Battery Charge Longevity

Sopper · 04-20-2014, 06:22 PM

As many of you know (as seen on recent postings) I went through the process of de-winterizing my TM and hooking batteries up appropriately. Last Saturday I purchased a new, 12V, deep cycle battery which replaced my dual 6V batteries. All has been good until today.

I added a hitch-mounted level and wanted to adjust the trailer slightly. Tried the powered tongue jack and no response. Tried the front light on the TM and it was very dim. A garage stored TM should not be draining a 12V battery in a week should it? The TM is completely closed and no external lights are on.

Help! What is going on? Is this drain to be expected? Should I continually keep by TM connected to shore power to ensure my batter stays charged?

Thanks, as always, in advance for your assistance!

Padgett · 04-20-2014, 06:33 PM

Need to put an ammeter on the battery and measure the idle current, the converter is going to take some and the refrigerator might be on DC. If none or little (under 50 ma) then need to do a load check on the battery, it may have a dead cell.

Bottom line need to do some instrumentation and triage, are too many possibilities now.

tentcamper · 04-20-2014, 08:31 PM

Something drained the battery. It should not have draine that fast. But maybe the battery was not fully charged when you got it.

I have a battery turn off switch on the pos post and the TM is wired to it, I have my jack wire to the stud on the battery so it always hot.

Is it possibly you left something on in the camper? I know my unit the radio amp is always, not sue about the LP detector?

Sopper · 04-20-2014, 08:31 PM

Battery is brand new. Fridge is in the 'O' position (which I assume is off). How can I check the load on the battery? I have a multimeter. Should I pull the battery connections off and test the wires?

Padgett · 04-20-2014, 09:00 PM

Most DVMs (I have a gaggle of DVMs from HF, they keep being a freebie) have a 10A scale. Put in series with the battery and see what the quiet (everything turned off you can) drain is. Under 50 ma is fine, 200ma will drain a normal battery in less than a week.

I put a little 50ma float charger on everything I am not driving daily.

Do see a green light on the detector and a red light in the radio (soon to be replaced with something having Bluetooth and an aux jack) when the coach is dark. Disconnect on the battery is a real good idea if you do not care about the radio presets.

tentcamper · 04-21-2014, 08:37 AM

If you can get an amp meter, and you have to much draw. I would start pulling fuses to determine where you are drawing the amps.

On my unit, I notice that the amp for the TV antenna has a small switch next to the cable plug. There is a dim led there if on. If you have a radio, I would make sure it off. I read but not sure, that even if turned off a auto radio radio. They still will draw amps unless there is a separate on/off switch that is switched to the ignition wire on the radio?

Anyone know how to turn off the amp for the radio antenna. I know at night if power is going to the TM, I have a very dim LED up by the radio antenna?

LoveToCamp · 04-21-2014, 10:15 AM

You definitely have a problem, especially if your solar is constantly connected. The solar should be re-charging any parasitic draw you have, and keeping your battery charged.

I second the motion for a battery isolation (cut-off) switch. I put one on my old TM, mounted on the outside of the battery box (my battery was on the tongue). My new one is on the end of the dinette, so I can retract the slide, and cut the power before closing the TM (battery is under dinette bench, so is not accessible from outside).

Good luck finding the drain! It should not be draining in a week.

**Bill** · 04-21-2014, 12:03 PM

As Padgett suggested, it is normal (though unwelcome) for the parasitic loads in a camper to drain the battery in about a week if you simply turn everything off and close the camper. Do a Search of the Electrical Forum for "parasitic" or "phantom" for more details.

You need to either
o disconnect the battery (you can add a switch, or simply pull the main fuse located at tthe + post of the battery)
o connect an external charger - a small one will do nicely, and if it is handier you can connect it at the Bargman connector rather than the battery), or
o provide shore power to the camper while in storage so that the TM's converter can keep the battery up.

The first option is easiest, and guarantees no battery drain. The third option is good for short-term storage, meaning a week or so, but NOT good for long-term storage, meaning a month or so. Most TM converters will eventually overcharge the battery. And of course, solar will do you no good if the TM is in the garage. Incidentally, never use a garage-style charger.

Bill

Sopper · 04-21-2014, 02:35 PM

Bill:
I have several trickle chargers (the ones which maintain a battery at a given voltage and shutoff once past that voltage) that I used on the batteries in the winter. Are there kits or instructional diagrams to wire these into the bargman?

How long can I rely on plugging into shore power to maintain the battery without damage?

You had mentioned using an in-line shutoff switch. Do you have one available online that you would recommend?

Thanks as always!

-Jason

**Bill** · 04-21-2014, 05:44 PM

Jason -

Take a look at this picture in my Tech Album
http://www.trailmanorowners.com/foru...&pictureid=442

The upper diagram shows the trailer half of the Bargman. You would hook the charger to the pins labelled "12 V" and "Ground".

A good example of a Battery Cutoff Switch is Item #66789 at Harbor Freight. You can get a similar switch for a lot more money at Camping World (Catalog Item # 69568) or West Marine.

As for how long you can leave shore power connected, letting the TM's converter keep your battery charged, it depends on which converter is installed in your TM. But as I said, I wouldn't do it for more than a couple weeks to a month. And when you roll the TM out again, be sure to check the battery water level.

Bill