Chassis Battery Went Dead (I did a search but they said it's too old)

[steamyb]

My '98 Flair (30' model) is still not on the road. I finally got it back from the shop where they replaced front air bags and front shocks (rear shocks on backorder) and checked the LP system and wired the On-Demand Water Heater.
So now it's in the yard, plugged into 120V so I can do the last (hopefully) things to get it on the road. The original Water Heater had 120 or LP and the new Water Heater is LP only. What I want to do is run the old water heater wires back under the bed to power the Sleep-Number bed I bought. I also want to use this power to charge a Dyson cordless vacuum.
Well, the chassis battery went dead, I pulled it out to get it recharged and I'm told it's shot (1.2V showing on the gauge). So I buy a new one ($135), and within 2 days it is dead also. The starter won't even click. I'm thinking there is a solar panel on the AC lid that is supposed to keep these batteries charged up. I can start the engine with the coach batteries, but this can not be normal. I've read (and re-read) the manual on this thing, but it is so vague (they say that they make so many models, that they can not be specific to your model. They really should save some ink and paper on this manual and just tell you to watch youtube, you will learn more). So what am I missing here? I think I will charge this new battery and just not install it until I'm ready to roll. Problem is- what if I can't get back? Should I disconnect the ground wire on the chassis battery when parked at the campground? Is that normal? Is something in the camper pulling juice off the chassis battery that I am unaware of? And how do I stop that without having to get under the hood all the time? Thanks in advance for any help with this.

[nothermark]

Two day battery life is not normal or reasonable. OTOH did you charge your new battery after you bought it? Most are not fully charged when you buy them. They need hours on a charger or driving to bring them up to full.

Most chargers will fault on very low battery. The way to trick it is to use a large light bulb or similar in series with the battery. That limits the current while the cells re charge. Once the battery gets up to 12 v then switch to the charger only.

[JFNM]

Hi steamyb,

The tiny little solar panel on the air conditioner is too small to do much of anything but keep a fully charged battery "topped off" when there is no load. That is assuming it is still working (most likely, it is not after 17 years). I'm not sure which battery bank this solar panel is connected.

No, it is not normal to disconnect the chassis battery when parked for reasonable periods of time (a month). It sure sounds like you have something consuming chassis battery power. Finding these loads can be a challenge, it may help to view it as a mystery to be solved! Assuming the new battery was fully charged to begin, two days is relatively quick. I would get it fully charged, install, and then start searching for something that is powered up (and should not be). If you have a multi-meter, it may help to hook it up and find out exactly how much amperage is being drawn. This may lead you somewhere (meaning, if it is a very small amount (less than an amp), it may be radio, clock, etc.

Possibly a bit of humor - YouTube did not exist when your rig and manual were manufactured.

Good luck and keep us posted!

[Bigd9]

In addition to what nothermark said, check to see if there is any current leaving the starting batteries while the engine is off and the key is out. There shouldn't be any. It is possible the ignition switch is bad or stuck in the accessories or run position.

[Gary RVRoamer]

It may be that the old Flair's onboard charging system isn't working. As long as you are plugged into shore power, it should keep both house and chassis batteries charged up. It may also be that the house 12v is drawing power from the chassis battery as well as the house batteries and the onboard power converter/charger. If so, that could flatten a new battery quickly. It is not unusual in an older RV that has had wiring changed to get something connected to the chassis battery instead of house 12v system. A dead chassis battery is the common result.

[ga traveler]

Get a piece of number ten wire. Install a alligator clamp on each end. Hook it to the positive of both batteries. (house and chassis) both batteries are grounded to the frame, so you will not need a negative jumper. Now the chassis battery will be charged along with the chassis battery. Just put you a note on the dash to remove the jumper when you are ready to go.

[ga traveler]

Originally Posted by Gary RVRoamer

It may be that the old Flair's onboard charging system isn't working. As long as you are plugged into shore power, it should keep both house and chassis batteries charged up. It may also be that the house 12v is drawing power from the chassis battery as well as the house batteries and the onboard power converter/charger. If so, that could flatten a new battery quickly. It is not unusual in an older RV that has had wiring changed to get something connected to the chassis battery instead of house 12v system. A dead chassis battery is the common result.

