Phantom Load/Battery Issues

[danesk]

Since we first purchased our 2000 Concourse, I've noticed a coach battery drain during brief storage. I've disconnected CO detector, fire alarm is separate battery, fridge is off. I keep the coach batteries charged with a small smart battery charger (4 stage), so it takes quite a while to get the batteries up if they haven't been charged for awhile. They are 2 100 AH Windy Nation deep cycle, new just 8 months ago. Unfortunately, after the batteries are fully charged, according to the battery charger, the voltage drops to 12.5 - I believe that should be closer to 12.8 to indicate a full charge. Could I have a defective battery?

Previous owners added a monitor (not tv) and a Sony radio in the cab, so some re-wiring was done.

I made some current tests this AM with the clamp-on ammeter and will add an illustration of the results - I am wondering if these current readings are normal. If .5 amp is drawn continuously, that adds up substantially.

We will be adding two 100 watt solar panels and new MPPT controller soon, so I want to work out any phantom load or battery problems before doing so.

Thanks in advance for any and all advice!

[68camaro]

I never found mine so installed cut-off switch on engine and coach batteries. It has made a big difference when storing for any length of time.

[Blue~Go]

I don't have any measurable parasitic loads on the house when parked. I live by solar so every amp counts and a .5 amp load would be a headache (12ah per day). So it is possible if it's something you care about (I do).

My start battery is fine for a couple months but there is some very small (Ford) load. I don't typically park for more than two weeks so it's ok.

Some notes:

1) Stock "coach" stereo gets power for the preset holding wire from the start battery. That could drain it more quickly than I would like, so I re-wired it to run completely off the house battery. (Thanks to original effort by BobW.) If I turn my coach batteries off I would lose my presets, but one thing is I rarely do that, and the other is that if I'm traveling presets don't stay valid anyway.

2) Chinook left quite a few loads "hot" even when the switch is in the "store" (off) position. Also, because they used one wire for loads and charging, you need to leave that switch on anyway if you want to charge. So figuring out those loads could give you something to test (they have been mentioned here before, but I don't remember them all*).

*A few possibilities off the top of my head:

1) Coach stereo might have some permanent draw (not sure but worth checking)
2) Detectors, as you mentioned.
3) Electric step I believe runs from start battery, but not positive (I have manual step).
4) Propane (absorption) refrigerator uses some small amount of power to run circuit board.
5) TV or VCP might have some "quick start" feature that means some power is always on?

Maybe others can help us remember some of the other culprits.

Another idea is you can pull your brown box fuses one by one (try with switch both on and in "store" and see if your load goes away).

Also, while testing you may want to pull the fuse from the solar panel (or cover it with a blanket or do it at night). Typically it's a 12 gauge black/red wire pair that goes right to the battery and IIRC has a glass inline fuse? Otherwise incoming solar might mask things.

Also be aware that if you have the Sure Power 1315 combiner it is bi-directional, so if charging power is going to either start or house side, it can open to "share" the charging with the other bank.

[chin_k]

Besides the suggestion of a cutoff switch (which can be ignoring if you have the solar working... it makes the battery isolation solenoid clicks constantly!), I think it is worth while to figure out why it is draining 0.5A when "off." If it is my rig, I will start disconnecting/reconnecting thing while the ammeter is on there to see which one(s) is the culprit that keep draining the batteries down. It is more an exercise in bookkeeping, and not difficult to figure out once you have the right tool (i.e., the ammeter).

[Blue~Go]

In case it wasn't clear in my rambling screed above, I agree with what chin_k said in one succinct paragraph

[SMan]

The batwing antenna being left on has been an issue for me. I put a post-it on the dash.

[chin_k]

I think Blue's more detailed comments are more useful, however. I am lazy, and want people to come back with more question if they need more detail. I paid pretty well for give out details instructions, and I am certainly not doing it for free here!

One thing is that Trail Wagons changes how they do the wiring, so a parasitic issue for one rig can be a non-issue for others. For example, none of my detectors (CO/propane/smoke) will work unless the power is on. I can't stay/sleep in the rig if the switch is on "STORE." YMMV.

[danesk]

Thanks to all for the awesome advice!

I will start by removing fuses one by one to try to determine where that .5 amp is going...

Only if worse comes to worse will I install a disconnect switch on the coach batteries. I do have one for the start battery, which gives me a peace of mind when we are out in the middle of nowhere for a few days.

Will post back here if/when this issue is resolved.

Dan

[danesk]

Greetings,

The mystery continues...I measured 1 amp at the negative cable first thing this morning and then systematically removed each 12V fuse with both the Coach Battery switch on and off - no difference in any circuit with switch on or off. I did find that the TV circuit was drawing .5 amp and I removed that fuse - the TV had been replaced with just a monitor connected to the original Kenwood VCP.

I also tested with the start battery disconnected - no change.

But there is still .5 amp being drawn even after removing each fuse. Where in the world could that load be if I have removed each circuit's fuse?

Thanks again for any and all advice!

Dan

[caconcourse]

Greetings,

The mystery continues...I measured 1 amp at the negative cable first thing this morning and then systematically removed each 12V fuse with both the Coach Battery switch on and off - no difference in any circuit with switch on or off. I did find that the TV circuit was drawing .5 amp and I removed that fuse - the TV had been replaced with just a monitor connected to the original Kenwood VCP.

I also tested with the start battery disconnected - no change.

But there is still .5 amp being drawn even after removing each fuse. Where in the world could that load be if I have removed each circuit's fuse?

Thanks again for any and all advice!

Dan

Just about all that's left is the LVD and possibly the solar controller, especially if you still have the original. There are two wires from the battery to the LVD, one smaller sense wire and one large distribution/charge cable. You could measure each of the two independently with the meter, and you could temporarily try disconnecting them one at a time and see if the current draw goes away. You should also remove the in-line solar fuse near the battery while you are measuring to get the solar out of the picture.

There might also be a partial short somewhere. There are a couple of circuit breakers between the battery and the LVD that have been know to corrode over time. You could also try temporarily removing the rear connector from the Kenwood unit to eliminate any connection between the coach and truck power systems that may pass through the unit.