What is draining our battery?

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LisaN

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Jan 24, 2018
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We have an old Lance Truck Camper that we use at the marina where we dock our boat. 

And something is draining our battery.  We are both long time RVers and we are just not getting what is going on.  Here is the scoop.

We hook up to shore power - our 3 way refrigerator works, our AC works and our sockets all work too.  But somehow the battery is either being drained fast OR it is not charging when plugged into power.  We also plug the unit into power when we are not using it (at my husbands yard - where he keeps all the trucks and heavy equipment for his business). 

When we are not using it the ONLY thing running that could be drawing battery is the 3 way refrigerator but invariably in a day or less the battery is drained and it won't fire anymore.  Even when we dry camped in the past with other units, we could go days on a battery charge. 

Oh and now the unit is winterized - we have a solar panel which trickle charges the battery and the 3 way refrigerator is shut off (the unit is not plugged in) - and after 2 months in the cold we still have some battery charge (there is a meter) of about 11.5 -- so we think maybe something is off with the 3 way refrigerator. 

Where should we start? Any ideas?  THANKS SO MUCH
 
It sounds a little like the battery is not charging, plus my guess is the battery is shot based on the fact that it has been fully discharged several times. It's a common misunderstanding when folks think 11.5v on a "12 volt" battery means it's almost full. Actually, a "12 volt" battery is 12.7 volts when fully charged. 11.5 volts represents around 10% charge, and is discharged enough (especially in freezing weather) that the battery is almost certainly damaged.

My recommendations would be:

1) Have a voltmeter handy
2) Buy a new battery, a deep cycle 12v. Check the voltage before installing, it should be 12.6-12.7 volts, if not take it back
3) With everything turned off in the camper install the battery and plug the camper in. Check the voltage at the battery, it should be about 13.5v or more. If it's more like 12.7 volts your charger isn't working. If so, immediately disconnect the battery to avoid discharging and damaging it.
4) If you are getting about 13.5 volts or more, then indeed you may have something discharging the battery

This should at least get you started
 
One thing you said was "OLD" OLD oftten means Magnetek  Series converter. Not a very good one.

Also how OLD is the battery. I mean 10 years with a GOOD converter is considered a long life.  one year with a Magnetek.
 
Agree with others on checking the battery and converter. Is the 3 way fridge running on 12 volt mode? If so, that would probably drain your battery fairly quick.
 
Thanks all --

So we did replace the battery this past fall because yes we knew it kept getting discharged and it is a deep cycle battery.

How do we check the voltage at the battery?  (my husband may know this answer but I don't)  I am betting he has a voltometer at his shop  -- and we started carrying a batter charger in the truck and re charging it all the time. 

I don't THINK the fridge is running on 12v mode - how would I know this for sure?  I expected it to be running on propane when we are travelling and on AC when we are on power.  My newer RVs just ran like that and I assumed this one did too. 

The Lance is probably late 90s vintage.  Other than this darn battery issue it is doing its job perfectly!
 
I would think there's a way to select what mode it's running on, but I don't know for sure. I've never used a 3 way fridge before. Just guessing here, but if no shore power, it may go to propane like a 2 way fridge, then if the propane doesn't light, it defaults to 12 volt. Hopefully the Wiz will join in on this topic and teach us all something.
 
LisaN said:
How do we check the voltage at the battery?
Click to expand...

With a voltmeter just check at the battery posts.

LisaN said:
I don't THINK the fridge is running on 12v mode - how would I know this for sure? 
Click to expand...

As kdbgoat says, you will be able to select the mode on the front panel somewhere. The first RV I owned (Class B Surveyor) had a 3 way, killed the battery routinely. 3 way fridges seemed like a good idea at the time but the current draw was so high on 12v that the 3 ways were abandoned and only 2 way fridges are available now. I would force it to run on propane (uses very little), then when you are plugged in manually set it to AC. I would suggest never using the 12v mode.

LisaN said:
So we did replace the battery this past fall
Click to expand...

