Why does converter run constantly?

[JRS514]

Bought my 2006 Cougar in May of 2013. The converter ran only when using some appliance or lights. Just came back from a week vacation and the converter ran non-stop, even when I shut off anything that would draw power.
When I got home and connected the electricity, everything works and the converter is not running? What's up?

[hankpage]

I would take a guess that your battery was low and being charged. After the trip and the time coming home it is back up to full charge and the converter is just maintaining. What you hear is not the converter but the fan cooling it when needed. JM2¢, Hank

[leonandlisa]

This is just a guess, but when you were camping even when you shut everything off the converter still has to recharge the batteries from previous use. After your drive home the batteries where charged by the tow vehicle on the trip so when you plugged in the batteries were already topped off so they weren't calling for a charge.

[WaltBennett]

Like previous folks have said, your converter does two things - charges your batteries when plugged in and also converts 120vAC to 12vDC for whatever needs it if the batteries can't quite do it. Ours kicks in even when the batteries are charged and I'm moving the four slides or landing gear.

[Fastback]

Keep in mind that a converter only puts out very low amperage for charging. You tow vehicle probably put out 100 amps or more. So when you are towing the trailer with no draw it will completely charge in no time.

Paul

[JRS514]

Just installed two Brand New AC/Delco batteries prior to trip. As well it was a relatively short trip, only 2 hours.

[SAD]

Keep in mind that a converter only puts out very low amperage for charging. You tow vehicle probably put out 100 amps or more. So when you are towing the trailer with no draw it will completely charge in no time.

Paul

Incorrect. While the alternator may be capable of putting out 100-180 amps... The charging circuit in your tow line is limited to the fuse in that line. Likely 10-20-30 amps. Given the length and size of that charge wire, the charging circuit a effectively does little more than "keep alive".

[Fastback]

Thank you for the correction. I do believe that the charging circuit in the converter is continuous and not automatic. Once a battery is fully charged the amperage output is reduced but shut down. I believe it is a float mode.

Paul

[SAD]

Thank you for the correction. I do believe that the charging circuit in the converter is continuous and not automatic. Once a battery is fully charged the amperage output is reduced but shut down. I believe it is a float mode.

Paul

Correct here. Most modern "smart" converters have 2 or 3 stage charging.

The fan the OP is hearing is load defendant. Can come on when the charger unction is essentially not being used... And the remainder of the draw on the converter (12v lights, 12v appliances/fans) is enough to build up heat.

12 v light are the biggest draw (cumulative).. After switching to LED lights throughout the entire RV, my fan has simply not turned on once..

I can turn every single light on (interior, exterior, basement, water works, etc) and the fan doesn't come on. Not enough draw! I'm loving it.