Battery Power - what can I expect??

[Adony]

Please excuse if this is a duplicate... I have a new T25KS travel Trailer that came with 2 new 12v batteries. We last used the TT at the end of July and when put away the batteries were fully charged. Since then I have cycled the slide several times, used a couple of interior lights for brief periods and listened to the Stereo. Today I went to do some work and everything was totally dead. I hooked up my Yahama 2000 generator and then proceeded to see if anything came on that might have been left on accidentally.. Nothing.. The radio was dead so I had to pull the fuse and reinsert it to get the radio going (Problem was it left on?).. All lights, fans, 12 antenna amp, were off. water pump was off.. that only leaves the LP Detector (which is always on) and the thermostat which was in the heat position (although it would never come on as the gas was off).. Is this normal battery decay in 2/3 weeks? If not any ideas what could be causing my either real or perceived problem? Can I remove all the 12 v fuses in the power panel and measure current draw across the respective contacts for each circuit to see if one is drawing more than it should.. they all should be 0 except the stereo and LP detector. Any ideas or suggestions on how to isolate or correct this issue will be immediately investigated as I want to use the trailer next week.

[Herk7769]

If the 2 new batteries were Dekka DC-24's they are rated at 75 amp hours each. Hooked in parallel, that amounts to 150 amp hours of available power.

Amp/Hour rating of battery capacity is calculated by multiplying the current (in amperes) by time (in hours) the current is drawn. For example: A battery which can deliver 4 amperes for 20 hours before being discharged would have a 80 amp-hour battery rating (4 X 20= 80).

The stereo pulls about 2 amps and the various other "always on" stuff pulls about an amp. This would kill both your batteries in about 4 days assuming they were full when you left the rig..

Using the slides most likely left the batteries in a "less than full" state.

As the voltage dropped, the radio (like any computer running on low voltage) most likely locked up and needed a "hard reset."

[LadyWindrider]

When you last used the trailer, did you have shore power or did you dry camp? How do you know the batteries were fully charged when you put it away? How many times have you cycled the slides, "several", is not an answer here. How was the refer left, on gas or auto? The radio will take power when off. Just because there isn't any gas, if it is cold enough for the thermostat to call for heat, it will still try to start the furnace. Still have a lot of details to work out. You're going to need a voltmeter and know how to use it.

[Adony]

When you last used the trailer, did you have shore power or did you dry camp? we were on shore power for 3 days along with driving home connected to the trucks 12v system. How do you know the batteries were fully charged when you put it away? status meter (battery) read full How many times have you cycled the slides, "several", is not an answer here. Slide (1) was cycled 3 times. How was the refer left, on gas or auto? refer was off The radio will take power when off. Understood.. Just because there isn't any gas, if it is cold enough for the thermostat to call for heat, it will still try to start the furnace. This could have been the culprit, Still have a lot of details to work out. You're going to need a voltmeter Have several and know how to use it. 30 years experience with volt meter.. Maybe a battery disconnect switch is the answer...

[LadyWindrider]

Thanks for the answers. the slide is the culprit, maybe. For my refer to be off, it has to be in OFF, not in auto. Also when on shore power, you need to check the battery voltage with a meter and make sure the converter is charging. Might also want to check it with tow vehicle hooked up, to make sure it charges batteries also. Also check the brake "break-away" switch and make sure you didn't accidentally pull it when disconnecting. Lastly, never believe the on board battery "status" meter. Most will show full at 12 volts, when in fact that is about 80 % charge.

[chris t]

I have also seen other parasitic loads (like the gas detector) suck a battery dry when it's partially discharged. The timeframe that you're looking at, that would be an assistant culprit. The disconnect is a good idea, although I just open the battery box and disconnect the + cable. I'm cheap.
Ct..

[Adony]

Thanks for the answers. the slide is the culprit, maybe. For my refer to be off, it has to be in OFF, not in auto. I believe it was in the off position.. Also when on shore power, you need to check the battery voltage with a meter will do in morning and make sure the converter is charging the converter must be charging as after running the unit on my generator for several hours and then disconnecting it, my batteries now have power for the lights / limited slide action.. more charging will be done tomorrow... . Might also want to check it with tow vehicle hooked up, to make sure it charges batteries also. 12 vdc available at proper pin on truck connector.. Also check the brake "break-away" switch and make sure you didn't accidentally pull it when disconnecting MUST CHECK THIS AS IT IS A REAL POSSIBILITY. Lastly, never believe the on board battery "status" meter. Most will show full at 12 volts, when in fact that is about 80 % charge.. Thanks for the help... will know more tomorrow after checking above items...

[Herk7769]

Originally Posted by chris t

I have also seen other parasitic loads (like the gas detector) suck a battery dry when it's partially discharged. The timeframe that you're looking at, that would be an assistant culprit. The disconnect is a good idea, although I just open the battery box and disconnect the + cable. I'm cheap.
Ct..

