Community Forums

Plummit007 · 05-31-2023, 07:36 PM

Hello all!
I am a long time lurker to the forum, checking in from time to time, learning from a lot of very knowledgeable people and their experiences.

We have a '95 Winnebago Adventurer on the Chevy P30 chassis. We recently decided to update the wall sconces in the living area from incandescent to LED. After hooking the new lights up, they wouldn't work. They would quickly "flash" when the button is pushed, but wouldn't stay on.
I took one out and hooked it directly to a spare deep cycle battery in the garage and it worked fine.
I checked the power at the wires in the RV and read 12.7V. The battery in the garage read 11.7V.
After some head scratching, I decided to unplug the RV from shore power and the lights work fine, leading me to believe our inverter has fairly "dirty" output.
My question is: should I install a small capacitor on the power to each light, or would it be a better idea to install a larger one on the power output right at the converter?
In either case, does anyone have a recommendation for a rating on the capacitors I should use in each application?

Many thanks in advance!

shootist · 05-31-2023, 07:52 PM

It's your battery charger/converter side that's failing or dirty as you call it. Put your voltmeter on ac and get an idea how bad it is.

Plummit007 · 05-31-2023, 08:34 PM

Quote:

Originally Posted by shootist

It's your battery charger/converter side that's failing or dirty as you call it. Put your voltmeter on ac and get an idea how bad it is.

Thanks for the response! Are you saying I should test for a/c voltage on the 12v lighting circuit?

shootist · 05-31-2023, 08:41 PM

Quote:

Originally Posted by Plummit007

Thanks for the response! Are you saying I should test for a/c voltage on the 12v lighting circuit?

Yes, with the charger/inverter on, plugged in charging the batteries. It's commonly called ripple voltage. All converted ac to dc has a little

Plummit007 · 05-31-2023, 09:01 PM

Good to know! Is there an unacceptable limit to the a/c voltage present in the DC circuits that would determine the inverter/charger needs to be replaced?

sandwip · 05-31-2023, 09:35 PM

New converter/charger would have a smart charging system which is enough reason to upgrade. They are not overly expensive but are much better for the batteries. If you are having problems with the lights then it might upset the fridge as well. Had that issue.

shootist · 05-31-2023, 09:38 PM

Quote:

Originally Posted by Plummit007

Good to know! Is there an unacceptable limit to the a/c voltage present in the DC circuits that would determine the inverter/charger needs to be replaced?

You'll have to study that part. The inverter manufacturer is who I would contact.

OldWEB · 05-31-2023, 09:50 PM

Do you have the coach batteries connected? Are they in good shape? Cuz generally a battery is a good filter... so test it by connecting the new lights and turn off the shore power and run off of the coach batteries... monitor the DCV and then turn on the shore power again. Also, as mentioned, check the AC ripple on the DC, should be a very low number (unless the batteries are toast).
Also, the more load put on the converter/charger, the higher the ripple will be, so add as much DC load as you can to check ripple.

gpounder · 05-31-2023, 10:38 PM

I had a slight flicker when my magmun inverter/charger was in float mode. I think it samples the voltage to see if it needs to change modes. My cure was this very large DC filter.

jaydee325 · 06-01-2023, 05:39 AM

OP, please clarify if you have a charger/inverter or charger/converter.

Converters of that era were notorious for having a lot of AC ripple on the output. My 1995 motorhome had a converter and it output around 7 volts ripple. Electronics did not like that. To compensate, the power panel had outputs for DC from both the converter and battery. All that was needed to get clean power to the appliance was to move the wire in the panel from the converter side to the battery side. The battery will be the "filter" for the AC ripple.

Persistent · 06-01-2023, 07:22 AM

Some good advice posted above. Basically, technology has changed. New systems are better in multiple ways. New appliances are less tolerant of old technology.

The RV may have a two sided converter/charger. One side for battery charging. One side for 12 volt appliances. The side with the battery is probably clean. The battery stabilizes the voltage. The other side relies on a capacitor to absorb the ripple current.

Many old capacitor designs are subject to aging. Adding a large capacitor will help a lot.

However, as posted above there are multiple issues. Replacing with a new converter/charger will be heads and tails better for your system than the old one even when it was working as designed.

Olyteddy · 06-01-2023, 10:12 AM

You could also try different bulbs. Some LEDs have a diode bridge & a filter built in and don't care about polarity or AC.

spyderRV · 06-01-2023, 01:51 PM

It has been suggested batteries will supress inverter noise. I found that my inverter was creating a lot of noise on my batteries.

More info at this link, solved.

https://www.irv2.com/forums/f23/spee...ml#post2849614

dssl · 06-01-2023, 04:14 PM

If your house batteries were healthy they would be able to even out the dirty charger signal. A common symptom of a weak house batteries are flickering LED lights. LED lights are very susceptible to voltage fluctuations.

Make sure your batteries have enough water, maybe do an equalization charge. You probably need new house batteries.