Battery draining while connected to shore power

[Jfr]

Hello,
2019 Grey wolf 26dbh. Replaced original battery as it was dead, bought a good rv/marine battery, after 3 weeks attached to shore power the battery was only 1/2 charged. Took the inverter to have tested, it's fine. 40amp, 15amp and 10amp fuses are all good. Replaced anyway. Any ideas what I can check to see why it's not charging. I had the battery tested after I noticed it was drying and it tested fine.
Thank you all!

[tomkatb]

Need a voltmeter.

Battery reading 12.6 is 100% full. No shore power connection.

50% is 12.0 volts

Then plug in shore power. Battery will read 13 volts or more. Indicates the converter is charging.

It takes hours to recharge the battery.

[Jfr]

Thank you sir! Appreciate your response

[Jfr]

Originally Posted by tomkatb

Need a voltmeter.

Battery reading 12.6 is 100% full. No shore power connection.

50% is 12.0 volts

Then plug in shore power. Battery will read 13 volts or more. Indicates the converter is charging.

It takes hours to recharge the battery.

So, could I have been a little premature seeing the battery was getting low, and assuming it was not being charged? Guess I have never checked the battery when connected to shore power. Guess I always assumed it would be 100% all the time. Are you saying it normal to have the battery go down then the inverter will do its thing?
Thanks again sir!

[CHICKDOE]

A few comments.

It is the converter that charges a battery. It takes 120 volt ac power and converts it to 12 volt dc power to charge / maintain the battery.

An inverter yaks 12 volt dc from the battery and inverts it to 120 volt ac power to run things such as a residential refrigerator.

The converter and inverter may be separate units. Many converters are built into the power distribution center. Some are stand-alone. Then there are single units that combine both functions into a single box.

You need a multimeter (<$15 at Walmart). Takes dc voltage measurement at the battery terminals both when plugged into shore power and when not connected to shore power. You are looking for a dc voltage of around 12.6 volts when not connected to shore power and something like 13.2 or greater (up to about 14.4) volts when plugged into shore power.

What you don’t want is the same voltage reading both times. If you get this it indicates that the converter is not charging the battery. Note that I did not say the converter is bad. Simply the converter output charge is not reaching the battery.

How you proceed will depend on the readings you get.

[boondocking]

Originally Posted by Jfr

So, could I have been a little premature seeing the battery was getting low, and assuming it was not being charged? Guess I have never checked the battery when connected to shore power. Guess I always assumed it would be 100% all the time. Are you saying it normal to have the battery go down then the inverter will do its thing?
Thanks again sir!

No, the battery will not discharge if the converter is operating. Unplug from shore power and see if the interior lights work. If they don't work then look for one of these.

Should be less than a few feet from the battery on one of the battery cables. Look for a small reset button on it.

[Jfr]

Originally Posted by CHICKDOE

A few comments.

It is the converter that charges a battery. It takes 120 volt ac power and converts it to 12 volt dc power to charge / maintain the battery.

An inverter yaks 12 volt dc from the battery and inverts it to 120 volt ac power to run things such as a residential refrigerator.

The converter and inverter may be separate units. Many converters are built into the power distribution center. Some are stand-alone. Then there are single units that combine both functions into a single box.

You need a multimeter (<$15 at Walmart). Takes dc voltage measurement at the battery terminals both when plugged into shore power and when not connected to shore power. You are looking for a dc voltage of around 12.6 volts when not connected to shore power and something like 13.2 or greater (up to about 14.4) volts when plugged into shore power.

What you don’t want is the same voltage reading both times. If you get this it indicates that the converter is not charging the battery. Note that I did not say the converter is bad. Simply the converter output charge is not reaching the battery.

How you proceed will depend on the readings you get.

Wow! Thank you! Good information, I'm not great with troubleshooting electrical stuff, always stayed away as I don't want to fry anything, or myself. That sounds like an easy test. I do have a voltage meter that I bought after buying the camper. I'll give it a shot. Thanks again

[Jfr]

Originally Posted by boondocking

No, the battery will not discharge if the converter is operating. Unplug from shore power and see if the interior lights work. If they don't work then look for one of these.

Should be less than a few feet from the battery on one of the battery cables. Look for a small reset button on it.

I actually have two of those did not realize there was a reset button on them. I will look at them again, thank you!

[boondocking]

Originally Posted by Jfr

I actually have two of those did not realize there was a reset button on them

Most have reset buttons, some are auto reset, no button.

[Jfr]

Originally Posted by boondocking

Most have reset buttons, some are auto reset, no button.

No reset button, assuming maybe replace the two of them? There's a lot of wires going on there. When you are board and have time, can you explain what the purpose of those two are? If not I understand, thanks agai!

[boondocking]

They are there to cut the voltage off if the system becomes overloaded, just like your 120 breakers at home.
Do your interior lights work when you are not plugged in?

