We have a problem with our 07 Georgetown 350DS Class A Motorhome draining both the Starter Battery and the House batteries in a matter of 3 days. I can't figure out where the draw on the batteries is coming from. I just put in a brand new Starter battery because my old one (6Months) old would not even register on AutoZones battery meter, charger to try and bring it back to life... It was an Optima Red Top. Replaced under warranty. My house batteries are 2 Trojan T105 6V's. These are about 8 months old. We have been having this problem for almost 2 years now but have put a bandaid on it by keeping them both on a trickle charger to keep them full. So about 4 days ago I wanted to see how fast they would drain. I put the Schumacher Charger on the batteries and did a rapid charge on the batteries until they all showed 100% then waited until the next day and checked voltage. This is what I got.Day 1Starter 12.3vHouse 12.27vDay 2Starter 11.94vHouse 11.69Day 3Starter 11.20vHouse 11.41Day 4Starter 6.46House 6.44So you can see there is a consistent voltage drop from each day and major drop from day 3-4. I have no idea what's going on. To be honest this is actually pretty good because before I had an RV Mechanic tell me to turn off the Climate control Switch off in the Dometic Refrigerator my batteries would drain in about 12-16hrs to the point you couldn't even start the Motorhome without a jump. All these numbers are with the Dometic Climate Control switch off and it lasted a few days longer but something else is causing a drain on the batteries.Also when the RV is not being driven like now when I tested the batteries I have the House Disconnect switch turned on so everything should be disconnected.. Not sure where to go from here..Any ideas?

charge them up , if they will charge and then take off the neg cables at the battery. The voltage you post for day one show that the all battery are not fully charged 50%. Start them out at 10 amps till they are charged, 24 plus hours plus, then switch to 2 amps and finish them off. Could be another day, depend on the status of battery. Then remove the negative cables and check them in 12 hours plus. If voltage is falling then you battery have a low cells. With the cables remove easy to find which one is at fault. Then post back. A bad alternator diode can cause them to drain, stuck relays.

The Schumacher charger that I have only charges at 3amp 5amp or 20amp. Should I start the 6v and 12v batteries out at 20amp and go until full then go to 5amp then 3amp? Also I am going to unhook the 6v's from series and charge them separately. That way I can make sure each one is charged all the way. Since the 6v's are hooked in series to do the drain test on the 6v's do I just unhood the cable that goes from the Pos to Neg on the batteries? Or do I unhook the Ground and leave the +to- connected?

Also what should a fully charged 12V battery read when fully charged? I was under the impression that 12.3 or 12.27 that I got on the 1st day indicated a full charge. Also I am pulling all the batteries and charging them separately with no cables attached then will reinstall and put only the POS cable on correct?

How long have you owned this motorhome? Is this something that just suddenly started? I have a similar issue with my recently purchased motorhome and I think it may be a mis-wired after market radio that the previous owner installed before I purchased it. I'll find out in the spring when I take the radio out and check the wiring. I'm also wondering whether my non-functioning day-time running lights have anything to do with the drain on my starting battery. I have removed the battery and it does not go dead when it sits on the floor of my garage. The day-time running lights have a relay that I have been unable to locate and it may possibly be shorted?? Best of luck trying to figure this one out! In the meantime I have added a switch to isolate the house battery charge line from the starting battery so that both of them are not draining at the same time.

I had the same problem with a 2007 Georgetown 37TS and it was eventually traced to a mis-wiring issue that had the heated mirrors always on-Switch was Off but current was still always flowing at about 2 amps and killed the battery, Worth getting someone with a DC ammeter to measure current draw when supposedly everything is off and then just trace which wires have current flowing.Post if you need more details.

Major Battery Drain on 07 Georgetown Class A | Good Sam Community

14 Replies

45Ricochet
Explorer
Jan 30, 2016
MountainAir05 wrote:
lacofdfireman wrote:
Also what should a fully charged 12V battery read when fully charged? I was under the impression that 12.3 or 12.27 that I got on the 1st day indicated a full charge. Also I am pulling all the batteries and charging them separately with no cables attached then will reinstall and put only the POS cable on correct?

here is a chart

http://modernsurvivalblog.com/alternative-energy/battery-state-of-charge-chart/

CLICKY

Good chart. When mine are fully charged at rest both read 12.7
I personelly never let them get lower than 12.2
Letting them drop lower reduces life span.

