RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×

Thread Tools Display Modes
Old 09-29-2009, 10:14 PM   #1
Junior Member
Join Date: Sep 2009
Location: Rockford, IL
Posts: 10
Advice on more battery power

Have 1998 Sportsmobile with 4 cubic foot refrigerator and propane furnace and one battery. This summer while on vacation in the mountains had difficulty because frig was using so much power that safety feature on the furnace would not allow furnace blower to operate; i.e. cold in the morning.

Found this out when talking with a service technician for furnace supplier. Glad it worked as it did, but here is my problem. My wife and I like our food cold and our Sportsmobile warm in the morning. (i.e. we also have an Onan 2.8 generator, but was unable to use it because of campground regulations.)

Have considered 2nd battery because I've seen so many newer Sportsmobiles have two batteries. Is this the best answer? Before I blindly spend additional $500 to have 2nd battery I thought I'd ask for advice. Thanks in advance.

mobilemaster3416 is offline   Reply With Quote
Old 09-29-2009, 11:13 PM   #2
Senior Member
scatter's Avatar
Join Date: Apr 2007
Location: Blairsden, CA (when not on the road)
Posts: 1,087
Re: Advice on more battery power

There's always solar. But if your battery is pretty much full at night and down in the morning, the only answer is to use less power or get another battery. You sure your existing battery is in good shape? I have the small fridge, but am only down 23 amp-hours in the morning using the fridge and lights. One battery is more then I need. Check your battery and there's several meters out there that will check power draw to be sure your fridge is using what it should.

You can be anything you want on the Internet,
it amazes me that so many choose stupid....

2007 RB50, 6.0
scatter is offline   Reply With Quote
Old 09-29-2009, 11:34 PM   #3
Site Team
daveb's Avatar
Join Date: May 2007
Location: Turlock Ca
Posts: 10,004
Re: Advice on more battery power

It depends on what battery you're using now. Is it a 4-D and how old is it? I assume you have one because you state 500 bucks for a second. Most folks find a single 4-D is good enough for a single night provided you travel the next day or have some solar to help out. Maybe your battery is ending its life or something is pulling more than it should off it. Have you kept the battery fully charged when the van sits idle? A month at 60% will take a toll on a AGM battery.
Provided you've kept up on the correct maintenance like charging, connections, and how low you have taken it down, two batteries might be a good choice. Make sure there isn't another problem causing you to loose power.

You'll need the space to add a second and it's a good idea to have them mounted close to one another to keep the buss short. Adding a second new battery to an existing old battery is a poor move. They should be the same make, model, and age.

I would hate to see anybody spend the bucks to retrofit their rig only to find 2 batteries have the same problem. You can also go with a slightly larger single battery like an 8-D but two 4-D's are more amp hours. If you need more info PM me and I can send you some good links.
Hope this helps...DaveB
2006 Ford 6.0PSD EB-50/E-PH SMB 4X4 Rock Crawler Trailer

Sportsmobile 4X4 Adventures..........On and off road adventures
daveb is offline   Reply With Quote
Old 09-30-2009, 10:47 AM   #4
Senior Member
yvrr's Avatar
Join Date: Oct 2007
Location: Newark, CA
Posts: 795
Re: Advice on more battery power

If your setup worked in the past but doesn't now, the battery might be getting near the end of its life, the refrigerator is causing the problem, or there might be a grounding problem with the battery. We had a 4 CF Norcold and it did seem to start drawing more power after several years of use. You might start by checking out the door seal. Take a dollar bill and close the door on it. When you pull it out, there should be a little resistance. If not, the seal might be getting old and brittle. You can replace it with a new seal which is easy to do. However, when I tried to do this a few years ago, the replacement seal I received was worse than the one I was trying to replace and I gave up on it. Someone mentioned on a past post that the compressors in these units are not the best and inefficiencies due to age could make the unit draw more power.

I'd start by checking out the refrigerator and seeing if you can determine why it might be pulling more power now if it is fact doing that. Next, check the cables serving the house battery and make sure that they are in good condition and not worn through which could cause the battery to ground out. How old is your battery? If you decide to add a second battery, both probably need to be new at the same time. So, you could first purchase a new one and see if that solves the problem. If not, you'd be in good position to add a second new battery. At that point, the other option is to replace the refrigerator.

For comparison purposes, we had a 4 CF Norcold and a single 4-D battery. Six months ago when I took some measurements on it, the battery was about 1-1/2 years old. With no lights on (these tests were done in the driveway and not while camping) and with the refrigerator at 6 o'clock, the house battery would drop to 12.2v in the morning. The battery is now 2 years old but with the Isotherm refrigerator (which doesn't draw down the battery at night), we will be at 12.4v or higher in the morning even after the furnace has been running for 2 hours.
'01 Ford EB50p Quigley 4WD
yvrr is offline   Reply With Quote
Old 12-26-2009, 09:43 AM   #5
Senior Member
jage's Avatar
Join Date: Apr 2007
Location: Franktown, CO
Posts: 7,602
Re: Advice on more battery power

I agree with the bad battery theory too, I have a bad 4D and added a second new 4D (because of power consumption calcs, not that I knew the first was bad) and the two of them got worse and worse to the point that putting the top up would knock me down to 10v.

If you do get double batteries (not that it sounds like you need them) replace both at the same time, don't hook a new to an old like I did, because it won't turn out well.

Incidentially after abusing the new 4D by having it with the old one, I've disconnected the old battery and with the large Norcold, furnace and power top I've been fine (although I haven't been using my toaster, which is the root of my power consumption needs).
and then
everything changed
jage is offline   Reply With Quote
Old 12-26-2009, 12:17 PM   #6
Senior Member
Join Date: May 2009
Posts: 1,762
Re: Advice on more battery power

mobile master

here is what i would ask:

brand battery
size or model #
amp hours if ya know
location of battery now
what else ya got slung under the rig
floor plan
type and model fridge
type and model heater
PH or hard top
solar if any

bw out and on the way to Joshua Tree

billwilson is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Powered by vBadvanced CMPS v3.2.3

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.

All times are GMT -6. The time now is 10:51 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.