12 volt lights flicker/water pump pulsing

brittsnbirds · 09-17-2023, 07:33 AM

I own a 2014 Keystone Sprinter. I've noticed in the past year that the 12v lights flicker as well as the water pump pulses when plugged into shore power. The converter(?) sounds like it is cycling when the lights flicker. When I disconnect the shore power and run only on 12v flickering stops. My battery is only a couple of years old, Superstart Marine Deep Cycle 27DCM. When I check the voltage at the battery (disconnected) it shows 12.52 volts. The reading on the terminals going to the battery (disconnected), from the converter is 13.7 volts. My biggest concern is the converter is bad but from reading previous posts it sounds like the battery is bad.

Haven't taken the battery to O'reilleys to have it tested yet.

Thoughts? If the battery is bad any suggestions for a "better" replacement?

Pat

**JRTJH** · 09-17-2023, 08:03 AM

I'd have the battery tested before blaming the converter/charger... A shorted cell will cause the converter/charger to "cycle" which can cause the problem you're seeing with flickering lights and "pulsing water pump"... What happens is the converter/charger is trying to charge the battery and when it detects the shorted cell, it breaks power (cycles power from the battery). That causes the voltage in the converter section to go up and down which you see by flickering lights and variable voltage to the water pump....

I'd first verify the battery is good. If you don't want to take it out and go get it checked, just disconnect it from the trailer (so only the converter/charger is supplying power to the lights and water pump) and see if the pulsing pump and flickering lights work properly. If they do, you know it's the battery overloading the converter/charger. If they still flicker and pulse, then I'd look at the converter/charger, but I don't think that's your problem. My bet is on a bad battery cell.

Just remember, don't extend/retract the slides, use the landing gear or deploy the awning without a battery attached to the system..... (follow that red sticker next to the control panel for the slides and awning)....

brittsnbirds · 09-17-2023, 09:16 AM

Thanks for the prompt reply John!

Had the battery tested at OReilleys, they stated it was good 12.5 volts, he used a hand held big tester with a few buttons and waited for it to do it's thing.

I didn't put the battery back in, isolated the + terminal to prevent a short. Made sure nothing was turned on inside. Turned the shore power on and some of the 12v lights. Very dim but not surging or flickering. Turned the water pump on still no pulsing.

Just wondering if the battery testing wasn't sufficient??

Your thoughts?

LHaven · 09-17-2023, 09:29 AM

In a pinch, I suppose you could swap in a known good battery from another vehicle just to do a short test. It should have plenty of capacity just to run lights and a water pump smoothly.

bobbecky · 09-17-2023, 10:15 AM

Before you do anymore testing, remove the cover on your inside electric panel, with the shore power disconnected, and tighten all the screws on both the 12 volt DC and the 120 volt AC connections. It sounds like you might have loose connections causing the flickering.

brittsnbirds · 09-17-2023, 10:33 AM

Thanks bobbecky didn't think of that but should have considering this thing gets the crap shook out of it!!

Per LHaven's suggestion I pulled another vehicle up close and disconnected the battery, hooked some heavy weight jumper cables to the +/- terminals on battery then to trailer. Turned the juice back on. Viola the 12v lights are bright, water pump doesn't pulse neither does the converter.

It's been a while since I've seen the 12v lights so bright. Moral of the story? New battery will be purchased.

Any recommendations on brand of battery to get as I do not want to get what I had?

Thanks guys for talking me through this adventure!!

Pat

**chuckster57** · 09-17-2023, 03:26 PM

If you have the room, now is a great time to upgrade to a pair of golf cart 6V batteries wired in series.

brittsnbirds · 09-17-2023, 05:39 PM

Good to hear from you chuckster57!

Thought about it but don't have the room, due to the lack of storage in my Sprinter. Thinking about dumping the wet cell and going with an AGM. Is there a particular AGM that you would recommend?

Pat

**chuckster57** · 09-17-2023, 05:47 PM

I’m not a big fan of AGM. I had a pair of optima blue tops at one point, didn’t seem to last long.

**sourdough** · 09-17-2023, 05:59 PM

Quote:

Originally Posted by brittsnbirds

Thanks bobbecky didn't think of that but should have considering this thing gets the crap shook out of it!!

Per LHaven's suggestion I pulled another vehicle up close and disconnected the battery, hooked some heavy weight jumper cables to the +/- terminals on battery then to trailer. Turned the juice back on. Viola the 12v lights are bright, water pump doesn't pulse neither does the converter.

It's been a while since I've seen the 12v lights so bright. Moral of the story? New battery will be purchased.

Any recommendations on brand of battery to get as I do not want to get what I had?

Thanks guys for talking me through this adventure!!

Pat

The battery you need/use depends on how you camp. If you never camp off grid you don't need the capacity of 6v batteries etc. The RV comes (generally) with one 12v marine/rv battery that gets a person by. Depending on how you camp that may be adequate (I always have 2 and don't boondock anymore) or other options may need to be considered.

In the old days I had 1 12vdc battery and you just dealt with it. Then we got a generator and we could go anywhere and do anything seemingly. Then we got older and although we have a generator we don't stay anywhere without full hookups. A 6vdc setup would not benefit us nor warrant the new boxes etc. That said, you're particular situation and preferences completely dictate what you need/want. Once determined you can then focus in on the type of battery that would best serve the way you camp.

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