But yes I believe you have a good draw on them cause they won't even fully charge.
4x4van
Explorer III
Jan 30, 2016
All good suggestions above, but... The one thing that hasn't been mentioned is the fact that the house batteries and the chassis batteries "should" be isolated from one another unless your ignition is on. Since they are both draining, even with the house batteries "turned off", there is something that is keeping them connected. So the first thing to check is the isolator (relay or?) system between the two to figure out why they are remaining connected. It's quite probable that that will also lead you to your current drain.
lacofdfireman
Explorer
Jan 30, 2016
Matt_Colie wrote:
There was a lot of boat work to do before the depression that still hasn't ended in Michigan. I often did this kind of trouble shooting and was regularly successful.

Start by taking a small 12V light bulb and attaching two wires with alligator clips. They don't need to be long. It is handy if you can put it somewhere that you can see it from the fuse panel.

Charge all the batteries and starting the house battery first, connect the little light in series with it. If it even glows, there is a drain. Start pulling fuses or popping breakers until it goes out. When I does, you have found the problem circuit.

Now the expensive fun begins. finding the actual location of a phantom load can be frustrating.

Matt

Wouldn't a test light do the same thing? Of course you would need someone at the test light telling you when it went out.
Matt_Colie
Explorer II
Jan 30, 2016
There was a lot of boat work to do before the depression that still hasn't ended in Michigan. I often did this kind of trouble shooting and was regularly successful.

Start by taking a small 12V light bulb and attaching two wires with alligator clips. They don't need to be long. It is handy if you can put it somewhere that you can see it from the fuse panel.

Charge all the batteries and starting the house battery first, connect the little light in series with it. If it even glows, there is a drain. Start pulling fuses or popping breakers until it goes out. When I does, you have found the problem circuit.

Now the expensive fun begins. finding the actual location of a phantom load can be frustrating.

Matt
rgatijnet1
Explorer III
Jan 30, 2016
Once you test each battery by itself, and see if it will take a full charge, you can hook one up to see if there is a drain with your system's electric or if one of the batteries was bad. There is no need to hook all of your batteries to do this. One battery will tell you if you have a problem.
Hook up the POS cable first and the NEG cable last.
MountainAir05
Explorer II
Jan 30, 2016
lacofdfireman wrote:
Also what should a fully charged 12V battery read when fully charged? I was under the impression that 12.3 or 12.27 that I got on the 1st day indicated a full charge. Also I am pulling all the batteries and charging them separately with no cables attached then will reinstall and put only the POS cable on correct?

here is a chart

http://modernsurvivalblog.com/alternative-energy/battery-state-of-charge-chart/
Ivylog
Explorer III
Jan 30, 2016
I'd start by removing every 12V fuse (one at a time) and using the 10 amp feature on even cheap Harbor Freight meters find the circuit that's drawing amps when it's supposed to be off.
rgatijnet1
Explorer III
Jan 30, 2016
All it takes is one bad battery, with a shorted cell, to drain all of your batteries. I would disconnect each battery and test them independently and see if you have a bad battery.
As you have seen, a bad battery discharges all of your batteries to that level so it may mean that all of the batteries are permanently damaged and may need replacement. Disconnecting them and testing them each by themselves is the only way to tell the condition of each battery.
Also keep in mind that during the Winter some people will use their outside mirror defrost and forget to turn it off. This has a big draw on the batteries and if they are drained too low, they may not be salvageable.
azrving
Explorer
Jan 30, 2016
One trouble shooting method would use a tool like This to isolate circuit draw. You can remove one fuse at a time and see the current draw on that circuit.

You could also use an amp meter in the whole system and start removing fuses one at a time until an amp drop is seen.
In theory if you had no test tools at all you could remove all the fuses and see if the excessive draw stops. From that point you could add one fuse at a time until the problem occurred again. That's very time consuming but it gives you the idea of what you are trying to accomplish. On the other hand this is no guarantee that the problem is in one of those fused circuits and someone hasn't wired something in directly. It's hard for anyone to give you an exact answer as it could be anything and sometimes it can be some very silly little totally unexpected thing.

It's a process of elimination so go slow and easy. Problems like this can kick your behind but in the end you will better understand you rig. If you are not used to doing this stuff be careful as fire and smoked wiring can happen if you short something.
snarley
Explorer
Jan 29, 2016
I had the same problem with a 2007 Georgetown 37TS and it was eventually traced to a mis-wiring issue that had the heated mirrors always on-Switch was Off but current was still always flowing at about 2 amps and killed the battery, Worth getting someone with a DC ammeter to measure current draw when supposedly everything is off and then just trace which wires have current flowing.Post if you need more details.