OK that's good. Just be aware that even a new battery can be permanently damaged if it's allowed to go flat and not immediately brought back. Doesn't mean it won't work, but it may have diminished capacity.
 
kdbgoat said:
I would think there's a way to select what mode it's running on, but I don't know for sure. I've never used a 3 way fridge before. Just guessing here, but if no shore power, it may go to propane like a 2 way fridge, then if the propane doesn't light, it defaults to 12 volt. Hopefully the Wiz will join in on this topic and teach us all something.
Click to expand...

I had a 3 way. The fridge had a knob which we could position it to 12 Volt DC, gas or 110 Volt AC. It was right above the fridge door.
Something I would do before hooking up the cables to the battery, plug into shore power. Then check the voltage at both battery cables. This will tell you what the converter is putting out.
Then check the voltage of the battery before you connect the cables. Let us know what you get at both locations.
 
Thanks all! I will look for a selection switch or knob on the frig, though I really don't remember seeing it (and I have messed with the frig alot trying to figure out what the heck is draining the battery) -- that would be a boon if it was as simple as the darn thing running on 12 V when I didn't think it was!  I do think I may have the original book for it too. 

IF that isn't it we will definitely check the voltage coming in at the battery -- because it SHOULD continuously charge when plugged in right? 

Then to find the inverter!
 
The converter should continuously charge the battery, it's not an inverter.
 
LisaN said:
Then to find the inverter!
Click to expand...

You'll be looking for a CONverter not a INverter. Big difference.
A CONveter converts 110 Volt AC (Shore Power) to 12 Volt DC for nearly all your components. Lights, furnace, water heater etc.. 
A INverter converts 12 Volt DC to 110 Volt AC. Some people use these to power a residential fridge or a TV while boondocking.
 
OH Thanks for that clarification -- looking for the CONVERTER!! If that is bad, is it a costly item?  Though we love the old Lance, she is rotting around herself and I am not sure how many more seasons she will be with us LOL
 
Here's one of the top recommended places to get a new converter. If you give them a call, they will help you decide what is the best converter for your situation.

http://www.bestconverter.com/
 
Don't just get a voltmeter. You should get a DC clamp meter. They are cheap enough and they do all the things a regular voltmeter does plus you can measure DC current down to 10 milliamps or so by just clamp over the wire.

I got one months ago and you can isolate quickly what leg coming out of the dc panel is still drawing current and how how much.
In fact I've now labeled the on/off switches in my rig with the amps it controls. Most led lights are less than 200 mA. But I have a string of incandescent minilights that draws 12 amps.

http://www.uni-trend.com/productsdetail.aspx?ProductsID=712&ProductsCateId=773&CateId=773

You also can use it to clamp right on to the wires connected directly to the battery, it can measure up to 200 amps and tells you the direction of flow.

dale
 
So I just saw your post and if you haven't already figured this out I have some advice to offer. Disconnect the negative cable to the battery and put a 12 volt test lamp between the battery post and the cable end. If there is a drain on the battery the lamp will light. Unplug the 12 volt fuses 1 by 1 until the lamp goes out. This will tell you what circuit is drawing current. From there you have a good chance to narrow this down to a manageable conclusion. Best of luck.

PS the converter must be unplugged and everything off that draws 12 volts
 
Hi all .... it is finally spring.  So our refrigerator is in fact 2 way, so it is not trying to run on the 12v.. we are going to check the converter first ... our AC and 110 outlets work fine so we are getting 110 into the RV.  Maybe it?s just because of the lack of conversion we are getting the quick battery drain. I will keep you posted.

An incidentally the battery kept power with a trickle charge from the solar panel all winter.  It didn?t last through the entire ?raising? process of the truck camper though we had to give it more power.
 
Sounds like the CONverter is shot.  All the lights and such run off 12VDC, and the battery is not being charged due to the charger i.e/ converter being shot.  With everything plugged in, measure voltage at the battery.  Bad converter, voltage below 13.3V  Good converter, voltage above 13.5V.
Good Luck!
 
@grashley that seems most likely, can a fuse or tripped breaker in the converter be the culprit? It is a bear to check the thing out where it?s located but we will of course. 
 
At least in my FW, the converter is powered from the main breaker panel, so, yes, there is a breaker in the circuit.  There MAY be an internal fuse, but checking that requires accessing the converter.  If you check voltage at the battery and it tests bad, it may be worthwhile simply replacing it with a newer, improved model as mentioned by our resident goat.
 
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