Testing for Battery drain

[Oz]

Sent: 1/30/2006

I went out to start the rig today and the engine battery was stone cold dead.  The house batteries are fine.

How do I test the charging system going to the engine battery?

I don't have a MOM switch.  It's been disconnected but, there is an isolator and all the connections are there.  There is this toggle switch on the dash that I don't know what it's for.  It's located next to the old MOM switch so, I have a feeling it was a replacement for it.  This switch returns to the center position automatically whether you flick it to the left or the right so, I think it might be used to switch charging between the coach and engine batteries. 

I was flicking these unmarked replacement switches (and a button) trying to find out which one activated the windshield wiper.  I found it and the button operates the washer.  In the process, I flicked the mystery switch both ways so, if it controls the charging between the batteries, I may have switched it to charge the coach batteries and my engine battery ran dead.

I am charging the engine battery now with a shore charger.  Once it is fully charged, how do I check to see if this switch controls which batteries are being charged and how do I test to see if there is a drain on the batteries from somewhere?

Please keep the process like me:  stupid simple so I can understand it.

[Spudboy]

Sent: 6/21/2004 

SOB:

This is an ongoing problem for the Spudmobile as well.

Recall, I am the rig with two isolators? Yeesh. Everytime I go out to start my rig the engine battery is dead. Although less often after the following checklist.

So...I always do the shore power recharge thing about two days before I go. I also installed a cut-off switch (used to have one that was a knife switch on the engine battery negative terminal, but that was hard to use so I wired one up to a toggle switch on the dash) this seems to have slowed the engine battery drain while traveling: when we are stopped for the night, I cut-off the engine battery, hoping to retain charge/minimize mystery drain.

I have a MOM switch, and my coach batteries seem to hold a charge for a long time. When I start up the rig, I usually have to rock over to dual for a cold start, remembering to turn on the engine cut-off switch first...I am guessing your toggle switch that returns to center is a replacement for the MOM switch which, if mine is any standard, can become not-so-reliable with age and dust.

Confused? I also carry two spare batteries that aren't hooked up to anything but my shore powered trickle charger. That way, I am sure of some extra juice to get Spudmobile started and home.

What I really want is a good friend who is an automotive electrical wizard to fix my system for no money so I can use my generator to charge all my batteries and why couldn't the alternator charge them all while running, and why don't I have the money to get set up with solar panels so I never have to worry at all?

FUEL CELLS...that's the answer!

- Spudboy (fuelishly selfish)

foolishly shellfish?

[Jupp318]

Sent: 6/21/2004 6:17 PM

Hi Guys,

  It sounds as if you both have something draining the battery whilst you are not running.  To test this you need a meter.  Set your meter to read DC Amps, disconnect the +ve lead to the battery and connect the meter between the disconnected lead and the battery terminal.  If the meter reads anything then you have a discharge problem.  The trick is then to check that nothing is still switched on.  Generally think of anything that isn't working quite as expected and disconnect it, keep going until you find what makes the meter read zero.  It would be a good idea to disconnect the clock first as that is on all the time (if you have one!).

Happy hunting

Ian...

[enigma960080]

Sent: 6/21/2004

Sounds like a  shorted  diode in the  alternator   Disconnect  the  output  lead  from the  alternator  and  check  for  drain at the  battery.  if the  drain is  gone  you know whats next....
OR   drive  the rig to your local autoparts store  that  does  on-thecar testing  and  have them  check the  alternator....My  house  batteries  usually go down  after a while  but thats  usually  due to me  not turning off a closet light  or  info panel....

[Oz]

Sent: 6/22/2004

I charged the battery last evening and the rig started.  This morning, I tried it and the starter clicked like crazy but wouldn't engage.  That sounds like a drain to me! 

Ian,

     How do I put the meter between the lead and the battery?  Touch both with the red one and put the black one on a ground?  If I have no juice in the battery, how will a draw register?  I'll need to recharge the battery first and then check it, no?

[Jupp318]

Sent: 6/23/2004 2:25 AM

Hi Mark,

  Disconnect the +ve lead then put one meter lead on the battery and the other on the battery lead putting the meter in circuit.  Make sure the meter is set to DC Amps this normally means pluging the red lead into a different place on the meter.  The battery should have enough charge in it to show the drain but not enough to start the ol' girl.

Cheers Ian...

