As an electrically illiterate Barthmobiler, I need some more advice.....

Unsatisfied with the way my 28 year old, dual output converter maintained the flooded cell 105a house battery, I've purchased an IntelliPower 9245 converter w/ integral Charge Wizard....going in this weekend.

My wiring is standard format for a 70's-80's era coach, i.e.: electronic isolator between chassis & house batteries, with a momentary switch & relay to tie them together.

As I understand it, while on shore/generator power, the converter will NOT be charging the chassis battery - only the house battery. Is this correct?

I'm asking because the chassis battery is a sealed unit. With the new Charge Wizard, I'll get a 14.4v equalization shot every 21 hours or so, and I'm not sure that the subsequent gassing off would a good thing for a sealed battery - no way to replace vented water......

So, is this much ado about nothing, or should I have a concern? All comments solicited, unless you're gonna tell me I bought the wrong converter

Incidently, if you're converter shopping, look around....CW wanted $214 for my converter...an E-bay store had it for $127, new in the box w/ full warranty.....

If yours is wired like mine, which is pretty standard, the only way charging current can get from the house system to the start battery is if the aux start relay is closed.

The isolator keeps any charging current from going to the start battery through it at all times, and the aux start relay just bypasses it to help you start if the coach batteries are higher than a weak start battery.

You can verify this by letting your new converter charge the house batteries while you observe the voltage on the start battery with a digital volt meter. If you make up a cigarette lighter plug with trailing leads, you can use the dash lighter for this. If you install a lighter socket connected to the house batteries, you can monitor either system easily.

By "sealed unit" do you mean your chassis battery is a gel cell?

In any event, the Charge Wizard will have no effect on it, as the Intellitec will charge only the house batteries.

Not that you MAY have to run a jumper on the 12VDC power panel since the dual output has a separate lead fro the batteries (and a separate charge circuit...when connected to 120VAC, the dual output supplies the 12VDC circuits in the coach with one circuit, while the charger circuit separately charged the batteries.

When 120VAC was disconnected, a relay closed to connect the batteries back onto the 12VDC house circuits. That's where you may have to put the jumper...across those two outputs. #8 or #6 (or even #4) wire recommended...

Thanks for the input & suggestions gentlemen....

The chassis battery is just a flooded cell, "maintenance-free" type - not gelcell.

Rusty's advice will be more understandable to me after the new converter is out of the box, instructions studied and the old converter exposed for removal......Back in January, 1978, Barth must have thought the OEM converter would last forever, 'cause they mounted it in the back corner and then proceeded to build the clothes closet over it and around it.....Gonna have to pull carpet and cut a trap door in the closet floor to access the converter. (They did install a cooling vent, but even I know that a 6x6 converter ain't coming out through a 3x8 vent hole

quote:

Originally posted by Lee:
...they mounted it in the back corner and then proceeded to build the clothes closet over it and around it...

They did that to mine too, but they allowed the closet to have a false bottom. The floor is tight in it's base, all I did was pry up on it and it popped off. There were no screws or nails holding it down.

Bill N.Y.

....And THAT'S why you make the big bucks, Bill....Thanks - I'll check it out.

Actually, I would have noticed that on my own, right AFTER I finished cutting a trap door in the floor!......

FWIW, mine has a vented door that allows access to the gen/pole power switch, fuses and circuit breakers, in addition to the false bottom of the closet above it.

Lee, this, and to some extent, this may help.

Good Stuff! Thanks Rusty.......I'm still working on the high-tech part, i.e.: getting the $#@& closet floor to pop out....I should be able to ask more intelligent questions when that's done and I can see what I've got.........

If I luck-out and don't start a fire with the converter swap-out, Phase II involves installing a 1000w stand-alone mod-sine inverter, feeding one dedicated & isolated recept. for an 800w coffee maker or used for tv/dvd/cd player/computer feed. (unless there's a better way?.....)

This discussion reminds me that I also need to replace the converter in our '72 Barth.According to the paperwork it's a Progressive Dynamics that was purchased/installed in 1978. It seems to work well enough but produces an objectionable humming noise so long as it is on. I sometimes use the Barth as a 'quiet zone' when things are hectic, and I want/need silence therein if nothing is running other than the converter-so replacement seems optimal.
Would one of you experts recommend an appropriate replacement for me to obtain?
we appreciate the help.
thanks,
geoffrey

I replaced the original in my SOB with the Intellitec 9160, mainly because the old unit only had a 15A charging circuit. With the Intellitec, the charger is 60A, and is a single-output, meaning that when running 120VAC, the charger charges the battery, and 12VDC circuits power from the battery, not the converter itself.

