Okay so I was asked to be an assistant scout master last summer. Our troop camps every month, year round regardless of weather. Thankfully leaders are not required to tent it so I bring the camper along for all of the leaders.That has meant that when I winterized this year I only drained the water and such. I left the camper plugged in all winter and left the fridge running so there would be some draw on it.When I went out to check on my batteries today I have all sorts of corrosion and it took 5 bottles (17oz) to fill them up!!!I'm running dual 6V's I want to say they are about 4 years old at this point.Do you think I'm still good or have I toasted these and need to replace them?

Check voltage is 13.2 to 13.5 and how full are you setting the water?s/b 1/4" to 1/8" below the split ring that extends into the cell. Just touching is absolute max and may still push some water out. Otherwise the batteries might be shot.How often do you run them below 12.0 volts?Designing and installing ~200 watts of solar could be a project toward the electrical merit badge.

2 quarts plus of water. much corrosion. The batteries are damaged. Four years old. A real long-shot they can withstand the rigors of a long camping trip. Only you can call the shots on a coin-toss decision for new batteries.When storing the rig...Buy a BATTERY TENDER and plug it in.UNPLUG the rig to neuter the converter.Only use the converter for short sessions. No more than one week plugged-in with discharged batteries. No sense in spending a lot of money for a tiny bit of camping-time service.

Naughty boy.. you didn't check water all winter. Probably shot. is there any bulging? That's a sure sign they're toast.Anyway, charge them up, and let 'em sit an hour then run something. Then check voltage.

MEXICOWANDERER wrote:2 quarts plus of water. much corrosion. The batteries are damaged. Four years old. A real long-shot they can withstand the rigors of a long camping trip. Only you can call the shots on a coin-toss decision for new batteries.When storing the rig...Buy a BATTERY TENDER and plug it in.UNPLUG the rig to neuter the converter.Only use the converter for short sessions. No more than one week plugged-in with discharged batteries. No sense in spending a lot of money for a tiny bit of camping-time service.What he said.I would only add: Put the battery disconnect switch to OFF and connect the tender directly to the batteries.

HeathJohnson wrote:Okay so I was asked to be an assistant scout master last summer. Our troop camps every month, year round regardless of weather. Thankfully leaders are not required to tent it so I bring the camper along for all of the leaders.That has meant that when I winterized this year I only drained the water and such. I left the camper plugged in all winter and left the fridge running so there would be some draw on it.When I went out to check on my batteries today I have all sorts of corrosion and it took 5 bottles (17oz) to fill them up!!!I'm running dual 6V's I want to say they are about 4 years old at this point.Do you think I'm still good or have I toasted these and need to replace them?Replace them.All last summer you boiled the electrolyte away by using the alternator/VR to charge deeply discharged 6V deep cycle batteries. Once most of the electrolyte was boiled off the individual plates would have begun to warp and short.You may be able to recover to a 12.6 voltage level but in all likelihood you have lost ampere/hours. That is a VOLTAGE regulator, it will put out MASSIVE levels of current, limited only by engine RPM or maximum alternator rating, in order to maintain the voltage at 14.4 VOLTS.DO NOT connect deeply discharged deep cycle batteries to an automotive alternator/VR system. Connect a 500W inverter to the alternator/VR system and run the 120 VAC output to the RV converter that will regulate, limit, the battery charge rate.

Battery help please. | Good Sam Community

20 Replies

Vulcan_Rider
Explorer
Jun 15, 2015
Chandalen wrote:
A trickle charge, or a once a month charge and check is fine.

Once again: An unattended "trickle charge" with an inexpensive "dumb" trickle charger.....or converter......over long periods is not "fine".

What the OP reported here is exactly what you should expect to happen and it is NOT good. Even if the battery structure or chemistry is not significantly damaged, just the corrosion is a huge pain in the butt and can eventually cause things like battery trays and mounts to fail.
Chandalen
Explorer
Jun 15, 2015
I'm confused why you wanted a draw on the batteries? A trickle charge, or a once a month charge and check is fine.

After filling with water, did you check the voltages of the batteries? If so.. what were the voltages?

It sounds like -if- they hold a charge still, they should not be counted as good batteries.
wa8yxm
Explorer III
Jun 15, 2015
Vulcan you may have posted the qustion but the O/P has not responded.

