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

[ricks99]

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?

[mike-s]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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.

[1320Fastback]

Check on the tongue near the batteries, there may already be a disconnect switch installed.

When I park my trailer after it's unloaded I pop the disconnect. Usually plug it in 2 days prior to departing to get refer cool and batteries topped off.

[wa8yxm]

There are several things that can affect "Shelf life" Including how hot it is out and a few other things

But if you take the time to LIFT the netative cable off the battery terminal so it is FULLY disconnected.. and if it is FULLY charged before you do that

4-6 Months.

Hook up a battery maintainer 7-10 years

[ricks99]

Thanks all, OP here, now I know. 🙂

This is our first trailer... at PDI the dealer suggested disconnecting the batter at the end of the season, but I don't recall anything about disconnecting between trips.

I've added a battery disconnect switch to my "to-do" list.

[DutchmenSport]

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...

True story: 1984 I was slated to go to Korea for a year in the Army. I left February 1984 and came home February 1985. My car sat in my mothers garage for the entire year and was never started. When I returned home, the first thing I did was try that car and see if it would start. Unbelievable, it still had enough juice in that battery to turn the engine over. Although my mother said no one ever started it (and she did not drive and would do it either), I can only assume, that maybe someone did start it. Still, I got the car running and drove it with the same battery for another year before I crashed it! (True story!... really!)