at 20 c (68 f) and below, that the PD "shot" of 14.4 every 20 hours for 15 minutes does absolutely nothing to destratify the batteries.
Another conclusion is that below -30 c (-22 f) there is no way to adequately charge the battery bank unless the disconnect switch is used to prevent damage to the various computer boards in the Fridge and etc.
I know these numbers "fly in the face" of folks with single stage 13.8 volt converters--but that is because the battery itself is above the ambient temperatures. Conclusion? For good charging, battery temperature needs to be monitored.
These numbers are why I wanted (and shortly will have) temperature compensated shore power charging.
temperature in C, charge voltage, gassing voltage
-30 16.2 19.2
-25 15.12 18.78
-20 14.04 17.82
-15 13.99 16.86
-10 13.92 15.9
-5 13.86 15.57
0 13.8 15.24
5 13.74 15.03
10 13.68 14.82
15 13.62 14.655
20 13.56 14.49
25 13.5 14.34
30 13.44 14.19
35 13.38 14.055
40 13.32 13.98
45 13.26 13.89
50 13.2 13.8
Sorry BFL13, but my research suggest your figures for gassing don't quite work.
From a spreadsheet that I found online. Temperature range is -30c (-22 f) to 50 c (122 f). It is unlikely that 13.8 volts is going to cause gassing, except in places such as Mesa, AZ, in the worst of the summer heat (gassing at 50 C (122 f)). 14.4 will at 21 C (70 f) and up. At -25 c (-13 f) 14.4 is not enough to even fully charge the battery bank. I've observed that happen this winter. So thank goodness I have solar. It is also good that I can charge either bank from solar.
It also means at 20 c (68 f) and below, that the PD "shot" of 14.4 every 20 hours for 15 minutes does absolutely nothing to destratify the batteries.
Another conclusion is that below -30 c (-22 f) there is no way to adequately charge the battery bank unless the disconnect switch is used to prevent damage to the various computer boards in the Fridge and etc.
I know these numbers "fly in the face" of folks with single stage 13.8 volt converters--but that is because the battery itself is above the ambient temperatures. Conclusion? For good charging, battery temperature needs to be monitored.
These numbers are why I wanted (and shortly will have) temperature compensated shore power charging.
temperature in C, charge voltage, gassing voltage
-30 16.2 19.2
-25 15.12 18.78
-20 14.04 17.82
-15 13.99 16.86
-10 13.92 15.9
-5 13.86 15.57
0 13.8 15.24
5 13.74 15.03
10 13.68 14.82
15 13.62 14.655
20 13.56 14.49
25 13.5 14.34
30 13.44 14.19
35 13.38 14.055
40 13.32 13.98
45 13.26 13.89
50 13.2 13.8
