Skip to main content ↑ ↓
Topic: Batteries not being charged when on 120V (Read 603 times) previous topic - next topic

Batteries not being charged when on 120V

Went camping for almost two weeks.
Found out both the coach and the engine batteries were not being charged while plugged into 120V/50A or 30A.
Start the coach and the alternator quickly charges both batteries up to 13.4 or even 14.3
The Dometic fridge would only work on AC power---until coach and engine batteries are fully charged.
Is my power unit/convertor gone to hell? I checked the fuses and they are OK.

Re: Batteries not being charged when on 120V

Reply #1 –
On my coach, there is a "charger" circuit breaker in the AC breaker panel, non inverted side. Not sure about your '89 but since it is serviced by AC one would assume there is a breaker somewhere. Your start battery will not charge unless the boost switch is on or the engine running.

This is also assuming you are getting AC to everything else in the coach.

Re: Batteries not being charged when on 120V

Reply #2 –
Most of the older coaches with original  inverter/ chargers do not charge the engine batteries.  If your batteries are not being charged or keep fully charged when plugged it, it could be charger not getting 120V power or that it decided to exit.

Re: Batteries not being charged when on 120V

Reply #3 –
Norm, do you hear a "thump" when you plug into shore power? I had a similar issue a while back and it turned out to be the 50 to 30 amp adapter. No voltage on one leg. I would start at the shore power cord
PS, be sure the Boost switch on the dash is engaged to charge both batteries, but I'm sure you already know that. Good luck!!!

Re: Batteries not being charged when on 120V

Reply #4 –
Thanks guys. Here is what I tried while camping. First week (boondocking) using my portable 2500W generator and the noisy Onan onboard generator.
"Thump" is present when firing either generator. Boost switch is in charge position. Still no battery charging.
Tried hooking my portable generator to the charger in the "dump" compartment. Still no charge. The two fuses on the charger face were both good. New charger put in when we bought the coach--about 8-10 years ago.
Later, after boondocking at Day Lake in N. Wisconsin, we moved to Chippewa Flowage and had 50A shore power. Heard the "thump" but still no charging of batteries.
Luckily, my HF 100A solar panels worked at charging the engine battery. I have rigged the solar output so I can switch to  charge either battery. LOTS of trees still with leaves so power was iffy at times.
I would start the coach engine if battery charge levels got down to 12.6 V.
Also, strange thing happened. The Dometic three way fridge (new in 2009 by previous owner) would only work when getting 120V.
Got home after driving for about 3 hours and now batteries fully charged and the fridge automatically switched to GAS mode of operation. Plugged in here at home and back to Auto and AC operation. Apparently 12V only works if battery is fully charged.

Oh, priorities had to change around 3:45. The DW fell coming out of the coach (arms full of stuff) and landed on right elbow on the asphalt, slammed her head on the propane compartment door. Seems right foot doesn't like to let left foot push it over so it fought back and DW lost. We got home from Emergency Walkin at the hospital at 9:45  last night.
No breaks, but lots of aches and badly swollen elbow and headache with very sore neck muscles on her right side.   
By the way. I checked the coach, and it is OK. Not even a scratch!! Tough coach.                                   

Re: Batteries not being charged when on 120V

Reply #5 –
Darn it! Please tell Mrs. Norm that our thoughts and prayers are with her for a speedy recovery.
There is a discussion on how to check the converter output, etc. I will try and find it and send you a link.
Until then.....

Re: Batteries not being charged when on 120V

Reply #6 –
OK, Norm. Probably the best way to get you started on checking out your converter is to go into the Forum and Tech Talk, and from there search for "Power Converter".  Tons of info there, and way too much to try and pass on....
Please advise on this as to your fix, and, again, tell Mrs. Norm to Get well soon!!!!!

Re: Batteries not being charged when on 120V

Reply #7 –
My DW Mary is tough. We didn't get to be almost 80 by being wimpy.
When one becomes a klutz, one has to be tough!!

Re: Batteries not being charged when on 120V

Reply #8 –
"Dumb" converters are pretty simple...  They either work, or they don't work.

Is your converter plugged into a regular duplex outlet, or is it hard wired?  Does it have a "ON-OFF" switch?

If plugged into an outlet, do you have power at that outlet?  If not, find the circuit breaker for that circuit and reset.

Is there any kind of circuit breaker reset button on the converter itself?  If so, is it popped out?

The converter output cables connect to one of your house (coach) batteries.  Are the (battery end) connections clean and tight?

If all the above checks out good, then time to shop for a new converter.

Re: Batteries not being charged when on 120V

Reply #9 –
Check for 110V at the plug the converter plugs into and then 12V plus coming out of the converter. They will usually have two fuses so check those. I don't ever use the boost switch as it uses too much juice, gets hot and if the shore power fails, it will ruin both sets of batteries. As I have posted before, I just run a double fused jumper between lighter plugs and it keeps the AGM house and conventional engine batteries charged. I unplug before I go anywhere. Has worked perfectly since we bought the coach in '08.

Since we are rarely plugged in once we leave the house, the solar combined with the jumper keeps both battery sets charged at a campsite.

In case you need a new converter, Progressive Dynamics makes an excellent converter as seen in the Amazon reviews. Our new one keeps the voltage right around the advertised 13.2V. It does have a conditioning phase every 23 hours or so where the voltage is raised for 15 minutes to combat plate sulfation. Since our AGM caution against it, I called PD but they said it was too short in duration to damage the AGMs. Most AGM brands approve the conditioning.

Photos is of the twin voltmeters, house and engine batteries and the jumper. The white specs are ash from the River Fire. Voltage is after installing the new PD converter.

Pierce

Re: Batteries not being charged when on 120V

Reply #10 –
What make/model of inverter is in your coach?  I know there is a setting in my Xantrex SW3000 control panel to turn off charging.

Re: Batteries not being charged when on 120V

Reply #11 –
If OE, it is likely a CONVERTER unless Norm or a previous owner added an inverter or inverter/charger.

Re: Batteries not being charged when on 120V

Reply #12 –
I will have to go check---later--thanks.

Re: Batteries not being charged when on 120V

Reply #13 –
Quote from: WS6_Keith –
What make/model of inverter is in your coach?  I know there is a setting in my Xantrex SW3000 control panel to turn off charging.
Looking at the year of his coach, he will probably have a Taytronics 1500 watt inverter in the compartment by the entry. The converter (no inverter fitted) is probably located close to the electrical panel on the opposite side of the coach.

Piere

Re: Batteries not being charged when on 120V

Reply #14 –
Sorry Pierce, but wrong guess.
When we bought the coach King's Campers had to replace the old  power supply.
They installed a Parallax Power Supply unit 7400 series Converter/battery Charger.
Serial #R09400080
So how do I tell if it is functioning correctly? The fuses are good (I checked)

Re: Batteries not being charged when on 120V

Reply #15 –
Quote from: nitehawk –
So how do I tell if it is functioning correctly? The fuses are good (I checked)

Easy.

Let house battery run down some (confirm voltage at the battery under 12.5 VDC).

Plug into shore power or turn on the generator.

Recheck voltage at the house battery bank.  Should be over 13.2 VDC and with a smart charger, will probably be closer to 14 as it starts in bulk mode.


 

Re: Batteries not being charged when on 120V

Reply #16 –
While plugged in, if it's not working the voltage will NOT be over 12.6. If it is working it will be higher than 12.6, usually 13+ as stated.