[Oz]

Sent: 6/25/2004

I'll be testing the system later this morning but, there was something very odd I totally forgot about... when I was charging the battery in the rig, initially, the needle on the charger went to number 8 on the yellow (charging) side of the meter.  Through about 3 - 4 hours of charging, the needle never moved!

I got another battery I've had sitting for a year, connected, from another vehicle.  It actually still starts the vehicle just fine, BTW (it's a CAT).  I took it out and put it on the charger out of the vehicle to see if the charger might be bad.

The needle moved to the same place, initially.  After 2 hours, it had moved to 2 on the green (charged) side of the meter so, I figure the charger is OK.  20 minutes later, the green light indicating full charge came on and the charger shut off.

I think this is a strong indication that the battery in the rig has bit the dust since it wouldn't take a charge.  I'm going to put the CAT in and test the system as suggested. - Sob

[Sea Hag]

Sent: 6/25/2004

A CAT ?  Hey Boo Boo !! I think Sob has you cat!

[Oz]

Sent: 6/25/2004 

DARN!... I've managed to keep it this long without him knowing and now, I've left the CAT out of the bag!  Oh, well.... in about a half hour, the CAT will look more like a fusible link... 
- AnonySob

[HeavyHaulTrucker]

Sent: 6/26/2004

Sob, I hate to suggest this -- it is something so stupidly simple and basic.  Have you checked the brake lights, to see if they are on when parked?  I recently discovered that the two springs on my brake pedal linkage are weak, and they do not let the brake linkage come far enough into contact with the switch plunger to shut the lights off unless I pull up on the pedal with my foot.

Like I said, I hesitated to suggest this -- but I guess mine has been doing it ever since I got it, and I never noticed it until some trucker asked me on the CB if I had LED lights or just a stuck brake switch (the LED lighting is about 4 times as bright as incandescent).

John Smith

[Lefty]

Sent: 6/26/2004

Heavy Haul, I had the same trouble with "Beatrice" when we owned her. I had to always check the taillights when we parked, and pull the pedal up. I also had to pull the pedal up after applying the brakes when driving. A larger spring cured it. Lefty

[Oz]

Sent: 6/27/2004

Very interesting observation and, isn't that just the sort of thing you'd expect from these tempermental old Winnies?  I always do a walk-around after shutting the rig down and the brake lights operate OK.

What I did find though was that the old battery was the culprit.  I haven't tested it yet but, I'm nearly certain it has a dead cell.

I ran the rig on BooBoo's CAT over the weekend trip, including running the radio for a couple of hours, blaring loud, while the rig was turned-off and... all is well. 

I did meet a very nice fellow with a Southwind, just down from us and he's been trying to track down an engine battery drain for the last 2 years so, Spudboy, you are not alone!  This fellow carries a spare battery and uses one of those dash-board, cigarette lighter plug-in, solar rechargers from Harbor Freight (about 10 bucks) to keep his battery charged.

Seems I've been having a run of good luck this year as compared to last year, no?

[Oz]

Sent: 6/27/2004

I also apologize for posting this question as it is pretty well covered in the "Smart RVing" resource I refer to all the time!

[mightybooboo]

Sent: 6/30/2004

SOB, would  you be so kind as to FedEx my cat  home when you're done with it?
BooBoo

[Oz]

Sent: 6/30/2004

Cat?  Cat??  Did I say Cat?  I meant "BAT".  Yes, that's what I meant!  A Battery Alternative Termolator.  That's it.  It's new technology.  I developed it myself.  It's stuffed with fur balls.  Holds electricity a real long time it does.  Sorry buddy, haven't seen your cat.  Might be hiding in your cattery box.

[Oz]

Sent: 7/1/2004

The field test reveals that I do in fact have a battery drain.  I put the voltmeter on the positive lead and post as Ian suggested.  Depending on how I set the meter, I had small, positive numbers showing, negative numbers, and no numbers so, that's when I decided a field test would tell for certain.  I know how to set the meter to see if it's reading 12v but, when it comes to amps and such.....

The toggle switch on the dash appears to be a battery/charging condition switch.  It does nothing when pressed to the left.  When pressed to the right, the needle jumps to the top of the scale... like 16v?!  The OEM battery gauge always seems to read just at 12v.

I'll be carrying a spare battery and charger until I hunt this down.  A fully charged battery seems to carry me for about 3 days or so.  As long as the alternator is working, at least I can keep running down the bum-fault.

