Well, I done a dumb thing....

[IdahoRenegade]

I parked my '01 Roadtrek in the garage last fall after winterizing it. I've been pretty good about going out and running the generator for an hour once a month or so-seemed to keep the coach battery topped right up. Now...I was under the impression that the chassis was connected to the coach system by a diode or regulator, such that the chassis alternator would charge the coach when the chassis battery was charged (which seems to work), and isolate the chassis battery from discharge from the coach system. I also thought the coach generator would charge the chassis battery when it was running.

It appears that I was wrong. Stuck the key in the ignition and stone-cold dead battery. I'm charging it now, and was able to get the rig to start. Took it for a ride then parked it-I'll see if it's holding charge in a few hours.

So, am I incorrect in thinking that the gen would ever charge the chassis battery? Or is there a switch somewhere I need to engage to do so? Not really a big deal as long as I know-if I'd had a clue I'd have thrown a battery tender on when I parked it. I thought I had read through the forums and had a clue, but obviously not.

Could be worse-battery has an '09 sticker, so was about due for replacement anyway. But with use of a tender over the winter I've had them last a long time.

Thanks.

[markopolo]

Older Roadtreks have an isolator and it does not allow for charging the chassis battery when plugged in or running the generator.
I don't know what year RT started installing battery separators that allow for allow for charging the chassis battery when plugged in or running the generator. The '04 I had an isolator not a separator.

You have a few options:
- jump the isolator terminals (not recommended as too easy to forget to remove)
- a battery tender like you mentioned - I used one that plugged into the 12v accessory outlet on the dash
- install a switch
- upgrade to a battery separator
- run the van engine

and maybe others........

[Mike]

I had a bad diode in my '02 isolator which would allow the coach systems to draw down the chassis battery, if/when the coach batteries were enabled. If that wasn't your case, then read no further.

They were made for Roadtrek by an outfit called Hehr Powerline, and I picked up a replacement when we were in the DFW, TX area a few years back. If your isolator is placed such that you can get a multi-meter on the terminals easily there was an isolator test procedure on their website somewhere, or I may have put a copy of it on here somewhere. If you suspect your isolator my be faulty. Hehr "contact us" support were pretty good at responding to email queries, as I recall, if you have any questions.

Otherwise, Marko's and your suggestions for preserving charge status for your chassis battery when not in regular use, are probably your best options. You might also consider switching your chassis battery from a typical starting type, to a deep cycle type, in the event that it runs down again between recharge cycles. They tend to be more durable in those situations, and may survive more discharge cycles than a starting battery.

[eric1514]

Install one of these

http://www.lslproducts.net/TLSPage.html

This will charge your chassis battery from your coach battery.

[Davydd]

Both of my Bs, the Pleasure-way and Great West Van never charged the chassis battery from being plugged into shore power for the auxiliary battery. I assumed that was the normal setup. Periodic starting during the cold Minnesota winters was all that was needed in my experience.

[Caped Crusader]

You can use the Battery Tender Jr. to keep the chassis battery charged when the coach is plugged into shore power. You can purchase the longer cord, and case from the "accessories" link. Just plug it into a live ac outlet in the coach, and plug the 12 volt end into the cigarette lighter, or accessory receptacle. You may find it cheaper at Amazon, etc.
I also use it (as a trickle charger) on our cars to keep the batteries charged, and healthy when they are going to sit for awhile.

[Mike]

That would work.
Not a bad idea, either, if you're plugged in during shore leave.
Or, get a remote starter/alarm installed, and just start the van every once in a while from the comfort of your living room.

[IdahoRenegade]

Thanks for the info. I have 2-3 Battery Tender Jrs sitting around or on ATVs and bikes. I could have plugged it in any time. Looks like I dodged a bullet though-it started up after sitting (off charger) overnight. I'll plug it in on 2A charge and leave it a few more hours. I'm bringing the charger along this weekend! Rather than jumpering the "isolate" terminals as mentioned, I'll put a switch there. It can stay "on" over the winter, that way the gen should keep both bats charged, then flip it off during the camping season. (or hope I remember to!). So...just where are these "isolate terminals" located?

[Mike]

Originally Posted by IdahoRenegade

So...just where are these "isolate terminals" located?

On the isolator. On my 2002 it's mounted on a frame cross member under the front of the van, so that was why I suggested testing it, if it's easy to get at. Mine isn't. It will be the size of a small brick and have heat sink on it, as well as 3-4 threaded posts (terminals) with wires and nuts on them. It might also be located in the engine compartment somewhere, which makes it a lot easier to get at, and makes more sense to me, except when it's hot out. It may be red or blue in color. If it's the OEM Roadtrek isolator from back then, it's probably red. After market models (like the replacement I got directly from Hehr Powerline) might be blue, or just about anything. Before and after.....

