dimming lights

[beakyfudd]

While on vacation last week, I noticed the lights would dim if we had more than two of them on. The fan behind the breaker panel would come on, and the lights would brighten. When the fan went off, the lights would dim again. Any ideas "Montana masterminds"?

[bw2]

On my 3400, there are two 12v fuses for the output from the converter, I had one of the fuses that was blown and when I replaced the fuse, the lights were no longer dimming.

[Carl n Susan]

My less than educated guess is the battery is not well. The standard lamps (I assume you haven't changed over to LEDs) draw around 2 amps each (usually there are two bulbs per fixture) so you are sucking ~ 8 amps. That draw does tend to cause a slight dimming. The voltage will start dropping from 12.6V to lesser values (which is normal). As the battery gets depleted, the converter kicks in to re-supply it. The converter (the fan sound you hear is cooling the converter as it works) will put out over 13V which will brighten the bulbs. Once the battery is near full charge, the converter (and the fan) turns off until the voltage drops once again. And the bulbs will appear to dim as they are now running on lesser voltage.

In short, what you experience is normal, but I would have the battery checked to ensure it holds a full charge.

[exav8tr]

There you go, a possible solution!! Don't you just love this forum???

[NCFischers]

X2 on the battery.

[Ozz]

X3

[Exnavydiver]

Our bedroom reading lights would dim the overhead lights when we turned them on but that stopped dead when we shifted to ALL LED lights in the rig.. SWEET~!!!!!

[DQDick]

quote:Originally posted by Exnavydiver

Our bedroom reading lights would dim the overhead lights when we turned them on but that stopped dead when we shifted to ALL LED lights in the rig.. SWEET~!!!!!

X2 for us also.

[snfexpress]

I concur that your battery bank is probably bad. When a battery depletes to 10.5 volts you have a dead battery that usually won't take a charge.

I also think your converter should be checked. The fan only comes on when it gets hot. It is always "on" when hooked up to shore power so should be giving out about 13 volts even if you had no batteries. Now, this information concerns the OEM converters. If you have a smart charger, the voltage will vary depending upon the needs of the batteries. But, with a bad battery, the juice will get sucked from the converter making it work harder.

LEDs do help to keep your batteries from cycling, therefore increasing battery life. We've spent a lot of time and effort researching the benefits of constant current LEDs that work in our rigs. These are differ from automotive type LEDs that you can buy at the local auto parts store.

[beakyfudd]

Thanks everyone, looks like I have a few things to check. I replaced the battery a couple of years ago, so that should still be good. But I'll check everything.

[beakyfudd]

Oh, one other thing is, I keep it plugged into shore power whenever we are not camping. Do you think that is charging the battery too much?

[DQDick]

Have you been checking the battery water level. If you don't add distilled water every so often the battery will be in trouble.

[jackel1959]

As DQDick stated you need to check your battery water level. Depending on what type of converter you have (single stage or multi-stage) leaving the rig plugged in to shore power all the time can "cook" the batteries and deplete the water in them.

In our 2004 Mountaineer we had a single stage converter, left the rig plugged in all the time and I was adding water about 3-5 times a year. With our current rig, we still leave it plugged in all the time, but have a 3 stage Xantrex converter and add water maybe once a year and even then it is not much.

r,
Jack

[Tom S.]

quote:Originally posted by beakyfudd

Oh, one other thing is, I keep it plugged into shore power whenever we are not camping. Do you think that is charging the battery too much?

It shouldn't be. The 'newer' units like yours were supposed to have a sensor to monitor the charge and cut it back when the battery is full to a maintenance charge.

[drsmart]

On our converter there is a green led on the panel that indicates one of three modes it may be in. This from the manufacturer:

" The built-in Charge Wizard automatically selects one of three operating modes: BOOST, NORMAL, STORAGE.



BOOST Mode - Indicated by green LED remaining on. The output voltage is 14.4VDC to rapidly recharge the battery up to 90% of full charge.



NORMAL Mode - When the battery is between 50% and 90% charged, the green LED will flash once per second. When the battery has reached 90% of full charge the green LED will flash 2 - 3 times per second. In this mode the output voltage is 13.6VDC and the converter is safely completing the charge of the battery.



STORAGE Mode - Indicated by green LED flashing every 6 - 8 seconds. In this mode the output voltage has ben lowered to 13.2VDC, the RV battery is fully charged and the converter is maintaining the charge."

I believe you can push in the little button beside the LED to force the mode to change.

Dave

[Ozz]

A good battery check is in order, I would get those specific gravity checkers, a tube with little floating balls, check each cell and turn off the batter charger and check the volts with no load on the battery.

Good info: But it will make your head hurt...
http://www.phrannie.org/battery.html

[Thunderman]

As bw2 mentioned, the 2, 30 amp fuses....Change both even though they may not appear to be bad.

[beakyfudd]

Well, I haven't had much time to check things, but I found the water level in the battery was low, but still above the plates. I thought I would give it a chance to recover. I still need to check the specific gravity. I feel like an idiot, because I attended auto trade school and then worked on Mack trucks for 11 years and the sold Mac tools for six years. but I've been away from that for 18 years, and I'm a bit rusty. Where are the 30 amp fuses located, in the battery compartment?

[snfexpress]

The 30 amp DC fuses are in the converter. There are also, depending on your DC Distribution panel, 2 fuses in it for reverse polarity.

[beakyfudd]

Well, I checked the specific gravity of the battery, and it's at 1275 in all cells. The converter has two 35 amp fuses in the back, that are good. I believe all the conections are tight, so, a new converter seems to be the only thing left. I found the same converter on-line, that I have (55amp). Is there any value in getting a higher amperage unit?