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Topic: House Battery Replacement in a Roadtrek Versatile

Posted By: VE3ESN on 06/17/04 07:51am

Our 1996 Roadtrek Versatile (Dodge) uses a metal box under the floor at the rear driver's side of the vehicle. Because of its location, it's somewhat inconvenient to use a battery that requires maintenance, i.e. filling up with distilled water, checking specific gravity, etc. That's probably why Roadtrek installed a sealed gel battery in the original vehicle, although ours had been replaced by the previous owner with a so-called marine/RV battery, also a sealed type. That battery has finally given up the ghost, so this time I bought an Optima D34/78 yellow-top true deep-cycle battery using the newer AGM technology (absorbed glass mat). I was pleased that our local Costco sells this battery, although it's not cheap ($218 Canadian). The battery is a bit smaller than the type 24 it replaced, fits well in the compartment, and is a sealed, non-maintenance type. I hope to get much more use from this battery than the previous one.

One thing I learned is that when you're camping at a site with shore power, you should flick OFF the "battery" switch on the control panel (where the tank levels are indicated). As many of you know, the Magnetek 6300 series converter supplied with the Roadtrek and other RV's isn't a particularly good battery charger, because its output voltage is too low. The battery will charge adequately when you drive to your next destination. Flicking the battery switch to off when you're connected to shore power can be somewhat confusing, as the red LED stays on. However, I did some measurements and determined that the battery was indeed removed from the converter output in this situation, and that all 12 V appliances (lights, Fantastic Fan, etc.) receive their voltage from the output of the converter.

One little quirk that I noticed is that the propane detector gives an occasional short beep, probably because the 12 V output of the converter contains some AC ripple. I'm going to try some "brute-force" filtering with a high-value electrolytic capacitor on the propane detector output.

Has anyone upgraded their old Magnetek 6300 converter with the version that has a better battery charger? Is it worthwhile if the old 6300 still works, even though it's old technology?

Jerry & Susie
1996 Roadtrek 190 Versatile (Dodge 5.2 L)
FMCA F390585
Trees are being destroyed through the transportation of invasive insects and diseases in firewood. For more information, please visit

Posted By: My Roadtrek on 06/17/04 11:58am

Be careful of your charging voltage.

"AGM and Gelled batteries require a charging voltage that does not exceed 14.00 volts (summer temperatures may require even lower voltages). Unfortunately almost all automotive charging systems have a permanently fixed set point voltage that exceeds 14.00 and this spells trouble. Subjecting the batteries to (commonly found) 14.6 volts for a prolonged period will eventually destroy them. Pusher diesel motorhomes normally use truck-type alternators and voltage regulators and most have internal set screws which can be fine-tuned (To lower the voltage set point). Automobiles (pickup trucks) and standard motorhome charging systems can be modified to accept an exterior adjustable voltage regulator. Your local automotive electrical rebuild shop can be a lifesaver if you elect to go that route. For your edification, 14.05 volts is my personal "upper limit" for charging valve regulated batteries".

More on batteries at my web site. Go to Article/Electrical/Batteries

Posted By: VE3ESN on 06/17/04 04:12pm

Thanks Rodger for the information. From the Optima website, they have a PDF file that lists the specs for the battery. In the section called recommended charging information, they say that the output voltage from the vehicle's alternator can vary from 13.8 V to 15.0 V. I measured the voltage across the new house battery with the engine running, and it measured 14.12 V. It appears that the charging voltage for the Otima AGM batteries has a wider range than some other AGM batteries. What do you or any other forum posters think about these latest comments and my original post?

Posted By: GizmosMom on 06/17/04 05:34pm

I'll be honest and tell you that I am having trouble understanding this thread. So I will just ask one question and see if we can come to a concensus:

When hooked up to shore power at a campsite, should we turn off the
battery switch? In our 2000 Xplorer it is located under the front passenger seat facing the back of the van.

(Now, maybe you already answered that above but I read it twice and couldn't figure it out[emoticon])


Marilyn w/ Joe, 2016 Class C Sunseeker 2430 SF, often pulling a Ranger bass boat.
Smudge, (in photo) a Shih Tzu/Yorkie Mix and Gizmo is waiting at the Rainbow Bridge

Posted By: My Roadtrek on 06/17/04 07:30pm


On mine the switch has to be on (in fact there is a big sign by the switch saying so.) prior to being hooked up to shore power, or running the generator. and can not be turned off.

