Battery Drain

Kev · 02-12-2018, 02:26 AM

I went to pick up my RV Today after two weeks in storage and the coach batteries are dead. I had it the switch in the store position. I’m sure this has been discussed before but I am trying to figure out what the parasitic draw is. My Vegas never had this problem while in storage.

Thanks

Mr Sunshine · 02-13-2018, 12:14 AM

Grrrrrrrr! Can't diagnose your problem, but would suggest you install a cut off switch on your coach batteries. You won't know the culprit, but that might solve your problem and save you from a lot of trouble.

Hikes in Rain · 02-13-2018, 12:46 AM

This, absolutely. After burning up a set of coach batteries by SOMETHING drawing them down, I installed a disconnect switch. Now, every time I open the switch, I hear a relay disconnect! Something was drawing a lot of power.

Kev · 02-13-2018, 01:57 AM

Thanks for the replies I appreciate it. That was the way I was leaning. Now for a stupid question do I need two disconnect switches since I have two batteries? Is there one you recommend?

Thanks

Pete'sMH · 02-13-2018, 02:13 AM

I put a knife disconnect switch on the negative battery post and like Hikes in Rain I use it every time I store the coach. It’s a 100% mechanical disconnect. Simple and bullet proof. You only need one even if you have two coach batteries. Two if you also want to disconnect your chassis battery. I don’t.

Mr Sunshine · 02-13-2018, 02:15 AM

Hey, no stupid questions! You only need one disconnect. There's only one positive connection to the coach from the two batteries and only one negative from the two batteries to the ground. The disconnect goes on the negative where it goes to ground. Here's a vid:

https://www.youtube.com/watch?v=YJxq7SRPOIU

Hikes in Rain · 02-13-2018, 02:35 AM

Mine's not wired that way. I put my switch on what looked like the grounding cable (negative to the chassis). Still had power. Hmm.....

Just for giggles, moved it to the other battery negative post. Still had power. Hmm...again.

Got another switch, one on each battery. Opened both, heard the relay click, no power.

My rig has has positive cables coming off each battery, and negatives off the inboard one, heading off into the coach. I'm not smart enough to trace them all down, but it seems each battery is wired to power different "stuff", rather than the two batteries wired in parallel. Came from the dealer this way.

Kev · 02-13-2018, 03:25 AM

Quote:

Originally Posted by Pete'sMH

I put a knife disconnect switch on the negative battery post and like Hikes in Rain I use it every time I store the coach. It’s a 100% mechanical disconnect. Simple and bullet proof. You only need one even if you have two coach batteries. Two if you also want to disconnect your chassis battery. I don’t.

Like you Pete the chassis battery is no problem. It’s the coach batteries that seem to go dead.

kkbaker · 02-14-2018, 05:11 AM

Vegas radio/camera system was my drainer if I had CD loaded and somehow even though the unit seemed turned off before storage, somehow radio pulling power.
While unit new on dealers lot the battery was dead and when charged immediately the radio blared, so it was left on inadvertantly. Just a clue from my experience.

wiscpicker · 02-14-2018, 10:07 PM

Quote:

Originally Posted by Kev

I went to pick up my RV Today after two weeks in storage and the coach batteries are dead. I had it the switch in the store position. I’m sure this has been discussed before but I am trying to figure out what the parasitic draw is. My Vegas never had this problem while in storage.

Thanks

This seems to be a flaw in design with Thor. The main engine battery will drain completely as well. There is a safety switch that is to stop this from happening which seems to be a weak part in engineering. I had to have this relay replaced. The problem I have found is very few repair places has anyone who has any knowledge to diagnose problems. I have found an experienced mechanic in Florida who has performed numerous repairs on the Thor units.

Johnarm1 · 03-04-2018, 03:32 AM

I have experienced severe battery drain twice now in the 2 weeks I have had the coach. In both cases the Use/Store switch was in the Use position. With everything turned off the battery would drain in two days. If one is dry camping this could be a problem. I installed a current monitor and pulled fuses to find the drain. The propane/smoke detector pulls .1 amps. The audio/video circuit pulls .5 amps. Does anyone know what could be drawing power. The radio is OFF. Thanks in advance.

Miramar Owner · 03-04-2018, 02:37 PM

Does your coach have auto gen start? If so make sure it is off. The generator will not charge your batteries when in store mode but the AGS will still try to operate. I learned from experience...seems to be my best teacher lately.

Bob Denman · 03-04-2018, 05:11 PM

Quote:

Originally Posted by Hikes in Rain

Mine's not wired that way. I put my switch on what looked like the grounding cable (negative to the chassis). Still had power. Hmm.....

Just for giggles, moved it to the other battery negative post. Still had power. Hmm...again.

Got another switch, one on each battery. Opened both, heard the relay click, no power.

My rig has has positive cables coming off each battery, and negatives off the inboard one, heading off into the coach. I'm not smart enough to trace them all down, but it seems each battery is wired to power different "stuff", rather than the two batteries wired in parallel. Came from the dealer this way.

I had the exact same thing going on with mine...

I'm letting the dealership figure out where to put the bayonet switch.

mbs.shaffer@gmail.com · 03-09-2018, 01:48 AM

Instead of installing a cutoff switch for each battery, wouldn't it be sufficient to simply push the trip button / circuit breaker on each battery (which makes the little flag pop out)? That should cut the power without having to install another switch?

Am I missing something?

By the way, my rig was in storage for 1 month (no power) and my house batteries are completely dead

Squid · 10-14-2018, 06:56 PM

I am having a mysterious draw on my coach batteries....I can put my volt meter on the battery and watch it go from 12.30 to 11.30 in 5 minutes or less. I had put two new agm optima sealed batteries in, two years ago. I wonder if they have gone bad? Camping World installed a new converter last July. Wonder if that has something to do with it?
As long as I am on shore powe everything find.. but forget boondocking till I get this figured out.
Thoughts?

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