[peteco]

Mike,
What is the red stuff you sprayed over the terminals?
Pete
2006 RT210P

[Mike]

Hi Pete. It's an electrical sealant spray for insulating exposed terminals and connections. I didn't actually apply it myself, I asked that it be sprayed on when I had the isolator replaced at an RV shop. I couldn't get elbow room under the van, considering where Roadtrek decided to place it on my model year, or I would have done it myself.
It's probably Permatex battery cleaner and sealer, or something similar. Available at fine auto parts stores everywhere?
It actually looks and feels like a gasket sealer/adhesive I used decades ago when I replaced a water pump on a big block Ford V8.
The W/P was easier to get at than the isolator, and I was a tad younger and more DIY adventurous.

[IdahoRenegade]

Originally Posted by Mike

On the isolator. On my 2002 it's mounted on a frame cross member under the front of the van, so that was why I suggested testing it, if it's easy to get at. Mine isn't. It will be the size of a small brick and have heat sink on it, as well as 3-4 threaded posts (terminals) with wires and nuts on them. It might also be located in the engine compartment somewhere, which makes it a lot easier to get at, and makes more sense to me, except when it's hot out. It may be red or blue in color. If it's the OEM Roadtrek isolator from back then, it's probably red. After market models (like the replacement I got directly from Hehr Powerline) might be blue, or just about anything. Before and after.....

Hey, thanks for taking the time not just to answer, but to post the pics. I appreciate it. I'll dig out the manual and figure out which set of terminals have to be jumped.

[IdahoRenegade]

Originally Posted by Mike

On the isolator. On my 2002 it's mounted on a frame cross member under the front of the van, so that was why I suggested testing it, if it's easy to get at. Mine isn't. It will be the size of a small brick and have heat sink on it, as well as 3-4 threaded posts (terminals) with wires and nuts on them. It might also be located in the engine compartment somewhere, which makes it a lot easier to get at, and makes more sense to me, except when it's hot out. It may be red or blue in color. If it's the OEM Roadtrek isolator from back then, it's probably red. After market models (like the replacement I got directly from Hehr Powerline) might be blue, or just about anything. Before and after.....

Hey, thanks for taking the time not just to answer, but to post the pics. I appreciate it. I'll dig out the manual and figure out which set of terminals have to be jumped.

[Mike]

No problem. I occasionally have more than theoretical experience, good or bad, with some of this stuff.
While the idea of jumping the terminals or adding a 2 way switch to reverse current flow when needed, those options may be more dangerous than they're worth, particularly at the typical voltages and amperages under there.
Depending on the placement of your coach batteries, and their distance from the chassis battery, it might be easier to get a long set of jumper cables and use if required in an emergency starting situation. I usually carry a long set myself, jic. It's a simple solution, and that always works for me.
For charging the chassis battery, Caped Crusader's idea would be my choice.

[Caped Crusader]

These are a pieces you need to use the Battery Tender Jr to charge the chassis battery. Amazon has them under Battery Tender Jr.
$12 to $15 plus shipping. Plug the BT Jr into 110 inside the coach area, and the cig extension adapter into a cigarette receptacle on the dash.
Battery Tender Deltran Cigarette Lighter Adapter 081-0069-5 by Deltran
Battery Tender 081-0148-25 25' Quick Disconnect Extension Cable

[markopolo]

A battery tender works if you keep the rig plugged in but won't help much if only using it combined with monthly generator exercising as you wouldn't get much out of it in the short time running the genset.

With a 2001 you should check the converter output to make sure it's low enough to work as a float voltage if considering leaving your van plugged in all winter.

The easiest to do would be to run the van engine for maybe 1/2 hr when you exercise the generator in the winter. You can run them at the same time. I used to exercise my Onan when driving because I didn't like running it at home. The RV was close to neighbors.

Measure the output from the converter (assuming single stage charging) after you think the batteries are fully charged as the output might appear low initially with single volt output converter.

[Mike]

Excellent points, all.
I too am single stage converter/charger challenged.
Markopolo suggests try to remember to run the van and generator as required in the winter. Sage advice.
I had a remote starter/alarm installed and I can run the van for a while every so often during when it's parked. The generator I run as often as the outside temperatures will permit.

[avanti]

I don't know about the genset, but it really is neither necessary nor desirable to run the engine of a stored vehicle. It does no good and can actually do harm. In particular, every time you start the engine, you introduce water vapor into the engine and exhaust. Unless you run it long enough to cook it away, it will condense inside the exhaust system and contribute to corrosion. That is why exhausts rust from the inside out.

Just disconnect the battery ground to remove any parasitic loads (or better yet, install a disconnect switch) and all will be well in the spring. It takes many months for a healthy battery to self-discharge if completely disconnected. Or, use a battery tender as mentioned above. And, if you choose to ignore this advice, make sure you go for a nice long drive, not just an idle in the driveway.