Posted By: My Roadtrek on 06/17/04 11:27pm

Personally if I were to replace my batteries with AGMs I would replace the stock Rt converter with a INTELI-POWER 9100 Series Electronic Power Converter, and add the Charge Wizard. This way there would be no chance of the AGMs being over cooked. Those batteries cost too much to charge them with the stock Rt converter.

* This post was edited 06/18/04 10:28am by an administrator/moderator *

Posted By: VE3ESN on 06/18/04 07:11am

Rodger, your link to Progressive Dynamics didn't work for me, so here's another: Progressive Dynamics. This is an interesting website with lots of information, but they appear to concentrate on conventional flooded cell (lead-acid) batteries. Their Charge Wizard appears to have extra bells and whistles that aren't appropriate/necessary for AGM batteries.

Marilyn, I don't know what kind of converter/charger you have in your van. Our Roadtrek has the Magnetek (now called Parallax) 6332A unit which is an OK converter but rather poor battery charger. According to The 12 volt Side of Life (Part 1), "......since most converters do not exceed a voltage of about 13.5 V, it will never fully charge your batteries. Also, after it has succeeded in partially charging your batteries, it will then commence to boil off electrolyte, as the 'float' voltage is too high (should be about 13.2 V max.)" The bottom line here, for me, is to not rely on the converter/charger to maintain my new expensive Optima AGM battery, so that's why I turn off the battery switch when we're connected to shore power. One caveat, for the techie types, is that the 6332 converter/charger relies on the battery for filtering the pulsating DC for things like the propane detector, etc. These sensitive DC devices don't operate well with anything but pure DC, so that's why I plan to use high-value electroltic capacitors for some brute-force filtering at the places where it's needed, e.g. propane detector. So Marilyn, what will work for me may or may not be appropriate in your situation. I'll let you all know how the extra filtering works out.

Posted By: VE3ESN on 06/18/04 11:00am

Boy, do I ever have egg on my face! Will that be fried, poached, scrambled or hard boiled?? [emoticon]

I obviously made a serious mistake when I did the initial measurements. Merely flicking the battery switch off on the control panel does not disconnect the charger from the battery when you're connected to shore power.

However, my original assessment of the situation is still hopefully correct! Eventually I guess I'll upgrade to the 7300 converter/charger section to replace the old 6332 unit I have (it slides in). Until then, I can turn off the charger with the circuit breaker on the AC distribution panel, and turn it on only when needed. The bottom line for me is to not leave the battery charger on for long periods when we're camping at a serviced site. For example, we spent a week at Hanna Park in Jacksonville in March, and the charger must have boiled the old marine/RV house battery dry. I don't want that to happen with the new AGM battery!!

* This post was edited 06/18/04 11:26am by VE3ESN *

Posted By: My Roadtrek on 06/18/04 11:13am

The link works now.
AGMs are more sensitive to charging than other types of batteries. Thats why the Intelli-power converter with the charge wizard is so good. If you blow a seal by over charging an AGM battery all you have left is a big expensive paper weight. I must be reading different information about these batteries than you are. I'm replacing my converter, in fact I have already ordered a 9155 Series INTELI-POWER converter (reconditioned from their web site) with the Charge Wizard.
I think it's smart of you to turn off the battery switch when on shore power, otherwise you might be overcharging your battery. I don't have that option, so its the new converter/Charge Wizard for me.
I think PW, and many others come with the Intelli-converter 9100 series, so to add a Charge Wizard all that has to be done is plug it into the converter. Changing the converter is not hard, and here is a web site that makes it easier. Look in Ricks stuff.

Posted By: Handbasket on 06/18/04 12:25pm


When hooked up to shore power at a campsite, should we turn off the
battery switch? In our 2000 Xplorer it is located under the front passenger seat facing the back of the van.

A really simple, direct answer eludes me (as usual [emoticon]).... assuming you've got 'standard' lead-acid house batteries:

When hooking up to shore power at a CG, it's a safe assumption that your batteries are probably ~fully charged from driving. So they probably don't need the extra charge from the on-board charger, and might suffer from it.

But at home, after not driving it or not having it hooked up for a few days, you might want the batteries connected to the charger circuit for a while, especially prior to taking a short drive for a weekend without hookups.

You need to check your owner's manual for the function of the battery switch on your van; they can be wired in different ways, and as this tread illustrates, those aren't always logical, obvious, or straight-forward.

(And all of the above is subject to correçtion by someone who knows more about batteries than me, which wouldn't be hard.... [emoticon])

Jim, "Didja want hash browns or grits with those poached batteries?"

