Strange electrical query

[MacGumbo]

Just returned from a camping trip and was leaving the shore power disconnected several days to to exercise the battery.

Battery level dropped to 1/2 and I could tell the overhead lights were dimmer than normal. I hooked up shore power and noticed the lights had not increased their illumination. I checked and noticed the voltage was still low. Thinking I may have a power supply problem, I began to get my tools together and so I wouldn't be drenched in sweat, turned on the A/C. As soon as the A/C came on all the lights began to illuminate correctly and voltage jumped to 13.6.

After that it has been working fine and the battery is charging.

Any ideas?

[MacGumbo]

Bueller, Bueller, anyone?

[dwayneb236]

Ummmm, turning on the AC jump started the power converter?

I have no idea just throwing that out there.

[MacGumbo]

Originally Posted by dwayneb236

Ummmm, turning on the AC jump started the power converter?

I have no idea just throwing that out there.

Seems odd, I thought the same thing but why? I thought it might be a bad connection and the A/C vibration did it but I pasted all breaker contacts, even the 12v connections this past winter so that shouldn't be it.

[dwayneb236]

I'm sure someone MUCH smarter than me will eventually have a possible answer.

[pgandw]

The WFCO converters have a reputation of struggling to charge a deeply discharged battery (which you had). I have had that experience myself. When there is a load on the system, the WFCO defaults to 13.6 volts. Since it was ignoring the discharged battery as a 12V load, the 1st 12V load it saw was your use of the thermostat/AC control.

In my A-frame (I just wired in a new PD converter/load center last week), the WFCO wiring had a separate 10A circuit for the thermostat and perhaps some associated relays. The A/C will not work without this 12V circuit working.

Fred W
2014 Rockwood A122 A-frame