Disconnecting the ground wire is just as effective and safer in my opinion.

Adony, I believe everything is working correctly with your system. The meter on the the KIB Micro Monitor will read full as long as the voltage is about 13 volts or more. I used to use it as a "Charging/topped off" indicator.

The remote display on the TM-2025 battery monitor is now my primary indicator. When my battery disconnect switch is in the OFF position the TM-2025 still reads battery voltage and you can see it drop over time simply from internal reststance in the battery itself.

[KyDan]

Originally Posted by Adony

Maybe a battery disconnect switch is the answer...

BINGO! Your power center charger itself will gradually
suck down your batteries. Also the LP detector as you
said. I have added a battery disconnect switch to each
of my trailers. This has been discussed here many times.
It's a fairly easy job. I put mine in the toe kick area
below my kitchen cabinet right next to the power center.
It's a 1 or 2 beer job easy!

You can pull fuses one at a time and use a multi meter
set to read Amps. The meter should be capable of reading
a couple amps without frying the
meter! When you place the meter probes across the
fuse terminals (with the fuse removed) you will
see the current going to that device. I found current
going to my on board battery charger (power center)
as well as my LP detector.

Several of us here have used battery switches similar to
this one--
Amazon.com: 9001e e-Series Battery Switch Selector: Sports & Outdoors

I used the same brand but mine is just off/on.
(I didn't see the need for the 1-2-both battery modes.)
Amazon.com: 9003e e-Series Battery Switch Single Circuit ON/OFF: Sports &…

Also when my trailer is at home I have it connected
to a battery tender Jr. I still shut off the battery disconnect
every time it's not in use but the battery tender stays
connected until we hitch up.

RANT MODE ON-- BATTERY DISCONNECT SWITCHES
SHOULD BE STANDARD EQUIPMENT ON ALL RVs!!!
Rant off........

[Herk7769]

The two battery one.

[Adony]

This morning after charging the batteries for about 2 hours yesterday when connected to the generator (power panel charging batteries), the lights were bright and nothing was dead.. yet! I checked the new Exide batteries and they were full of acid and read 11.89 volts (realizing they were not fully charged).. Once connected to shore power, I can assume the power panel was charging them correctly as they each read 13.58 vdc. I will let them charge for a few days. I found that the brakeaway brake switch had NOT been pulled.. I must then believe that I must have left either the refrigerator switch in another position than OFF, the furnace switch in heat or the radio/lp just drained the batteries. Next question.. I want to install a battery disconnect switch in the fall and locate it some dry, easily accessable location rather than near the batteries on the A-Frame. BUT THAT IS THIS FALL.. in the near term, has anybody had any experience or comments if I use something like depicted in the picture below that is available locally?

[Herk7769]

Sounds like you dodged a bullet!

As to the switch. If you leave the batteries in your camper for the winter; you MUST not use the disconnect and DO keep the unit plugged into shore power (15 amp is fine). That will trickle charge the batteries and keep them warm so they don't freeze.

If you can not (or don't want to) use shore power you "MUST" remove them to a warm place. The batteries will discharge (due to internal resistance) even disconnected and then freeze if you don't.

[bikendan]

Originally Posted by Adony

in the near term, has anybody had any experience or comments if I use something like depicted in the picture below that is available locally?

i use a similar Automotive one from Walmart. the knob is green and i had to add an adapter to get the Walmart one to fit on a deep cycle battery. cost about $4.
i've used it for 3 years before a piece broke off from the RV tech working on it. just put a new one on and it works fine. i have to lift the box lid to disconnect but it's works and is cheap.

[Big bird]

I just got home from a visit to the dealer and a check up of the electrical system. Both new batteries dead. Did the slides a few times just like you and the LP sensor is connected directly to the batteries. It is apparently the law. The battery shut off key does not disconnect the LP senor.

I now know how to pull the fuse and avoid battery drain. I will no longer open slides with battery power unless circumstances permit. Apparently, when the batteries discharge too much the LP sensor is enough to fully discharge the batteries.

I know I have a lot to learn, but this is getting crazy.


Big Bird

[Herk7769]

Originally Posted by Big bird

I know I have a lot to learn, but this is getting crazy. Big Bird

Fire Hose anyone?

[Herk7769]

The manual had the voltages that turn on the appropriate lights and what they mean.

Micro Monitor Panel
BATTERY READ OUTS

CHARGE 12.70 TO 12.85
GOOD 12.10 TO 12.15
FAIR 11.60 TO 11.65
LOW 6.00 TO ALL
VALUES IN D.C. VOLTS ± 5%

http://www.kibenterprises.com/troubleshoot/m_panel.pdf

[acadianbob]

Things don't have to be an ordeal. Like KyDan, I just disconnect the battery and keep a battery minder on it. ALWAYS fully charged when we are ready to go.