The way to check those circuit breakers is:
Use your voltmeter, check for voltage (DC volts) between the two lugs (with the lights turned on in the trailer). If there is no voltage then the circuit breaker is OK. If you do get a voltage reading then the circuit breaker needs to be replaced.

[kcmusa]

Do your lights work when not on shore power?

[TitanMike]

Originally Posted by Jfr

No reset button, assuming maybe replace the two of them? There's a lot of wires going on there. When you are board and have time, can you explain what the purpose of those two are? If not I understand, thanks agai!

Before replacing, look carefully at the ends of these circuit breakers. The reset button is usually very small compared to what one might expect. Look for something black, that might be slightly raised from the surrounding surface. Will be on an end and about 3/16" or so.

[tomkatb]

In the wonderful world of rv one must be handy!

40 years ago trailers often did not even have a converter or shore plug!

Today the modern rv has a bunch of stuff connected up that draws power from the battery all the time.

I really like the idea of a Bluetooth voltmeter connected to your phone. Mine has alarms so I know what is going on. $40. Mine contacts me daily to say everything is peachy. Set for alarming at 12.0 volts. Food for thought.

[hankpac]

Check the connections, are they tight, and uncorroded? (i know you just changed the batts), batteries full of acid?, all leads connected?, breakers and fuses all good?
Is the emergency break-away activated (sometimes when jacking up or for any reason, it gets pulled out, and locks up the brakes giving a hard load on they batteries)? Was the battery fully charged before connecting ( I usually hard charge them on my own battery charger before installing them). And of course, are ALL loads turned off? Lights, switches, ghost power (anything with a little LED), fridge, signal booster, Light in a storage bay, ANYTHING that could be draining as you are trying to charge.
Using a multi-meter is critical.
Good luck.

[bedubya]

Originally Posted by tomkatb

In the wonderful world of rv one must be handy!

40 years ago trailers often did not even have a converter or shore plug!

Today the modern rv has a bunch of stuff connected up that draws power from the battery all the time.

I really like the idea of a Bluetooth voltmeter connected to your phone. Mine has alarms so I know what is going on. $40. Mine contacts me daily to say everything is peachy. Set for alarming at 12.0 volts. Food for thought.

I beg to differ.

This photo was taken in 1980. It is a '78 or '79 Fleetwood Prowler Model 20J. It had a shore cord & converter. It also had a 40 gal. FW tank with a demand pump, 4 cu. ft. 2-way Dometic fridge, dry bath w/ small tub/shower, Dometic toilet with 30+ gal. black tank and 30+gal. gray tank.

You are right, though, in that it didn't have much in the way of stealth power thieves.

BTW, I pulled it with a '74 Ford Torino station wagon running a 351 Cleveland.

[Daniel.mullins4]

Get one of those cigarette lighter usb charge plugs with battery voltage reading, Amazon Dual USB Car Charger,4.8A Output,Cigarette Lighter Voltage Meter, check your converter specks for charging voltage steps, I have lithium so when voltage reads 14.6 battery must be low, 13.6 float, battery is full charge.

[AFDON]

The OP stated he replaced the original battery. For the first time in I don't know how long, nobody jumped on the reverse polarity fuses! Unless everybody is thinking the 40 amp fuses are the rp fuses? Anyway, without some voltage reading, we are all stumbling around in the dark.

JFR, please let us know what/why this is happening. It will be sure to help so one else.

[Jfr]

I really appreciate you all taking the time to respond to my post, I hope this is how I reach you all.

After reading all the awesome information you all gave me and while it was still warm enough here in Maine I reinstalled the inverter that I took to be tested. I brought my fully charged battery out and hooked that up.

I tested the battery and seemed to be fine. Before connecting to shore power I noticed that the usb chargers were working and certain lights would work just on the battery. I connected shore power, and the microwave turned on and the outside fridge turned on as I could hear the humm. I turned on every light including the purple LED lights inside the camper. (I have noticed that when those lights go on I hear the humm of the fan on the inverter) At this point I heard the fan kick in. I left every light, the radio, and the fridge on connected to shore power. It's been over 48 hours with temps in the single numbers and the battery is still 100% charged.

When removing the inverter I did make a mental note that one big ass wire did not seem to be tight. When I connected the inverter I made sure I tightened every connection and mad sure I could not pull the wires out. I also had to remove and replace the circuit board in order to get the - and + wires back in.

I am still connected to shore power right now to give it a few more nights, but I believe everything is working fine at this point. I wonder if that loose wire going into the circuit board was the issue?

When I went inside the camper today, the fan was running on the inverter, for what it's worth. Before removing the inverter to be tested I never heard that humm of the fan when turning stuff on, like I did during the summer.

Again, I hope this reaches you all and thanks again! I will update in a few days.
John