hpcrank

[hpcrank]

We just aquired (last fall) a 1989 GMC Topkick with a 12' Aero Lite conversion. It lives in a garage and we have been pulling it out every 3 or 4 weeks, letting it run and driving around the section a few times. Last time when we put it back in the garage we opened the battery bay to hook up a trickel charger and noticed that the battery for the on board Ownan generator was smoking. We removed the smoking battery and noted that the battery cables and terminals were not excessivly warm. The battery is a sealed conventional 12v. DC automotive type battery.

Two questions 1) what would cause the battery to smoke other than a direct short to ground? and 2) are most generator batteries charged by the truck when running or by the generator set itself? Our generator battery has a + cable thru an automatic re-set circuit breaker to the parallell connected truck batteries +, is that normal?

New to this so any advice would be appreciated.

[Bob86ZZ4]

Wow, that's scary a smoking battery. My truck batteries start the generator and when the generator is running it will charge back those truck batteries that started it. Mine is an Onan diesel unit. I'm pretty sure most of them do that. I'd suspect a failure in the battery since I doubt if anything was changed in the wiring lately. Can you take the battery to a store and have them hook up their tester and see how it looks to them?

[#90-GTSC]

Let us know what you find out.

[bushpilot]

was it SMOKE (from where) or misting battery acid (neither is good).
even SEALED (lead acid) batt's can be checked for fluid.

i would IMMEDIATELY pull that battery and test it, and check to see if its been "boiled" dry by the charger.

i NEVER EVER use a trickle charger - they will over charge a battery and boil it dry....
the internal chargers in most coaches are trickle chargers and need monitoring of the batteries to make certain they do not boil the batteries dry.

when i park our coach i disconnect the batteries and connect an INTELLIGENT battery maintainer (battery tender or battery minder) - intelligent chargers will adjust their charge output based on the batteries condition (lowering the change when the batter is "topped off").

[Bob86ZZ4]

Good call, Don (bushpilot). I forgot about that one. My first camper, an Allegro class A, had an old fashioned charger converter in it. No circuitry to monitor anything. Huge thing that looked like you could probably weld with it. That first winter I kept it plugged in all winter and dried up 4 golf cart 6v batteries. Took it out and put in a expensive one that wouldn't overcharge them.

[bushpilot]

yup sounds like the same pos that is built in, in our coach.
if im in "camp" connected to shore power i disconnect the batteries (by switch).

in my storage bay, even w/ shore power, i disconnect the batteries and keep 'em on "smart" chargers

im a huge fan of intelligent chargers....

ive got a few motorcycles that are on intelligent / smart chargers....sometimes years go by w/out starting 'em...and they always start right up...

I even use one on my f350....i managed to get 7.5 years out of the OE factory batteries as a result.

[#90-GTSC]

Originally Posted by bushpilot

was it SMOKE (from where) or misting battery acid (neither is good).
even SEALED (lead acid) batt's can be checked for fluid.

i would IMMEDIATELY pull that battery and test it, and check to see if its been "boiled" dry by the charger.

i NEVER EVER use a trickle charger - they will over charge a battery and boil it dry....
the internal chargers in most coaches are trickle chargers and need monitoring of the batteries to make certain they do not boil the batteries dry.

when i park our coach i disconnect the batteries and connect an INTELLIGENT battery maintainer (battery tender or battery minder) - intelligent chargers will adjust their charge output based on the batteries condition (lowering the change when the batter is "topped off").

Why don't you leave the batteries "hooked up" and have the INTELLIGENT battery maintainer permanently hooked to the batteries? When you camp or store the coach, the motor is shut off and alternator isn't trying to put a charge into the batteries. Then when you plug in shore power, the INTELLIGENCY battery maintainer goes to work. When you leave, you unplug shore power.

Unless I'm missing something (and that is quite possible), I can't see why you unhook the batteries. Thanks!

[daddywoofdawg]

My three guesses would be one, mice could of chewed on some wires and it shorts,or the alt charged the battery even though it was fully charged.3.would Be the battery shorted inside the case.Take it to a auto parts store and they will check it for free.

[bushpilot]

Originally Posted by #90-GTSC

Why don't you leave the batteries "hooked up" and have the INTELLIGENT battery maintainer permanently hooked to the batteries? When you camp or store the coach, the motor is shut off and alternator isn't trying to put a charge into the batteries. Then when you plug in shore power, the INTELLIGENCY battery maintainer goes to work. When you leave, you unplug shore power.

Unless I'm missing something (and that is quite possible), I can't see why you unhook the batteries. Thanks!

1) because i trust NOTHING and batteries are expensive
2) i believe my ac to dc inverter charger MAY boil my batteries dry....even though i keep a close eye on my battery water level AND we use our coach mor e than most...at least once a month !

when we are on SHORE power our inverter TRICKLE charges the house batteries (not the engine batteries).....again i dont want to risk boiling our
9 batteries - when i can disconnect them (call me overly paranoid or ANAL) and INTELLIGENTLY charge them myself.

