12V use warning

[Azlugz]

This is mostly for the 5th wheel but also for the mods I am planning for my Jeep and for my Jumping Jack.......

Several times now we have put the 5th wheel back in storage and come back later to find that we had left something turned on...light, water pump..... and now we have dead batteries.

I use a single 15w solar panel to keep the batts topped but if you leave a light on, it can not keep up.

What I am looking for is a way to build something that will tell me if there is power draw when in storage. I light that will come on or a meter, something graphical.

I can't just shut off the battery circuit because the solar is hooked in by the fridge and because there are clocks that use minute amounts of current to keep time, but there should be nothing drawing any significant current.

I have had a couple ideas but not ones that I like, so I am looking for other thots and ideas. Any help is appreciated!!!

 

[FusoFG]

a checklist of things to turn off when you leave the camper.

hang it by the door.

 

[dms1]

I disconnect the Negative battery wire from my House Batteries when it is in storage, it only uses a wing nut for the connection so it is real quick to disconnect and reconnect. You could also put in a heavy duty battery switch inline.

 

[SunTzuNephew]

An ammeter will show if there is any load on.

Or pull the fuses for everything. Or install a master battery off switch.

 

[Ursidae69]

Xantrex makes really high-end products. Try one of their battery monitors, like this one: http://www.xantrex.com/web/id/273/p/1/pt/7/product.asp

 

[Herbie]

An ammeter will show if there is any load on.

This is what the OP really needs. What you want is a "push to test" ammeter (preferably analog) that will sit right on the house battery positive line.

First, set a baseline by double and triple checking that EVERYTHING is off as it should be (except for your dark-current consumers like clocks, etc.), then test the current load a couple of times and get a good average number (will be small, probably in the milliamperes range). Since you have a solar input, you may need to get baselines for light/dark conditions or have some other way to eliminate the variable current input.

Then, when storing your 5th wheel, just check the ammeter before you leave. Any reading much higher than the baseline value will indicate that you still have a current drain in the line, due to a lamp, appliance, etc.
Growing electrical problems such as corroded wiring, etc. can also be diagnosed with an ammeter if you notice that the current consumption for a given set of uses/devices starts to rise over time.

 

[dms1]

I think you will find that even if you turn everything off, there is still going to be a small load on your batteries that will drain them. On my motorhome there are gas monitors, Smoke detectors, exhaust fans (that turn on and off automatically) and even battery\water\sewer gauges, that stay on all the time unless you remove fuses or turn off breakers.

On my motor home it is easier to access the batteries that the circuit breaker, so that is why I disconnect the ground wire.

 

[Azlugz]

I think you will find that even if you turn everything off, there is still going to be a small load on your batteries that will drain them. On my motorhome there are gas monitors, Smoke detectors, exhaust fans (that turn on and off automatically) and even battery\water\sewer gauges, that stay on all the time unless you remove fuses or turn off breakers.

On my motor home it is easier to access the batteries that the circuit breaker, so that is why I disconnect the ground wire.

yes and as I stated there are also clocks. But since I have the clocks and the solar, I do not want to disconnect the batteries.

 

[Herbie]

The OP seems to be aware of (and able to tolerate) a certain amount of dark current. The 15w solar panel in use should be more than adequate to keep things happy under those conditions. Anything less than a constant 500mA or so should be OK, and 500mA is a HUGE amount of current for running things like clocks, detectors, etc.

 

[sargeek]

The single largest consumer on my trailer is the propane detector. It will kill the battery pretty fast. The other problem is that the detector is always hot, and cannot be turned off, unless I disconnect the battery.

You will have to figure out how to identify and turn off the parasitic drains, or install a larger solar pannel to compensate for the drains.

 

[grntrdtaco]

you could get a 2nd fuse box for all other accessories and put a breaker on it.

when you put it away flip the breaker and every accessory attached to the aux fuse box gets disconnected.

t

 

[Azlugz]

its a new 38' bunkhouse!!!!!

Don't think I can redo the wiring in it!!

 

[Herbie]

The single largest consumer on my trailer is the propane detector. It will kill the battery pretty fast. The other problem is that the detector is always hot, and cannot be turned off, unless I disconnect the battery.

You will have to figure out how to identify and turn off the parasitic drains, or install a larger solar pannel to compensate for the drains.

From the original post, the problem he is trying to solve is identifying when LARGE consumers like lamps or water pumps have been left switched on. A 15W panel should be able to keep up with normal parasitic drains unless they are very large. Even assuming efficiency losses, that panel should be able to put 1A back into the battery for at least 8 hours or so per day, barring serious shading or weather issues. 8AH split over that same 24 hour day means anything less than a 333mA constant draw is "covered" by the panel. A basic test will confirm if his dark current is less than this.

 

[Dendy Jarrett]

I use a battery bug (argus) to monitor the battery. It has an audible alarm if it gets below a certain percentage of charge.
I'll post some pics later.

D

 

[KG6BWS]

Do you have the option of using 110v shore power when storing it?? Having it plugged in would be a better option than a small solar panel.

I agree though with the checklist and the ammeter. Those would be your two best options for detecting any kind of larger drains.