Charging system question

[withanh]

When we were camping last weekend, we had an issue that I think is related to the charging system, and I'd like some ideas and suggestions.

We were plugged in to 30A shore power, but we noticed that the lights and heater fan would speed/brighten up then down then up then down. Some investigating showed that when in a down cycle the control panel (that shows tank & battery fullness levels) would not show as charging, but when the lights and fun were in an up cycle the control panel would show as charging.

We initially thought it was the shore power dropping because the campground had just winterized most of the sites, but the clocks on the micro & radio did not drop so I'm relatively certain the shore power was not dropping.

Thanks for any ideas, thoughts & suggestions!

h

[John Hilley]

Check all the battery connections and make sure your grounds are clean and tight. Could also be that the campground was experiencing a "brown out" and not dropping completely.

[withanh]

Replaced all the cables & batteries this summer and am sure they are solid, but will double-check. Also forgot to mention I put in a battery cut-off as well.

Don't think it was the campground, my sis was in the next spot and did not have any issues with power, that's why I thought it was mine.

I'm also going to power everything up here at home and see what happens with the power, just haven't had time yet.

Thanks for the reply!

[wa8yxm]

Well for some reason your converter is cutting in and out.. Now, this can be caused by a self resetting circuit breaker in the converter output cycling due to overload, or several other things.. A common cause of this is a shorted cell on a battery.

[withanh]

I don't suspect overload, although I won't rule it out. The only load was the heater/fan and a couple of lights.

Say more about the shorted cell on the battery. I'm not super familiar with battery technology but these batteries and cut off switch are about 6 months old and we have been out a few times with no issues until this most recent trip. How do you check for a shorted cell in a battery.

I have two batteries connected in parallel. To me, that means the batteries are connected pos to pos and neg to neg, battery 1 pos goes to the trailer system and battery 2 neg goes to the trailer system.

[RV Roadie]

Mark Nemeth has a good page on testing your batteries here:
The 12volt Side of Life (Part 1)

For the more in depth one to print out I use Phred Tinseth's poop sheets here:
Batteries -- and Other Electric Stuff by phred

The completer poop sheets list is here:
Poop Sheets by phred

I would not worry about the electrical advice being from 2002 as the physics hasn't changed since then.

Hope that helps.

[tvman44]

Either bad connections in your 12 volt system or a converter about to die.

[huronwoods]

A few years ago, I had a converter in a Keystone Laredo do this. It turned out that the problem was a cooling fan in the converter which had become unplugged (from road vibration?). This caused the converter to overheat when load demand was high (lights, furnace fan), and the converter would shut down because of a thermal limit switch in the circuitry. When things cooled down, it would restart. I put a dab of silicone sealant on the connector, and never had the problem again.

[gonzo136]

Originally Posted by withanh

Replaced all the cables & batteries this summer and am sure they are solid, but will double-check. Also forgot to mention I put in a battery cut-off as well.

Don't think it was the campground, my sis was in the next spot and did not have any issues with power, that's why I thought it was mine.

I'm also going to power everything up here at home and see what happens with the power, just haven't had time yet.

Thanks for the reply!

On my motorhome when the shore power drops below 104v AC my surge protector shuts shore power off then it automatically restores shore power after a set time. When shore power is gone the inverter is no longer charging the batteries. Instead it is drawing power from the batteries which might slow down some 12v items (the heater fan for example). When it restores shore power the reverse applies. My surge protector will keep switching shore power on and off until I switch the shore power off manually. Don't know if maybe you have a surge protector and Sis does not have one? Something to check.

[withanh]

I'll check that Tony, but I don't think that's it. I'm certain my shore power was not dropping out, the clock on the microwave never reset and the micro has never worked unless connected to shore power so I either don't have an inverter or the micro circuit isn't on the inverter.

I'll just have to knuckle down and do some testing/troubleshooting tomorrow.

Thanks everyone for the great suggestions and links, I'll report back with my findings.

[withanh]

Looks like it's definitely something on our end. And it's definitely the charging circuit, we're on shore power and it's doing the cut-in/out thing still. Guess I have some serious troubleshooting ahead of me.

[withanh]

A little ray of sunshine in all this, I was going through our paperwork to pull up any wiring schematics, etc. for me to use in tracing out the electrical system and found the extended warranty that we bought covers the electrical, including chargers, inverters, converters, etc. And it's good until Nov 2012. Sounds like my work here is done :-)

[mgscott4]

I had the same problem, my converter would cause my lights to brighten for about 5-10 seconds then dim for 10-15 seconds then brighten again repeat. I could hear my converter fan come on when the lights were bright and go off when they were dim. My converter was bad. I changed it and everything works good.

[RV Roadie]

If you get the converter unit replaced make sure you get the upgrade to the electronic converter instead of the linear one used most often. Even if you have to pay a bit extra it is worth it.