'06 Tiger CX 'C Minus' on a Silverado 2500HD 4x4, 8.1 & Allison (aka 'Loafer's Glory')

Posted By: rarin2go on 06/18/04 03:55pm

Marilyn, I'm confused by this thread also. Is it possible to damage the coach battery by overcharging with the converter/charger while connected to AC power (or the generator)? Our battery switch is called a "12VDC Power Disconnect" and its stated function in the manual is "to shut down all auxilliary battery power". Does the switch also control charging by the alternator, generator, or AC power? Our manual also states that the coach battery "is being charged when the unit is plugged in, the engine is running or when the generator is running". It does not address whether the "battery switch" should be in an on or off position. Our accessories listing indicates that our electrical panel is a Parrallax Model 7345. Is that the same thing as a converter/charger. There is no listing for a converter/charger. Help!! I am in dire need of enlightenment.

Kathy & Bob
'04 LTV Free Spirit 210B
Sprinter Chassis ">

Posted By: My Roadtrek on 06/18/04 04:47pm

Well maybe this will help.

Sustained charging, where the batteries are "floated" at a constant charge (as in the RV converter or with an automatic portable charger) should not be done at more than 13.8 volts (and 13.65 makes batteries last longer). It's supposed to keep the batteries "up" to a reasonable level without undercharging or overcharging them (the assumption being you'll "top them off" by driving). Unfortunately, many cheap chargers and RV converters don't regulate very well. Overcharging destroys batteries quickly. Undercharging destroys batteries too, but more subtly as the battery stratifies and will no longer maintain a charge. In effect, the 100 amp/hour RV battery becomes a 10 amp/hour battery after consistent undercharge. It will read full voltage, but as soon as a small load is placed on it, it drops to nothing. RVers who remain plugged into commercial power for long periods often never know this has happened until they unplug, because the converter's transformer also supplies power directly to the RV circuits while it's charging the battery -- or trying to.
Read more.
And more.

If you are not going to be plugged into shore power for a long period (week or more)you should not have a problem with your batteries. While driving the chassis alternator will keep the batteries charged at the right level.
When I responded to this thread I was talking about AGM batteries which are more sensitive to overcharging, and since they cost twice as much as deep cycle lead acid battery, it might pay to have a converter/charger better than the one Roadtreks comes with.
One more thing, the longer you are hooked up to shore power the more likely the water in your batteries will boil over, so make sure you check the water level, and add only distilled water up to the start of the slot. (Always make sure the plates are covered.)
If you have a smart converter/charger such as the INTELI-POWER Converter, and Charge Wizard you should never have to worry about overcharging, or undercharging.
Here is a link to Harvey's web page that should help you understand the wiring of the Roadtrek, which I'm sure is similar to other CVC's

Posted By: PSW on 06/18/04 08:40pm

My solution to the coach battery problem is simple: I just don't worry about it! I figure that an rv/marine deep cycle battery is good for about one year, sometimes a couple of years. I just go to Walmart, get their's for fifty bucks, use it without much thought and assume it will last a year, maybe two. I do check the water levels every couple of months and I do make sure the connections are clean. I do cut the coach 12v power when I am hooked up to shore power. I don't buy the high dollar gel or other exotic batteries. Just plain old off the shelf deep cycle, biggest one I can get to fit and go on down the road. I have done this for four motorhomes and didn't know I had a problem until I started to read all the battery tech stuff. Ignorance is bliss. And I can boondock a couple of days by being careful on one coach battery without starting the motor or the generator. Works for me. I am probably to dumb to follow all the procedures. Voltage measured in tenths, gassing points, dwell and discharge curves, I just use the blame thing!


Posted By: My Roadtrek on 06/18/04 09:22pm

Actually, my Excides that came with the Rt are still going strong, and I really don't worry about them. I just keep the water level up, and use them. But when they do go I will replace them with AGMs. I like to tinker with the Roadtrek, and I know I will need a better converter for the AGMs. I got a good deal on a refurbished Intelli Converter so I figured I would get it, and go ahead and install it. I hope to get another year out of my batteries. The AGMs are maintenance free, and handle the road vibrations better than other batteries. They also charge a lot faster, and if they are well maintained should last 5 years, or longer. It will be cheaper than buying two $50 batteries each year, and a lot less hassle.

Posted By: VE3ESN on 06/19/04 01:59pm

Thanks Rodger for the information and links. I thought that the only option for the Magnetek/Parallax 6300 was to slide a 7300 upgrade in. But your link to the Intelli-power info has started me thinking that this is the best route. The Charge Wizard option you get with it looks great also. However, I have one nagging question that I can't seem to get an answer for: will the "disulfation" mode of the Charge Wizard have any detrimental effect on the Optima AGM battery that I just installed, since AGM batteries don't seem to require
"disulfation"? Your thoughts?

