Ford Chassie Battery

[John S.]

Well, we just got back from a week trip that lasted 7 weeks. I went to start the BFT and the Chassie battery was dead. Nothing was left on inside. I can not believe that the clock was the only thing that is drawing power. I will have to put a meter on and check and see if I can find the draw by pulling fuses. I just wonder if anyone else has had the same problem. The house batteries were fine. I had it in the garage and it was heated as well. The trucks all started with no problem.

I put on the charger and it came back up.... Will load test it tomorrow and see if it is the battery or not after i run it for a while.

John
2006 BFT

[jobrien]

I can share my experience.

My chassis battery kept going dead. When it was at the factory, they were kind enough to bring it to a Ford dealer there. They (I believe it was the factory, not Ford)determined it was the dash radio, which is fuse #20 that had the only draw on it. The battery passed a load test.

After getting it back in NJ, the battery again went dead. I took it to a local Ford dealer, who also verified the problem was in the dash radio. They disconnected the radio while waiting for a replacement. It took 2 months to get a new radio, and during that time the BF started every time, even in very cold weather.

The radio was just replaced yesterday, so I can't tell you if it is fixed or not. But in a few days I will attempt to start it and see what happens. If it continues to fail, I will call Ford road service every time until they get tired of coming out to jump start it, and really fix the problem. But I am hoping the radio was the culprit.

In case you did not know it, if you want to jump start it from your couch batteries all you need is 1 cable from the positive post. The negative side is common to both sets of batteries. I believe an 18' length is sufficient. I always carry mine with me.

Hope this helps.

John

[John S.]

Thanks, I wondered if that was the culprit. I have a portable jump system so thanks for the heads up on the way to jump from the other batteries.

[carl brenneman]

I too had large voltage loss in 3 weeks of idle time on my 1 year old battery. It would drop from fully charged at 12.62 volts to under
12 volts (using precise digital FLUKE meter). The solution for me was
to disconnect the NEG Ground cable while it sits dormant. I discovered that during idle time, the battery is being drained at the rate of
12 milli-amps. A small current but over 3 weeks takes the battery down pretty far. Hope this helps for those having the same problem.

Carl
2004 BF

[John S.]

Before jumping to any other conclusion, see if the battery will hold a charge. If not, replace the battery.
Batteries are sometimes defective......even though near new.

Got a friend who is a workhorse and ford warranty center to look at it on wedsday and he had a tool that checks batteries if they have as little as one volt and low and behold it was bad. So it was replaced under warranty. They also had a wiper motor recall when we went in we handled at the same time. Now I will see if this lasts.

[carl brenneman]

Sam, I noticed you are saying "Motorcraft" Battery.

My rig has an Interstate Battery. Also, when I discovered the large drain, I disconnected the Neg (Ground) cable and watched it for about four weeks and the battery voltage only dripped less than one tenth of a volt during that time with no connections. So, I concluded to save the battery
I will not stand idle more than 3 weeks with the battery connected. We do go out every month for 3 or 4 days so mine will be ready each time.

Carl

[whemme]

carl brenneman,

Actually a 12 milliampere drain on the chassis battery should not be a problem with the coach sitting for 3 weeks or more. I am not sure of the actual AMP-HOUR rating of the E-350/E-450 gas chassis battery but I would guess it would be in the area of 100 amp-hours. Dividing that 100 amp-hours by the 0.012 amp residual current drain means that a fully charged battery in good condition would fully discharge in 100/0.012 = 8333 hours which is 347days (50 weeks).

Now I know that lead-acid batteries also self-discharge on their own without the 12 milliampere drain that you measured. If we assume a self-discharge rate of 38 milliamperes plus the 12 milliampere external drain that you measured for a total equivalent drain of 50 milliamperes, it would take 2000 hours or 83 days (12 weeks) to fully discharge the battery. This battery after only 3 weeks should have retained a 75% charge which should easily be able to start the engine.

Others may have a different opinion about this.

[norijake]

Here is a website that may be interesting to those who wish to understand battery dscharge rates. There is a link to a Peukert calculator written in MS Excel (you can either download it or run it online). Playing around with the numbers, some may find it informative or just fun to learn how a particular battery is supposed to discharge under a given load.

http://www.smartgauge.co.uk/technical1.html

I found this site extremely helpful in designing and building electrical systems for several older boats I restored.

[jobrien]

Update to my battery situation....

As posted earlier, Ford determined the problem was in the dash radio. It was replaced under warranty on 3/16.

I started the motorhome last wee on 3/23 and it ran for about 45 minutes. Went out today to start it and it was dead. Battery read 10.29 volts and the little battrey indicator light was green. I called Ford customer service/road service and they told me to bring it back to the dealer. DUH

I told them I needed a jump start and they dispatched someone out to jump it. I figure if I do that enough times, maybe Ford will get tiored of paying for road service and will find the real problem.

I will call the local Ford dealer on Monday and see what their next step is. I will ask for a new battery, but their position is if it passes a load test it's good. So we'll see where this goes. I'm sure 2 road service calls will be more expensive than a new battery.

John

[KTnLen]

Just a thought from my own recent experience: we tow a car hauler trailer behind our 32-ft President, and so have a Prodigy Brake Controller installed with control unit mounted to the bottom of the dash. Well, after having to boost start the rig twice, it finally dawned on me to disconnect the controller unit from the electrical when I won't be using the coach for more than a week, and I haven't had any drain or starting problems since.

I noticed you have a toad as well, so just wanted to offer up this possibility. Len C sends.

[bcope01]

There is a short draining the battery.

And it could be internal to the battery, too. Just another thing to check out.

Bill

[jobrien]

June update

Got the motorhome back from Ford this past Saturday.

They replaced the instrument cluster and installed a new battery. We'll see if this fixes it or not.

John

[Trisha]

I hope it works. I read a lot of stories here about little things discharging the chassis battery.

Well, I have left my BF for up to three months, with nothing unplugged at the fuse, without starting it. In VERY cold weather. I walk out after 3 months, turn the key, and she starts. End of story.

Coach is 2 years old. So battery is at least that.
Nothing unplugged, nothing unhooked. Not started and run. Below Zero temps. No gas on startup.

Yeah, it was a *little* sluggish, like for one second. then Vrooom!

So that is what I expect from a battery, because that's what I have experienced so far.

If that isn't your experience, I guess it can be agreed that there's something wrong with the battery system if it doesn't work this way. This is my yardstick and I'm sticking to it.

Trish

[jobrien]

Trish;

I hope it works too

What year is your chassis?

John

[Trisha]

I have a 2005 26' RB. I purchased it in April of '05 off the showroom floor. It was built in February of '05.

I guess you could call it dumb luck. Nothing seems to ever drain the battery to the point it more than sluggish, and sluggish I expect. I rarely leave it that long without going in it, running it a while (on the road). But this last winter, well... it was a long winter.

The coach batteries, in spite of a few newbie mistakes, have also done well. i don't usually disconnect them and they can go a month or more without draining. I do go in, try lights, and sometimes run the fantastic fan.

Again, I prefer to run it for a bit, on the road, at least once a month, but sometimes events conspire against me. At least the batteries haven't conspired.

Beats me why batteries sometimes act badly. Maybe they're defective. But I don't seem to have problems with things draining them, and most of our coaches come from the factory with similar things.

Maybe there's a thing called a battery fairy, and I have accidentally made her happy.

trish