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In RV park. Now have car to drive. Disconnect RV battery?

Cheryl_B
Explorer
Explorer
I've been driving my motorhome for all errands but now have a car to drive for the next 2 or more months. The rv battery is going to go dead just sitting here.

Do I have to start the engine every few days to keep this from happening, and let it idle for 5 minutes or so, or do I buy one of those trickle charge battery keeper things? I see them for about $30 but not sure if that's what I should do.

And how does that work anyway? What recharges the trickle charger?? Oy.
1985 Class C Chevy Rockwood, 27'
Fulltiming since June, 2016. Flying solo but I'm never alone.
Fear not the unknown, but the fear itself.
35 REPLIES 35

ronfisherman
Moderator
Moderator
Cleaned up thread. Please stay on topic and no personal attacks.
2004 Gulf Stream Endura 6340 D/A SOLD
2012 Chevy Captiva Toad SOLD

CharlesinGA
Explorer
Explorer
No need for Pea-ing matches here........

The OP is simply trying to decide whether to disconnect the chassis battery or not, and is probably open to other battery related maintenance issues. Best thing you can do is suggest to the OP specific products that will do the job.

Get a 120v powered battery tender, something that charges, watches battery voltage, turns off an on as needed to keep the battery fully charged, and probably has a desulfating cycle to help extend the life of the battery. Either run the tender off the power pedestal or an external receptacle on the MH and use a simple, cheap 16 gauge extension cord for that purpose.

The OP is not looking for million dollar ideas I suspect.

Northern Tool has a fairly highly rated Battery Minder that is 2 amp max, does a good job of keeping the battery charged and desulfating it. It comes with alligator clips and also adapters so it can be hardwired if desired. Its a little pricey at $80 but is a good unit. This will also be useful in the future when the MH is in storage and batteries need to be kept up.

http://www.northerntool.com/shop/tools/product_200483764_200483764

Charles
'03 Ram 2500 CTD, 5.9HO six speed, PacBrake Exh Brake, std cab, long bed, Leer top and 2008 Bigfoot 25B21RB.. previously (both gone) 2008 Thor/Dutchman Freedom Spirit 180 & 2007 Winnebago View 23H Motorhome.

IAMICHABOD
Explorer II
Explorer II
Or you can install a BIRD a Bi Directional Isolator Relay Delay

There are some brands that come from the factory with them already installed,Fleetwood products such as mine and some Winnebagos come from the factory with a BIRD and if the battery disconnect,on the power panel, is left on it will connect both batteries when not on shore power or generator.

It operates by sensing the voltages on both batteries.
When either of these voltages exceeds 13.3 volts for
approximately 1 minute, which happens when either battery
is being charged, the control will close the isolator solenoid,
connecting the two batteries together, charging them both.
(Normal charging voltages are from approximately 13.8 to
14.4 volts.)
After the solenoid has been closed, the system continues to
sense the voltage. If the ignition switch is off and the battery
voltage drops below 12.8 volts for approximately 1 minute,
which might occur when the converter is heavily loaded,
the solenoid is opened to prevent the chassis battery from
being discharged by the coach loads. When the voltage goes
above 13.3 volts again for approximately 1 minute, the solenoid
closes again. Thus always keeping the Coach as well as Chassis battery charged. Regardless of the parasitic draws on the chassis battery that run it down while sitting unused.
2006 TIOGA 26Q CHEVY 6.0 WORKHORSE VORTEC
Former El Monte RV Rental
Retired Teamster Local 692
Buying A Rental Class C

time2roll
Nomad
Nomad

Cheryl_B
Explorer
Explorer
🙂
1985 Class C Chevy Rockwood, 27'
Fulltiming since June, 2016. Flying solo but I'm never alone.
Fear not the unknown, but the fear itself.

harold1946
Explorer
Explorer
A simple trickle charger will work but needs to be monitored and shut off when fully charged.
There are also trickle chargers with overcharge protection.
A smart charger is a better choice if it is to be left unattended for a longer period of time.
There are small solar, (relatively inexpensive) chargers that come with a controller, and in my opinion are a better investment. I would suggest one in the 40 watt range.
No matter which application is chosen, it is always advisable to monitor, and check water level.
Harold and Linda
2009 CT Coachworks siena 35V
W-22 Workhorse 8.1L
Explorer Sport toad

Sully2
Explorer
Explorer
Sam Spade wrote:
Sully2 wrote:

Even disconnected electrically...a SMALL (1 to 1.5 amp) trickle charger hooked to that battery wont hurt a thing....and the battery will be up to 100 percent when you need it most


Not exactly.