Posted By: My Roadtrek on 06/19/04 02:53pm

Here is a post I found, but you may still want to check with Progressive Dynamics

RJ -- A few months ago I called the folks at Progressive Dynamics tech support and asked them if the 9100 series converter/chargers were compatible with AGM batteries. The short answer is yes if you utilize the Charge Wizard along with the 9100 unit. The position of their lab is that the voltage requirements for AGM batteries are not significantly different from lead acid batteries. I also found out that PD makes a Charge Wizard specifically for gel batteries because, unlike lead acid and AGM batteries, the charging characteristics of gel bats warrant different parameters in the controller program.

Let me know what you find out.

Posted By: Handbasket on 06/20/04 07:16am

I sorta take PSW's attitude, but I hope to get more than a year out of my two cheap lead-acids. We'll see....

Jim, "I just do what my Rice Crispies tell me to."

Posted By: VE3ESN on 08/24/04 06:01pm

I thought I'd bump this thread up with a short update regarding our house battery. First of all, IMHO, the Optima 34/78 AGM battery that I initially "raved" about didn't have enough capacity, being only 55 Ampere-hours. On a 3-day dry-camping trip with only minimal useage (pump, lights, a bit of TV), the battery went flat, and I do mean flat, after about a day and a half. (It was so flat that there wasn't even enough energy to ignite the hot water heater!) [emoticon] So, for the first time with our Roadtrek, I had to run the engine occasionally just to get a bit of energy back in the Optima. I took the Optima back to Costco for a full refund, and bought a MUCH cheaper ($62.00 Canadian)lead-acid marine/RV battery at Costco (model 24DC made by Johnson Controls) that is maintenance-free and, believe it or not, is rated at 95 Ah. (I don't know the current for this Ah rating). In any event, we just returned from a two-day dry camping trip, and used the battery much more than with the Optima. I was very impressed! The status indicator never went below 3 LED's, and all equipment performed flawlessly. I hope to get long life from this battery now that I have the more sophisticated Progressive Dynamics converter/charger with the Charge Wizard.

Posted By: thataway on 08/24/04 06:54pm

Roger, with all due respect, you are giving information which I beg to differ with. True the gel cell does not allow bulk charge voltages greater than 14.0 volts. However AGM batteries do fine with bulk charge of 14.4 volts--in that is the voltage on the Xantex 3 stage chargers. I checked this on the Lifeline, Johnson Control and Corcordia AGM battery sites. I don't know where the rumor that AGM require a lower voltage started, but I suspect that this is a hold over from the gel cell days.


Bob Austin--been using AGM's on boat and RV's for about 5 years.

Bob and Marie Austin
Angel miniature poodle
2007 Holiday Rambler Ambassador 40 PDQ
Toad 2012 GM Yukon XL 4 x 4

Posted By: My Roadtrek on 08/24/04 07:33pm

I was talking about a float charge under 14 volts, not a bulk charge. I can give you multiple links to back this up if you want. So before you accuse someone of giving misleading information, get your facts straight.
AGM (Absorbed Glass Mat) batteries: A dense fiber matting between the plates and a liquid electrolyte provide
similar features to gel batteries but are much more rugged since they were designed for use in aircraft and rough terrain vehicles. The best AGMs are those made by "Concorde" (usually under the "Lifeline" label but Concorde will appear somewhere). AGMs (like gels) are very sensitive to overcharge. 14.38 volts is recommended for the initial (bulk) charge and 13.38 as a "float" charge.

On edit, maybe I didn't make it clear that I was talking about a float charge instead of a bulk charge. If this is the case disregard the "get your facts straight" comment.

* This post was last edited 08/24/04 07:53pm by an administrator/moderator *

Posted By: thataway on 08/25/04 12:31pm

Thank you for the reply. My appologies if I offended you. My post was prompted by your post:

"Be careful of your charging voltage.

"AGM and Gelled batteries require a charging voltage that does not exceed 14.00 volts (summer temperatures may require even lower voltages)."