Gary your coach is built for charging both batteries. Most low end coaches do not have this feature.

[wa8yxm]

I see the battery has been covered. you either have one heck of a "parasitic" load or the New Battery was bad.. I have had that happen.

On the 120 volt re-route.. Yes you can do that but consider this.

There is a device called a HOTT-ROD or HOT-Rod it is an electric heat element for your propane only water heater.. Cost is less than 100 dollars. Can pay for itself if you park at "Electric included" sites. Does not re-heat the water as fast as Propane does. but ... Keeps it hot very nicely. ... You can then Chain an outlet to the bedroom for the devices you cited there safely just use the same size wire that comes into the outlet (likely 12ga)

[kmx888]

How long should it take to charge 6 house batteries while driving? 2015 Expedition with a good sized alternator. Batteries low because of sitting for a couple of days with the residential refer working (on purpose). Drove 7-8 hours, alternator charging normally.
When we got to our destination I ran both furnaces all night, TV for an hour, Microwave for 10 minutes and of course the refer. In the AM batteries were just north of 11 volts
and the inverter has kicked off due to low voltage. Batteries started the evening at about 12.9VDC.Coach is only 6 months old, batteries always topped off and connectoins clean. It seems to me that this should be plenty of charging time.

[twinboat]

kmx888,
Your answer will be the purchase and installation of a battery monitor. Anything else is a guess.

Without knowing how much each furnace fan draws, they may have been the big power users, running all night.

[JFNM]

Originally Posted by kmx888

How long should it take to charge 6 house batteries while driving?

What is the size of the battery bank in amp-hours? What is the capacity of the alternator? How many minutes/hours was the alternator spinning at the RPM necessary to produce that output? What was the battery bank State of Charge (SOC) at the start of the drive?

Originally Posted by kmx888

When we got to our destination I ran both furnaces all night,

How many amps does each furnace draw when running? How many minutes were the furnaces running (actually blowing air)?

Originally Posted by kmx888

TV for an hour,

Is the TV AC or DC? How many amps does it draw when running?

Originally Posted by kmx888

Microwave for 10 minutes

How many amps does it draw when running?

Originally Posted by kmx888

and of course the refer.

How many amps does it draw when running? How many minutes was it drawing this current??

twinboat is right - get a good battery monitor (not a volt gauge). I like my Trimetric.

[pasdad1]

Usually better to run the generator and let the on-board converter/charger charge the house battery bank when it is very low. Alternator on engine is designed more to keep the batteries charged, than to replenish lots of amp hours.

[J-N-Lham]

I also have battery issues....
Chassie battery is less than 2 yrs old but holds charge for very short time.
House batteries similar in age less than 2
Solar charger on Air Cond.
I also have 2 disconnect switches above door. Turn off when not hooked to shore.
When not connected to shore power the chassie battery drops charge very quick, matter of days. even with switches switched to off.
Parts store where got battery (Gold) say must have phantom draw, said to disconnect positive cable and to connect test light to to neg terminal and other end to a ground to test, no light came on, so no draw? I guess.
Questions I have?
Any idea of whats going on?
I would like to hook a maintainer charger to chassie battery, can I do this with the house batteries connected.
I think the book says I need to have the switches (above door) off when charging?
Can I use a 12 volt charger connected to chassie battery and charge all three, the house batteries are 6 volt golf cart batteries connected in a series giving 12 volts. Want to do this to bring all batteries to full chg. for the maintainer.
Ultimately I will bring all in house and charge as needed, winter just got here too quick.
Thanks
2005 35E Bounder Ford
2012 Jeep Wrangler Toad

[Bigd9]

Originally Posted by pasdad1

Usually better to run the generator and let the on-board converter/charger charge the house battery bank when it is very low. Alternator on engine is designed more to keep the batteries charged, than to replenish lots of amp hours.

A lot depends on your RV. On mine, the engine alternator is rated at 160 amps. The generator produces AC voltage that goes to the inverter/charger. It only puts out somewhere around 100 amps max.