A trickle charger left connected indefinitely tends to bring the battery up to a full charge and then OVERcharge it and cause it to lose water.

What is needed is a smart, automatic battery maintainer (battery tender). That is NOT a trickle charger.


All of the small trickle chargers I ever had personal dealings with ....had enough "memory sense" to shut off after 12.5 volts!:S That way any sever overcharging never happened. And when does indefinitely
ever enter into any RV picture
presently.....Coachless!...
2002 Jeep Liberty
2016 Ford Escape

Cheryl_B
Explorer
Explorer
I have an oldie but goody (which reminds me, I need to work on my signature.) 1985 Rockwood class C, 27'. Chevy. I never expected being plugged into shore power would charge the battery under the hood, but that would surely be nice.
1985 Class C Chevy Rockwood, 27'
Fulltiming since June, 2016. Flying solo but I'm never alone.
Fear not the unknown, but the fear itself.

Hikerdogs
Explorer
Explorer
It would be helpful if we knew the model and year of your motorhome. Many motorhomes prior to 2003 don't charge the chassis battery from shore power. Most of those after that date are supposed to. If yours is a newer model you may have something as simple as a failed isolation solenoid causing the problem.

If it's an older unit as mentioned I would have the battery tested before replacing it. If it's good and just gets drained too quickly it probably has a large a parasitic load. You could also have problems with the coaches charging system.

I was in the auto service repair business many years. I can't count the number of times people went to Kmart or Sears and purchased a new battery, only to have it dead in a couple weeks. In many cases it was the result of the alternator not charging the battery, either because it failed, or the belt was so loose it slipped under load.

At the price of batteries these days I would be sure you need one, and be sure the charging and electrical system are up to snuff to avoid ruining a new one.
Hikerdogs
2013 Winnebago Adventurer

Sam_Spade
Explorer
Explorer
Sully2 wrote:

Even disconnected electrically...a SMALL (1 to 1.5 amp) trickle charger hooked to that battery wont hurt a thing....and the battery will be up to 100 percent when you need it most


Not exactly.

A trickle charger left connected indefinitely tends to bring the battery up to a full charge and then OVERcharge it and cause it to lose water.

What is needed is a smart, automatic battery maintainer (battery tender). That is NOT a trickle charger.
'07 Damon Outlaw 3611
CanAm Spyder in the "trunk"

Sully2
Explorer
Explorer
Cheryl_B wrote:
Oh, cool. I'll have to see where to buy that disconnect switch. Thanks for the information, everyone.


Even disconnected electrically...a SMALL (1 to 1.5 amp) trickle charger hooked to that battery wont hurt a thing....and the battery will be up to 100% when you need it most
presently.....Coachless!...
2002 Jeep Liberty
2016 Ford Escape

Cheryl_B
Explorer
Explorer
Oh, cool. I'll have to see where to buy that disconnect switch. Thanks for the information, everyone.
1985 Class C Chevy Rockwood, 27'
Fulltiming since June, 2016. Flying solo but I'm never alone.
Fear not the unknown, but the fear itself.

lane_hog
Explorer II
Explorer II
I'm old fashioned -- have been pulling the negative battery cable for years until I finally bought a battery disconnect switch. Haven't had to jump the motor home since doing that...
  • 2019 Grand Design 29TBS (had a Winnebago and 3x Jayco owner)
  • 2016 F-150 3.5L MaxTow (had Ram 2500 CTD, Dodge Durango)
  • 130W solar and 2005 Honda EU2000i twins that just won't quit

klutchdust
Explorer II
Explorer II
My 09 Cambria chassis battery will go dead after about 3 weeks of non use. i purchased a 'smart 'charger and run it from coach power into a 12 volt accessory port.I used to use the HF float chargers but found one that was to hot to even touch plugged into the wall in my garage so they went into the trash. As far as the original poster and her battery issues. i used to test and switch out my own batteries, having AAA I now let them do it, their pricing is competitive, batteries guaranteed for 3 years and they do all the work. My coach batteries were a specialty item so i did those myself.