[Oz]

Sent: 8/8/2004

After returning from the MACWJ, I totally forgot to disconnect the battery.  After about 4 days, I remembered.  I figured it would be totally dead so, I charged up the spare battery so I could switch it this past weekend (2 weeks later) for our trip to Gettysburg Farm ODW.

On a whim, before swtching the batteries, I tried starting the rig... and it started!  I have no clue as to why.  The battery in it is the same one which went dead before and I tested for a drain and got a low amp draw.  The only difference that I can possibly think of between now and the times it went dead is that I was running off the aux tank when I shut it down when the draw was present and I was on the main tank when I shut it down after Williamsburg and going to the ODW this weekend (it started fine after sitting 3 days there too whereas before, it would have been dead).  The aux tank fuel gauge doesn't work so, I don't know if this has anything to do with it but, I think I might try switching the fuel tank control and test for a draw and see what happens.

[denisondc]

Sent: 8/9/2004

I have to disconnect my Winnys engine battery, or have it go dead in about a week or 2. I havent found any specific cause either - and have come to the conclusion there may be a slight drain by way of some deteriorated insulation. Until I stumble onto the cause, I try to remember to disconnect the battery when Im not using it. This is seldom a problem, since when we get home from a trip and I need to drive to work, I have to take the battery from the winny and put it back into my daily commuter car.

[MSN Member]

Sent: 8/9/2004

I had the same problem with my 77 Chieftain. It might be your starter or if you have any accessories plugged in.

[Oz]

Sent: 8/9/2004

Rick, I followed the same procedure with an ammeter or ohmeter, or whatevermeter.  I did find a draw as posted above.  I hadn't started pulling fuses yet since I could disconnect the battery when not in use and only connect it to drive it.

P.U.M, A new alternator was installed last year and I put in a new HD starter well before the problem started.  Not discounting these items though, I just haven't gotten to checking it out since I'm having too much fun enjoying it right now!  And, there are definitely no accessories plugged in.  So, since it hasn't died completely, I've been putting my energies into other things... for the moment.

This latest turn of events is a real twist though.  I could count on the battery being dead within 2 days before.  Now, it doesn't die, or even cause the tell tale rapid clicking of the starter, in 2 weeks.  So, either something is bumping loose and then back again or, it's related to the fuel tank switch-over circuit and, I doubt it's the same problem you have, Rick, since yours seems to be constant. 

When I do check, I will post the findings, starting with the fuel tank switch-over circuit.

[HeavyHaulTrucker]

Sent: 8/10/2004

Sob said:
"The only difference that I can possibly think of between now and the times it went dead is that I was running off the aux tank when I shut it down when the draw was present and I was on the main tank when I shut it down after Williamsburg and going to the ODW this weekend (it started fine after sitting 3 days there too whereas before, it would have been dead).  "

Sob, unless I miss my guess, I think you may be onto something.  You might want to check to see if the "hot" lead on your tank switch is connected directly to battery + or if it is wired through the ignition switch.  If it is connected directly, then I think you have found your drain... the tank selector solenoid.  I believe that, with your Winnie, the selector valve has to be powered to select the Aux tank; no power to it selects the main tank -- just like mine.

John

[Oz]

Sent: 8/11/2004

The fuel cross-over operates as you said, John.  Dave Bastiani gave me a "show and tell" class on this at the Circle M Jam.  It will be the first thing I check.  You just don't know what kind of creative wiring exists when you get a classic Winnebago until you start to have problems, do you?

[LJ-TJ]

Tail lights Yep! Lauren and I had the same problem. We'd pull in for the night and the next morning the battery would be dead. One night when coming back from Wal-mart Lauren noticed the break lights were still on. I went and pulled the brake pedal and off they went. Started to check each time we stopped and most of the time they were stuck on. Climbed under the drivers front wheel and adjusted the brake light plunger nut and voila. Fixed.

[LJ-TJ]

Just adjust the nut in or out on the brake light plunger. It's in the wheel well on the drivers side.

[Beachcomber]

Hopefully this issue has been resolved, but the comment about the battery charger needle is the clue. It's likely that one or more of the cells in the battery have failed (batteries being of lesser quality generally, due to outsourcing), and will not, as suggested, take a full charge. Enough to start once or twice, but waiting to strand you somewhere later on. I'm a fan of those mobile "booster packs" and am going to check out solar rechargers for next year.