Batteries 101

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ROVER

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Aug 7, 2005
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Hello All ...

Had some time this past weekend to do some maintenance on ROVER. I'd noticed that the auxiliary battery was not recharging when plugged in to the campground outlet, so I checked the water level in both batteries and found all cells to be almost dry. I added distilled water to the fill marks. The auxiliary battery is two years old, according the the previous owner. How often should the aux battery be replaced? Should I suspect problems with the converter in that it is not recharging the battery?

When I bought the motorhome ('89 Ford Econoline) I was told that the battery on the driver's side was the aux battery. It has a multitude of wires running to the hot post, whereas the other battery has maybe two wires running to the hot terminal. I tried to trace the starter wire but things are so tight in the motor compartment that I couldn't follow it.  Am I correct in believing that the aux battery is on the driver's side? I am not familiar enough with Ford products to know which side the battery is normally placed on.

Thanks in advance for the info/advice...

Chas

 

Tom

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Chas

Allowing a battery to run dry isn't a good thing, but I've never found it to cause complete battery failure, especially if the battery isn't being charged. Adding water and recharging has usually brought a battery back to useable condition despite everything you read to the contrary.

A deep cycle (auxiliary) battery should be good for at least 5 years and I've had them last a lot longer.

Do you know for sure you have a converter on the motorhome? If you can locate it, can you tell us what make/model it is? Some of the older converters were notorious for overcharging batteries to the point of water being boiled off and eventually the batteries failing.

You should be able to tell which is the starter battery by the two very heavy wires.
 

ROVER

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Aug 7, 2005
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Tom:

Thanks for the reply.  The unit (looks like a sheet metal box) which I believe to be a converter is located at the back of the motorhome, beneath the bed on tne driver's side. It is accessible via a panel at the base of the bed, or from the outside where one opens up the little door to pull out the electric cord and plug to plug it in at the campsite. (I guess you could get to it from the outside if you had really long arms...)!  When plugged in to electric service, I can hear a soft "hum" coming from the unit and my "battery " indicator on the systems panel shows a full charge.

Although ROVER came with a collection of manuals, there is not a manual or any info on a converter. I will get under the bed to check out make/model if I can find them.

Chas
 

Tom

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Chas

Sounds like you might have the older style converter which doesn't control or limit the charging current. There are alternative chargers available that coukd be discussed if you want to go that far.
 

John From Detroit

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Tom said:
Chas

Allowing a battery to run dry isn't a good thing, but I've never found it to cause complete battery failure, especially if the battery isn't being charged. Adding water and recharging has usually brought a battery back to useable condition despite everything you read to the contrary.

If you let a battery run dry and stay that way too long bad things happen to it, Those plates are really not designed to be exposed to "air"  I have seen it happen a few times

And to the original poster.. Sounds like this is what happened.

Every trip: Check battery level,  Top off as needed.  Every "end of season" check and fill if needed, charge if needed (plug in),  Every month or so when stored check and charge if needed,  Use a hydrometer (Test the specific gravety) of each cell, when putting away and when "Waking up" for the season, You can just check one cell during the storage period.

Note: Unless they are "Maintance free" you should check not only the aux batteries, but the chassis (engine) battery, and your car's and your spouse's car and any other wet-cell batteries you have while you are at it.  Nothign like a dead battery to ruin a day (or a flat tire, or an empty gas tank or some other vehicle failure)

heck, one day for me it was a broken ignition switch, however though for my wife that was a disaster, for me it was a minor issue as I had a steering wheel puller (still do) and it was a matter of just a few minutes work to pop the wheel, push the release button, pull the broken cylinder put the wheel back on and fire the car up with a "Detroit Key" (Flat blade screwdriver).  Wife never did figure out how I knew to do that (I am a fully trained car theif, trained by the best, Michigan State Police.... I've just never stolen a car is all)
 

Tom

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John In Detroit said:
If you let a battery run dry and stay that way too long bad things happen to it

As I said John, I've seen "dry" batteries come right back to life after adding water and re-charging on many occasions, although I don't recommend consciously allowing them to run dry. FWIW water below the visible top of the plates does not mean the plates are completely dry. e.g. the deep cycle trolling motor battery on my bass boat had sat for many months without adding water or re-charging and, when I checked a couple of months ago, it appeared the plates were "dry". However, since the battery case is translucent, I was able to see that the water was virtually to the top pf the plates and they were not dry at all. Adding water and re-charging followed by a hard couple of daya of fishing/trolling confirmed the battery was unharmed.

The point of my response to Chas was that he shouldn't assume the battery is dead and buy a new one without first trying to revive it.

I can't figure out what a broken ignition switch has to do with it  ???
 

Ron

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Quite a bit of information regarding batteries and different type of batteries, Gel cel and AGM can be found at the following link.
http://www.eastpenn-deka.com/products/pdfs/0139.pdf

 

John From Detroit

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Tom said:
As I said John, I've seen "dry" batteries come right back to life after adding water and re-charging

Same here, And I've seen them where they did not.

The only point here is that if the battery died early... That MIGHT have been why.

Also, it may have been frozen while not charged (Also not a good thing, charged they are very hard to freeze, discharged, much easier)
 

Gary RV_Wizard

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Some inexpensive brands of batteries will last only 2-3 years, especially if not maintained properly. Many 12 volt batteries sold as RV or marine batteries are combination deep cycle and starting batteries rather than dedicated "deep cycle" designs and not really good deep cycles.  I would not be surprised if your batteries are pretty well shot.

If yours is a 1989 model RV, it will almost surely have a mediocre quality converter/charger that will consistently overcharge the batteries and boil off the water from the cells. Check the water level frequently - at least monthly. Better yet, replace the converter/charger with a new one by Progressive Dynamics or Iota and get rid of the overcharging problem completely. Figure $175-200 for a replacement.
 

ROVER

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Aug 7, 2005
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Gary:

As far as I can tell the converter is the original, as are most all of the other systems components in the coach. Replacing the converter is high on my list of priorities. Is this a project I might tackle myself? I know that's a tough question, as my level of expertise comes into play. I am comfortable with replacing light fixtures, switches, etc. around the house. But I don't fool with any heavy-duty electric work...i.e., I hired an electrician to upgrade the electric service.

Considering ROVER is an '89, what other items should be on my "watch" list.? The only thing I can find that does not work is the generator, which turns over but does not seem to get gas. The gas tank is 3/4 full so theoretically it should fire up. The fellow I bought ROVER from owned him from '99, and said they had never used the generator as they only parked where they could hook-up to electric and water.

ROVER has 48,000 miles clocked up and is in very clean condition inside and out.  He joined our family at the beginning of this month and has already given us two great weekends at parks within an hour of home. In September we plan to let him take us about six hours away, so I'm trying to get everything checked out before the trip.

Eastward Ho!

Chas
 
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