The title says it all.... I returned from a weekend camping trip about 5 weeks ago. I was fully charged when I pulled into my driveway, unhitched, and put everything away.Today, I went into the trailer to get ready for our next weekend trip, and had no power. The battery monitor in the power panel showed 1 light (out of four). But none of the lights would turn on (although all the indicators on my panel for water, black/gray tank, etc, all work.)This is the original OEM battery. We purchased our HTT new in Oct. I know there are some parasite drains, even when everything is turned off and I'm planning to install a battery disconnect.DW and I are complete newbies and have no point of reference.... Is it normal for a battery to last only 5 weeks when parked?

Never leave my rig for more than a day or so unless I disconnect the battery.

Sounds about right. There are parasitic draws all over the RV. Install a battery disconnect or plug it in are the only choices.

ricks99 wrote:Is it normal for a battery to last only 5 weeks when parked?No, actually much less than 5 weeks. Probably 100 to 500 milliamps or 5 to 15 amp/hrs drain per day. Battery holds maybe 90 of which you should only use 50 percent or 45. So you need to plug in every 3 to 9 days. Or disconnect a cable and you are good for 3 to 6 months. Even disconnected you need to start tip-top 100 percent charged.The 12 Volt Side of Life

I completely disconnect my fully charged battery bank when parked here over the winter months... It starts out reading around 12.6-7VDC and usually only drops down to around 12.4-5VDC over NOV DEC and JAN...During the winter months I can read my batteries with only my Battery monitor meter connected and I usually check on it ever two or three weeks...Sometimes when it gets down to 12.5VDC I will hookup my trickle charge for a day or two... This next winter season I will have my 10WATT small solar panel hooked up all the time giving the batteries a slow continuous trickle charge.If you let them set you have to pull one of the battery terminals otherwise the parasitic drains will run them down in just a week.. Its best to install a disconnect switch as removing and replacing the battery terminal may or may not keep you with a good solid connection depending how tightly you install the terminal each time...Hopefully your batteries are not damaged. Once they go below 12.0VDC it is like driving a nail in their coffin... Do a slow long charge on them using a smart mode charging mode charger. Do it two or threes time in a roll...Got to take care of the batteries as they are your lifeline for trailers.AT least once a month when sitting here between trips I do a walk around and read the sitting battery voltage. I like to always read at least 12.5VDC or more. Then I switch in the batteries to the trailer and hook up to my garage receptacle which turns on the converter/charger unit and then I look at the battery terminals DC VOLTAGE again and I want to see it jump up to the 13.6VDC or higher depending what smart mode the charger jumps up to. If I don't see the DC VOLTAGE jump up then that tells me my Battery charging system is not working... Roy Ken

How long should my battery last (when not in use)?

25 Replies

mike-s
Explorer II
May 09, 2017
If it's stored outside, for <$100 you can get a small solar panel and controller, and that will keep the battery charged to a reasonable level (better than most 12V converters will when plugged in).

20-30W panel ~$50, suitable controller ~$20, plus wire and a small bit of effort. That's enough to charge a common small RV battery between weekends.

Or just get a very small battery maintainer panel (5 W or less, bigger needs a controller to prevent overcharging). <$20. That will keep a battery charged, but won't do much to recharge a drained one.
pnichols
Explorer II
May 09, 2017
We've went on three RV trips of 8-10 weeks each. Our sedan (wet cell battery - not AGM) sat in the driveway and started just fine after all three trips.

Why can't RV wet cell batteries do the same .... assuming you switch OFF the RV's battery connection to the RV's 12 volt system? We have a switch right by the battery compartment to do this.
brulaz
Explorer
May 09, 2017
MrWizard wrote:

...
I'm not sure you could leave your tow vehicle sitting for five weeks and still have a good battery, maybe.. maybe not
...

After 7 weeks both batteries were completely dead and and had to be replaced in my 2016 RAM 2500 diesel.

So I read the manual, and it says to disconnect the neg battery leads if storing for over 3 weeks!

Think the truck needs a battery disconnect too.
NinerBikes
Explorer
May 09, 2017
ricks99 wrote:
Well.... installed a battery disconnect switch over the weekend. I recharged the battery then turned the switch OFF. Battery should be good to to go until our next trip (Memorial Day weekend).

Thanks all!

Maybe, maybe not, depends if you discharged your new battery so low as to do permanent damage to it's ability to hold a charge.
ricks99
Explorer
May 08, 2017
Well.... installed a battery disconnect switch over the weekend. I recharged the battery then turned the switch OFF. Battery should be good to to go until our next trip (Memorial Day weekend).

Thanks all!
1320Fastback
Explorer
May 05, 2017
ricks99 wrote:
Does it matter which terminal (+ or -) to attach to the disconnect switch? My first guess would be to run the negative thru the disconnect switch, but I'm not sure why....

My brand new, $180,000.00 Cummins powered forklift at work has it on the Positive Cable. It is a big heavy duty switch with about 4 large wires going to different parts of the machine.

Myself though on my personal vehicles I've always put it on the negative although I think my Toy Haulers stock disconnect is on the positive also.

Should be fine on either.
MrWizard
Moderator
May 05, 2017
Most people put it IN the negative...line as there is usually one thick wire to deal with, while the positive side May have several wires to put on the switch, to get everything disconnected
time2roll
Nomad
May 05, 2017
All OEM switches and fuses are on the positive. I would stick with that convention.
Only exception might be an uninsulated knife switch to go on the negative.
Electrically will be same result.
ricks99
Explorer
May 05, 2017
Does it matter which terminal (+ or -) to attach to the disconnect switch? My first guess would be to run the negative thru the disconnect switch, but I'm not sure why....
dewey02
Explorer II
May 04, 2017
ricks99 wrote:
The title says it all.... I returned from a weekend camping trip about 5 weeks ago. I was fully charged when I pulled into my driveway, unhitched, and put everything away.

Today, I went into the trailer to get ready for our next weekend trip, and had no power. The battery monitor in the power panel showed 1 light (out of four). But none of the lights would turn on (although all the indicators on my panel for water, black/gray tank, etc, all work.)

This is the original OEM battery. We purchased our HTT new in Oct.

I know there are some parasite drains, even when everything is turned off and I'm planning to install a battery disconnect.

DW and I are complete newbies and have no point of reference.... Is it normal for a battery to last only 5 weeks when parked?

Why don't you just plug it in while it is sitting in your driveway?
That way, your on board charger will keep your battery charged up.