Battery drain issues

[KayLarGo]

We have a 2005 Newmar Mountain Aire on 8.1 workhorse chassis. We have been experiencing battery loss on the chassis battery taking it to around 8.5 volts in about 1.5 to 2 weeks. This week the coach battery was also down to 8.5 even with the Shore Power ( SP) in. The Chassis battery is New (an Optima) and the coach batteries are about 2 years old and very little use but on (SP). Water is at level and stays there.

My neighbor and I ( both retired engineers) decided to go after this today. With my new Craftsman Professional True RMS AC/DC Clamp Ammeter, we started taking measurements. When checking the positive wire for amps on the chassis battery, we checked it plugged in to shore power ( SP) and unplugged. In store ( unplugged) there was no draw ( .o1-.02), plugged in we had .5 amp draw. We were also monitoring the A/C voltage to the cabin. At 120v we had the .5a draw and when we turned on heater etc to load the volts to 108v the battery draw went to 2.amps. We tryed it several times and never were able to get it to go to 2.0 a again and stayed at .5a .

My question is 1. why is there a .5 amp draw on the chassis battery when on (SP) and 0 when not on (SP)?
2. could the low 108 VAC to the converter/charger cause a drain on the coach battery and chassis battery?

We did go though the exercise of pulling all fuses and watching draw and concluded nothing was on and did that in store mode.
As our desire is to plug in to (SP) and run refig etc this seems to be a problem.

Thanks in advance as I know there is some real talent here.

[KayLarGo]

We have a 2005 Newmar Mountain Aire on 8.1 workhorse chassis. We have been experiencing battery loss on the chassis battery taking it to around 8.5 volts in about 1.5 to 2 weeks. This week the coach battery was also down to 8.5 even with the Shore Power ( SP) in. The Chassis battery is New (an Optima) and the coach batteries are about 2 years old and very little use but on (SP). Water is at level and stays there.

My neighbor and I ( both retired engineers) decided to go after this today. With my new Craftsman Professional True RMS AC/DC Clamp Ammeter, we started taking measurements. When checking the positive wire for amps on the chassis battery, we checked it plugged in to shore power ( SP) and unplugged. In store ( unplugged) there was no draw ( .o1-.02), plugged in we had .5 amp draw. We were also monitoring the A/C voltage to the cabin. At 120v we had the .5a draw and when we turned on heater etc to load the volts to 108v the battery draw went to 2.amps. We tryed it several times and never were able to get it to go to 2.0 a again and stayed at .5a .

My question is 1. why is there a .5 amp draw on the chassis battery when on (SP) and 0 when not on (SP)?
2. could the low 108 VAC to the converter/charger cause a drain on the coach battery and chassis battery?

We did go though the exercise of pulling all fuses and watching draw and concluded nothing was on and did that in store mode.
As our desire is to plug in to (SP) and run refig etc this seems to be a problem.

Thanks in advance as I know there is some real talent here.

["007"]

I'll take a try your radio is off your house batteries but your LP detector is off your coach batt, you have a switch to disconnect the LP detect above entrance door on my coach, which reminds me I did not operate to shut off because when I went to start engine the other day I had a low battery.
I have always left my coach plugged in during winter months but was going to leave unplug this winter.
The small solar panel should keep your chassis battery up like mine has the last few winters so that LP DETECT must draw enough to bring down chassis battery if that switch is not thrown.

[KayLarGo]

What I can't figure out is why there is no drain when of shore power? I thought the LP detect was always on no matter if on or off shore power. Our RV doesn't have a LP detect shut of unless you unplug it. We are in a covered parking stall so the solar doesn't work. Hummmm

[RVDude]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">1. why is there a .5 amp draw on the chassis battery when on (SP) and 0 when not on (SP)? </div></BLOCKQUOTE>
I take it you mean there is a 0.5amp 12VDC draw FROM the battery while on SP?
This may be a stupid question but are you sure you are reading a "draw" and not a "charge"? It would seem logical that while on SP you are actually reading a 0.5amp 12VDC float/maintenance charge?

An inverter without any 120VAC load will draw some 12VDC just to power the inverter circuits, but 0.5amp 12VDC seems high for the base inverter load. My LP detector draws about 0.25amp at 12VDC.

Isolating pahantom/parasitic loads is a nightmare. You might try completely removing the battery cables and let the battery just sit to see if it is discharging all by itself.

[Jack Foster]

The propane detector switch should be over the door with all the other switches / tank levels etc. I think it's just labeled propane.

Jack

[Ecker]

The battereies are dead at 11.7 - 11.89 volts and in that condition they can not be properly tested or evaluated. You need to get them back up to a fully charged state which may require days with a small charger.

[KayLarGo]

RV DUDE --I sure this is a draw. We also turned on things and saw it increas correctly. Our chassis doesn't get a charge from the IOTA DLS 75 converter and is isolated. The only time the house battery and chassis are connected is when the engine is running and when the boost switch is on. I guess I'm a little confused. We could clearly see a draw of .5 amp when plugged into the shoure and saw it go away when in store and not plugged in

[KayLarGo]

ECKRE -- THe batteries were down two days ago and all systems were charged for todays test and were stable at 12.8 vdc

["007"]

That LP detect is off the chassis batt and if you don't throw switch its going to drain your batt and parked under cover, chassis batt will not charge off panel, you need a Trik-L-Start from RV-Upgrades to keep up your chassis batt.

[rebelsbeach]

Speaking of rvupgrades, ya'll need to check out their EXPANDED rv accessory online catalog...

They've recently added hundreds of new items and they're an iRV2 sponsor as well!

[KayLarGo]

007 --- I think you are dead on. I have been on a discussion on another forum about this and this is our conclusion. I wasn't really educated about the LP detect and thanks for confirming that for me. Under cover, being in Seattle isn't good for the solar charge and 18 degree weather last week. I was on shore power and a heater on so the ac probably dropped under 108 and the converter stopped working or went nuts discharging the coach bat and the LP etc discharged the chassis bat. Do you hook the trickle charger to the coach a/c or just drop a cord and hook it up externally? We just purchased this in May and am just getting my knowledge base together. ---- Also I have a LP on/off switch on the panel above the door. I thought that turned the LP on or off from the tank to the appliances. Is that the LP detect sensor switch? Sorry for the ingnorance. Thanks everone for your information. This is a really great resource !!!

["007"]

Yes the switch is for killing the LP detect only. The trik-l-start hooks up to your chassis batt and plugs into a working ac outlet externally. If you go to RV-upgrades on this site I think it will explain how it works.

[KayLarGo]

oo7- Thanks for the info---I drove to my dealer here in Seattle today and talked to the tech and found that the difference between "store" and being plugged into shore power is on Shore Power the radio, clock and rear view mirrow with temp etc gets turned on accounting for the draw. I also had the LP sw on for more chassis battery draw. I went to Camping world and purchased the BatteryMINDer 12 Volt - 1.33 AmpCharger-Maintainer-Conditioner (Desulphator) up to 5 Batteries 12117 and put a 12V male appliance adapter on it and pluged it into the dash. I put the shore power cord in. All batteries are ar 13.2-3 and looking great. What a difference a ittle education does. I did look in the Newmar manual and CD and none of this information exists there or about the LP switch. I had to go to "My Computer" on the CD to see the diagram files there. Boy-- every diagram is there. I wish this information was easier to get from Newmar instead of a crisis. Thanks for the help......