Oh and I see many of you saying 2 quarts of water means batteries are damaged.. yes, might have taken a month or two off their total life.. Two quarts is about the maximum you can add to a GC-2 pair before damage sets in but I would not call them toast based on that.

IN fact I had to add about 2 quarts a year to mine.. that would indicate (At least on my interstates) the fluid level in the battery was JUST at top of plate level.. That is the absolute MINIMUM level without damage.

To the original poster.. There are many convrters.. IF you have, for example, a Magneteck 6300 series power center/converter assembly then leaving the fridge on (or lights or most anything save the radio) while plugged in had no effect on the battery charging.

and the Magnetek is very well known for doing what your convertr did.
The magnetek has two sections.. A converter that powers most of the stuff in the RV when pluggd in, and a battery over-charger that does what happened to your batteries if left plugged in long enough.

MOre modern convrters (Say parallex (Who bought Magntek) 7300 are also not that good at long term charging but still can cuse the kind of damage you describe.. Just takes longer.

Finally we have decent 3-stage converters In the 45 amp range "Multi Hundred Dollar" price tags means someone is goughing you 150 is closer (157 at best converter for a 9245 deck mount)
or if fixing a combo power/center converter you can go with the 4600

http://www.bestconverter.com/PD-9245C-45-Amp-RV-ConverterCharger_p_170.html
time2roll
Nomad
Jun 15, 2015
Here is some easy reading:

The 12 Volt Side of Life
Vulcan_Rider
Explorer
Jun 15, 2015
wa8yxm wrote:

The convrter is suspect.. Make and model please.

Thought I posted this already.....????

How the converter was USED is suspect.

Most inexpensive units are not intended to be left on all the time and are not "smart" and will just blindly keep charging away whether it's needed or not.

It's fairly common knowledge that long term use of a dumb trickle charger is not good. When the battery gets fully charged, even a small charging current will "boil" off the water over time (a very slow electrolysis actually).

And I agree that leaving the fridge on is just a waste of energy.
It probably didn't make any difference in what happened to the batteries.
burlmart
Explorer
Jun 15, 2015
several hundred for a multi stage converter may be overkill for a light use rig

many have reported that the cheap battery tender can totally discharge your batts and kill them if shore power goes out for a while. this sounds suspicious, or maybe it was an oversight now corrected. for a hands off approach to charging, check into this possible killer.

simple converters like the parallax units do reduce the charging amps as batts near full charge. in a hands-almost-off scenario, i'd put a note on fridge to charge on 1st (and 15th if you really want happy batts) for 24 hrs, run whatever you want, but turn it all off when the charge time is up.

batteries should not boil, and this should work well for your batts that may be saved. total cost is $0
red31
Explorer
Jun 15, 2015
HeathJohnson wrote:
left the fridge running so there would be some draw on it.

WHY? I bet if you turned the fridge OFF you'd not have this issue unless the batts are bad.
wa8yxm
Explorer III
Jun 14, 2015
Your 12 volt system has several parts

A CONVERTER (Make and model please)
A Battery (you described them well enough)
A switch or solenoid (not the problem)
and assorted loads (No description needed)

The convrter is suspect.. Make and model please.
doughere
Explorer
Jun 14, 2015
"When I went out to check on my batteries today I have all sorts of corrosion and it took 5 bottles (17oz) to fill them up!!!"

5 17oz bottles of water is a lot. If you let the tops of the plates go dry, you're probably in bad shape.

If the tops did not go dry, then you're probably OK. GC batteries can take a lot of abuse (that doesn't mean you need to abuse them though). Clean the corrosion up, and do a load test; see how they work.

You probably ought to get a battery disconnect and a battery tender. A good three stage converter would be nice, but a disconnect and tender will do fine if used regularly.

Doug
Vulcan_Rider
Explorer
Jun 14, 2015
westend wrote:

With a bank of two-6V's it will be wrong almost all the time.

If the batteries are discharged and the RV is returned to storage, the battery "tender" will not charge the batteries correctly.

RE: being "wrong": it might not be optimal but being off just a bit from optimal is usually insignificant.

And whether or not the tender will recover from a near to complete discharge.....that depends on the tender in question and the time frame available. Many won't; some will.

It is a matter of preference.
Both options can work fine if done right.