[hot rod]

I had a similar problem in my trailer. When I bought it the previous owner had wired it with an older Magnatec 45 amp charger/12v power supply. One week it decided to start putting out too much voltage, and overcharged and cooked my 2 nice new deep cycle batteries.

Shopped around, and Magnatec is now Parallax, and the equivalent unit is now a 7345. I looked into better things, but rewiring would have been a pain. So they have the 7345RU which is basically just the replacement "guts" for the unit, you just change that out and don't have to rewire the whole mess. Allegedly the newest, greatest, surge & spike free version of the unit. Worked OK for 1/2 a year, then started the same crap all over. Only cooked one battery this time.

Did not change the unit, it seems to be behaving for the most part at that point, but it has really quirky behavior. Seems to work just fine to stay plugged into 110v to keep the batteries charged for standby. During use when we are camping it sometimes does all sorts of strange things. Some days it works fine under any load. Other days if we are only running a few lights it will just let the battery drain until the lights are dim and the fridge shuts off from low voltage then we have to turn on all the lights to get it to start charging, but if we are using more power from the get go it will work just fine. Other days if we are using more lights it will jump back and forth between "normal" and overcharging, as the lights keep going from normal to way too bright and back. But most days it is good.

That is on shore power. If we use a generator, all bets are off and it does all sorts of weirdness, and some days it is tricky to get it to charge the batteries at all.

Any help out there on this similar problem?

[Dragonslayer140]

Hot Rod, I had the same magnetec converter in my class C, it was loud, produced a horrible quality of output that you would not want to run any electronic devices on. It ended up cooking my batteries and burning out half my light bulbs one night when the rectifier failed. I did quite a bit of research as i did not want to rewire and remodel any more then needed. I came across this Intelli-power unit. RV Power Converter/Chargers, it is a simple replacement for the lower half of the magnetek unit and allows you to retain the original housing, fuse section and breakers. All you have to do is remove the lower charging section and install the new unit. There is a little bit of wiring, but very easy. The following web site has good pictures and description of what is involves. Converting the MagneTek 6325 Charger/Converter to the.

i recommend the add on charge wizard accessory, it plugs into the Intelli-Power , then mounts on the wall somewhere, it gives you a visual of what mode the unit is in, and a button to allow you to select a higher charge rate. The unit will allow "boost mode" for a while, then will drop back to an on demand charge, and once 90 percent is reached it goes to a lower voltage to prevent boiling the batteries dry, every so often it will go into a desulfation mode. I have had this on my coach for around 5 years, and leave it plugged into shore power when ever i am not on the road, has kept my coach and engine batteries at 100 percent, and never had an issue. an other benefit is very clean DC power, never worry about my computers and other elec equipment.

Dave

[hot rod]

Dragon-

Dragon-
Thank you! That is exactly the kind of info I needed. That magna-tec has been making me crazy all year. You are right, it is loud. And the only way I know what it is up to is how bright (or dim as the case may be) my lights are at any given time. Needs to be in a scrap pile.

You used the 4600 series? Looks like the same wiring job as when I "upgraded" to the 7345RU unit the last time, no big deal. They show that model as having the charge wizard built in, is your unit that way, and does it have some sort of indicator light like they show on plug in charge wizard for the 9100 series units?

You are pre-lowering my blood pressure for next trip!

[Dragonslayer140]

Its been a few years, but I believe it was the 9200 series, think it was 45 amps. The magnetek unit was open to the floor under my sofa after i removed the bottom "sleeve" containing the old transformer, fan and rectifier unit, I just slid the new unit in, and connected the wires, in my case the color coding was different in the fuse section, but did not take long to figure out what was what with a meter. I screwed the new unit to the floor and the old cover fit back on. The charge wizard had about a 4' cord with a connector that plugs into the new charging unit, then i ran the wire up behind the couch and used double sided tape to secure it to the end of my kitchen counter. Now at a glance i can see what mode its in, or switch it to boost mode to recharge the batteries if I am dry camping with the generator, will usually charge both deep cycle house batteries in a couple of hours. I purchased mine on sale from Camping World, think it was about 150 with the wizard. best money i have spent on that rig.. twice that might fill my gas tank now lol. I have to thank the person who put together that installation web page, I came across that years ago when i was having problems with the original unit.

Dave

[hot rod]

OK, that makes more sense with your explanation and reading through the instruction website. The 9200 unit you and the article used are more of a stand alone unit and are sort of "rigged" in there as to the mounting to fit into the Parallax case. The 4600 is designed as a direct fit slide in unit just like the original Parallax mounting, even comes with a new mounting sleeve. I would assume the same internals, but I will check with the company on that before I order.

Thanks again for the info.

[hpcrank]

Wow, guess we are not the only rig with battery issues. Thank you all for the input.