Just about any converter will have a thermally-activated cooling fan which will turn on periodically. That may be less intrusive than the hum, but you need to be aware of the issue.

The hum you hear is probably coming from loose windings in the step-down transformer (120VAC to 12VDC).

If that's the only complaint, you can probably fix that by taking the cover off and dousing the transformer coils (you may have to unmount the converter chassis to get the transformer vertical) with thin cyanoacrylate glue (a/k/a, "Super Glue", but that's a brand name unsuitable - it's too thick). Hobby shops will carry the very thin stuff; Goldberg and Pace are two common brands. Have some acetone handy to clean your hands, as this stuff is great for sticking fingers together - it's used as sutures for some incisions...

The traditional coating for transformer laminations is glyptol. It seemed to take the combination of age and heat a little better than the cyanos we had. Both electronics shops and hot rod shops sell it. Engine builders use it to coat the inside of engine blocks.

It is also possible that just a little tightening up of hardware will cut down on the hum. Even forcing silicone rubber into suspect joints can help.

My original converter just had a standard plug in to a standard wall outlet right next to it, so you could unplug it when you want quiet time. Or flip the circuit breaker off.

Our Barth is better insulated than previous RVs, which is great. However, the pitter patter of rain on the roof is almost unnoticable.
One of our jokester friends threw birdseed on the roof so birds would gandy dance early in the morning and wake us up. He was quite disappointed to learn that we heard nothing.

Update: Thanks to this thread, my converter swap-out was painless! After running my fingers through the closet floor carpet, I found a plywood seam in the middle...also a finger hole in the plywood near the vent pipe. The floor simply lifted out in 2 pieces and exposed the whole area. It was also a good opportunity to install some sound-deadening sheets on top and around the generator box - it did make a difference.....

Out came the bread-box size, 50lb, circa 1978 converter and in went the cigarbox size, 5lb Intelipower 9245 with Charge Wizard. Also treated myself to a new Group 27 Trojan wet cell deep cycle battery...at 105 amps (20 hr), it should be more than enough for a couple of nights in a short coach.

Because I've stayed plugged-in at home & on recent trips, I didn't realize my old house battery had a dead cell....probably got cooked-off by constant charging from the old single stage converter. (I gotta pay attention to those things!) I should have gotten suspicious when I had to bring the engine battery online to start the generator........

On another recent thread, I lamented about the genny running for 10-15 minutes, then starting to stumble and finally die, loaded or unloaded.
Plugs/points/capacitor/wires/coil swap-outs didn't solve it - neither did fuel system clean-up, carb cleaning & adjusting, etc.

In retrospect, I now wonder if the bad house battery was the culprit.....Could it be that I had enough juice to keep the jenny running for a little bit until the old "5-cell" battery ran out? (If the battery was given a rest for an hour or so, I could repeat the process, albeit a shorter running time before stumbling.....)

I'm headed out for a 700 mile trip this weekend so I'm sure I'll find out, but maybe someone can can confirm that this bad house battery may have been the factor in erratic genny behavior all along..........

As always, Thanks to the group for the help.... Without the benefit of this site's Brain Trust, I'd probably be paying someone $80-$100/hr to accomplish these projects......

quote:

Originally posted by Lee:
Back in January, 1978, Barth must have thought the OEM converter would last forever,.....Gonna have to pull carpet and cut a trap door in the closet floor...

I'm glad yours was like mine. I have worked on some units that they built the entire rig/coach/truck around the item I'm trying to service. The engineers should be made to take apart whatever they build.

quote:

Originally posted by Lee:
As an electrically illiterate Barthmobiler, I need some more advice.....

With electrical it's the fear factor that stops most people. There's really nothing magical about it. Now you can teach someone else. A little respect and a willingness to ask and learn. It's the people who think they know what there doing that scares me!

Bill N.Y.

quote:

Originally posted by Bill N.Y.:
The engineers should be made to take apart whatever they build. Bill N.Y.

LOL. That is almost a mantra in airline maintenance.