81 Excella 280 battery charging switch position

[silverback]

Our coach batteries our drained. May be cooked by original converter and AZ summer heat or... the charge/store switch was in the wrong position. Please take a look at 1st photo of switch and let me know. I also found the 30 amp in-line fuse (see 2nd photo lower right corner next to red wire splice) open. That can't be good. Either the switch and or the fuse is probably contributing to the battery condition. Or they just got fried... The good news is the engine battery is fully charged (if not high at 14 DCV +) and the engine starts instantly. All help appreciated. I would love to get more life out these batteries.
Thanks,
Ken

[ScrapIrony-2]

Ken,
We had to replace both 29 series AGMs this year...part of the problem was a wear-through on the + battery cable leading to the solenoid...another was leaving the thermostat on the rear heater at 55 in an environment that is routinely below 40 at night...a small solar panel for recharging might help, but it sounds like a drain, somewhere...I now carry a voltmeter in the battery tray...I know your batteries are not in a slide-out, but the juice is going somewhere...mike

[silverback]

Mike,
The battery drain and blown fuse condition occurred while the coach was plugged into shore power. I guess there still could be a short somewhere but I suspect the old converter fried them or I have the switch in the wrong position. I don't want to replace the batteries until I have a replacement converter (inverter and solar installed too) if I can help it. Which brings up another question. How do I get under the bed to access the converter? Do I have to take it apart or is there a trick to lifting the bed up?
Thanks,
Ken

[ScrapIrony-2]

Ken,
We have twin beds in the rear, and the converter is under the kitchen cabinet...not conversant enough with your set-up to give any useful advice...unless a floor jack and sledgehammer might help... ...someone out there will be able to give better direction...m

[silverback]

Hey Mike,
Do you remember where you purchased your series 29 battery replacements? I'm not actually certain what series is in our 280 but I have to do that (replacement) this weekend. We're south of metro Phoenix East Valley. And I still need to figure out how to access the converter AKA "cooker" without major bed renovation.
Thanks,
Ken

[ScrapIrony-2]

Ken,
We bought our batteries at Discount Solar in Q-town...have you considered solar? Our first set fried because we have a pull-out drawer for the batteries, and the wire rubbed against the PO's addition of a splash shield below the solenoids(on ours, it's behind the steps)...SHOCKING!!! 5 layers of duct tape later and the batteries are holding their own. Yeah,, cheap fix, but I also bent the 'shield' back out of the way.
Do you have switches inside the coach that allow you to shut off the chassis and coach batteries? Ours shorted out, and that's what fried our solenoids...that was, of course, 850miles BEFORE the batteries dumped on us...if yer gonna throw money at one of these, throw some at solar, with a charger 'Y' to the chassis battery...the Blue Sky controller 2000E has served us quite well...the system has paid for itself in the 3 years since we bought it...The folks in Q at Discount Solar are knowledgeable, are not hard sell, and talk to you...at least they were when we had the solar panels installed.
6-volt is a way to go, but if one goes, both go, and I'm not really sure that a 280 has room for 4 6-volt batteries...hope this helps, some, at least...mike

[silverback]

Thanks Mike,
I'm pretty sure we have two series 27 coach batteries. And wonder of wonders they actually still seem to be holding a charge. I guess replacing that 30 amp fuse helped. The little round indicator window on the batteries is no longer green (I guess it is blank or black) but the DVM showed 13 VDC on all batteries and the diesel fired right up yesterday. Our main is issue is still trying to figure out how to get to the Uni-volt under the bed for replacement. I don't want to put any new batteries in the coach without replacing that too. Solar is going to have to wait a couple months longer.
-Ken

[silverback]

We limped along for quite a while but no longer. Can't get the Excella started and the "engine" battery (not the coach batteries) appears dead. I'm resisting replacing just the battery. I want to replace the Univolt (somewhere under the bed) with a converter/inverter that will handle solar and not cook batteries before I replace the engine battery. So any recommendations?
Thanks,
Ken

[dadstoy]

Originally Posted by silverback

We limped along for quite a while but no longer. Can't get the Excella started and the "engine" battery (not the coach batteries) appears dead. I'm resisting replacing just the battery. I want to replace the Univolt (somewhere under the bed) with a converter/inverter that will handle solar and not cook batteries before I replace the engine battery. So any recommendations?
Thanks,
Ken

Ken,

Typically, for a stock/factory setup, the 120v to 12v converter (the Univolt in your case) does not charge the engine battery. The house and engine batteries are not "hooked" together on that side of the system. This is so one battery is not drained by the other as they will try to equalize each other. So plugged I to shore power will not charge your engine battery. Running your generator will in most setups charge both house and engine batteries. The house batteries will get charged via the converter and the engine battery directly by the generator since the engine battery should be the starting battery for the generator as well.

What charges the engine battery is your engine's alternator. The alternator in a stock configuration is connected to a battery isolator mounted up front on the firewall. The isolator will charge both the house batteries and the engine battery. The isolator isolates the house batteries from the engine batteries so the one doesn't discharge the other.

If your engine battery is not charging, then the first step is to check the output of your alternator. Then check to see that the isolator is working correctly. Last year I replaced my burned out alternator with a 200 AMP alternator. The stock alternators put out too little amperage and if all your 12v electrical systems draw more then what the alternator puts out, the alternator will burn out in short order. If replacing the alternator with a high output unit, you must also replace the isolator with a high amperage unit.

When I am plugged into shore power and not traveling (running the engine for day or weeks) I have a small three stage charger that I plug into 120v and directly hook up to the engine battery to charge the engine battery, again because the converter does not charge it.

When you get your engine battery charging problem squared away, then yes, I would definitely replace that old Univolt. They're single stage chargers and they will over charge and boil your batteries. I installed an Inteli-Power 60 amp converter last year. In my '81 280, the converter is located under the right side rear bed. It sits between the wheel well and the generator box. My bed lifts up and I can get direct access to it. My 12v fuse panel was located there as well. Check it over too. The original one shorted and fried itself one night a couple years back and I replaced it with an inexpensive aftermarket unit.

Check out my "Dad's Toy" thread for pics.

[345bill]

If you decide to change your old converter call Randy at: www.bestconverter.com

He was a big help when I purchased a XADC 60A Converter/Charger and a XADC 30A AC/DC Dist Panel from him two years ago for our 1990 345LE. Since that time the only thing I've had to do with my batteries is check the water level once in a while.(knock on wood) I had constant battery problems with the factory, univolt?, converter before that.

[silverback]

We replaced the starting battery and it fired up first kick (including 10 seconds or so on the glow plug button). Getting the old Diehard Gold group 65 out of the tray took longer than driving back and forth to Batteries Plus and installing the new Optima yellow top. It was a two person job to loosen all the battery hold down hardware and get that removed first. If only my arms were a foot longer... Now I have to put all that back. I think the PO must have fabricated some of those brackets. I can't believe the factory would ship that kluge. Glad it wasn't the alternator. Next up is the converter.

[idroba]

Silverback: I sold you that motorhome for Burt... grin.. Idaho.. .remember? Was Burt's, but I still know a lot about it, having traveled a lot with them.

When Burt got that motorhome, the original owner to him had cobbled up the battery tray system and Burt got a new one from the factory, so although it may seem strange, it is just like it was originally from the factory. Burt hated the battery system. Now, the switch under the dash was one he added, along with an extra furnace battery which I can explain best in person.

I am wintering in Phoenix area now, San Tan Valley. Private message me and we can make arrangements to get together, and I can tell you more about what you have. Would be glad to come over and see the rig, and give you a hand.

And yes the converter/charger univolt is very difficult to get at, another factory deal.

Let me know, I am sure I can help you out best in person.

Or you can call me at: two 0 eight eight one six three nine 0 one.