I certainly agree that the float voltage for AMG should be in the mid 13 volt range. There seems to be confusion in the RV world that Gel and AGM batteries have similar characteristics. One feature of the AGM is that it will take a higher and more rapid charge than a flooded lead acid or especially a gel cell. Over 14 volts will ruin a Gel cell very quickly. I use boating chargers and regulators on my RV's because they use three and four stage chargers and regulators. These allow the owner to specifically set the acceptance, Bulk and float charge--as well as equalize where appropiate. I also use pulse technechology to preseve batteries (Battery Minder). We are beginning to realize in the RV industry that there are much better ways of handling battery charging other than the old fashioned converter (with a minmal poorly regulated charger) and an automotive regulator. The better battery management is important for those of us who do not plug in to 110 volt power every night.


Posted By: Jim&Carolyn on 08/25/04 01:16pm

You folks may have answered a question for me. About a month ago, I replaced my Interstate wet cell battery with an Odyssey PC 1700 dry cell battery. Twice now one of the circuit breaker blocks have tripped and I haven't been able to figure out why. But, maybe I'm overcharging the battery and tripping the circuit while driving? I've only noticed this happening after driving for a few hours. Can the battery be too powerful for my rig? Any suggestions would be appreciated.

Jim Tewell
2015 Arctic Fox 811
2015 GMC Sierra Denali, 3500, Crew Cab, Standard Bed, 4WD

Posted By: My Roadtrek on 08/25/04 02:37pm

[quote]Roger, Thank you for the reply. My apologies if I offended you. My post was prompted by your post: "Be careful of your charging voltage. That one post I should have make it clear that I was talking about the "float" charge. I did make that reference in a couple of posts later in the thread. I don't get offended all that easily, I have been wrong too many times. I think it was the misspelling of my name that did it. :B

Note: Due to invalid formatting, all formatting has been ignored.

Posted By: VE3ESN on 08/25/04 05:42pm

Since clarification seems to be the order of the day, my last post refers to my poor experience with the Optimum AGM Battery, not AGM batteries in general, as I have no experience with Lifeline batteries, for example. My further research about the Optimum AGM batteries indicates that they are excellent for automotive applications involving heavy loads such as the monster stereo systems that some people (mainly teenagers) seem to enjoy. Even though they are ostensibly deep-cycle, they aren't in the same category as Lifeline or other AGM's. Not wanting to spend the big bucks for an AGM battery more suitable for an RV, like Lifeline, I opted for the simpler flooded cell battery I mentioned in my last post. I know that the Progressive Dynamics converter/charger and the Charge Wizard that I recently installed is essentially designed for this type of battery, although it appears that it would be fine for the AGM type as well. In my case, $62 for a rating of 95 Ah (printed on the side of the battery) versus $228 for the Optimum with its rating of 55 Ah caused me to rethink my original decision to go with the Optimum. Even though this new battery from Costco is the compromise marine/RV type, I'm hoping to get more life from it, because I'll be certain that leaving the PD unit with the Charge Wizard always connected at home and when camping at a site with electricity won't boil the battery dry as happened with the old Magnetek unit I replaced.

Posted By: thataway on 08/25/04 07:40pm

In answer to Jim Tewell's question about a new Odyssey PC 1700 battery being overcharged and the cause of tripping a circuit breaker: Looking at the web site, the Odessy PC 1700 is rated at 142 min reserve capacity (the number of minutes a new, fully-charged battery at 80ºF can be discharged at 25 amps and maintain a voltage equal to or higher 10.5 volts for a 12-volt battery). This is a high residual capacity and gives more "power" for running 12 volt accessories on the coach than most comperable phyical size batteries.
This should not cause coach breakers to trip. In fact it should be the opposite--when voltage drops on draw from the battery, the amperage goes up. With a larger battery, the voltage will stay higher. (Ohms law Voltage = current x resistance) From the Odyssey web site the minimum charging voltage is given at 14.4 volts and the maximum charging voltage is 14.7 volt. You might want to check the voltage when the engine is at speed--measured at the battery. An isolator, rather than a combiner, will often give half a volt drop from the charging source. A caution is given not to hook up to a high capacity charger for more than 24 hours. As Rodger (a second appology for mis-spelling his name) notes once the battery is charged the regulator should go to float mode--and this should be in the mid 13 volts. One of the problems of automotive type of regulators is that the typical car is driven a few miles and the alternator has to make up for the start, running airconidtioning units (magnetic clutch and fans) or lights etc--so that the charge rate/voltage is set higher than is ideal for long distance running, where the battery may well be fully charged in an hour or so of driving.

Rodger I reviewed all of the links on your web site this PM--thank you.

Posted By: My Roadtrek on 08/25/04 09:25pm


I agree with Bob, I don,t think it's a battery charging problem, it sounds more like a short somewhere. If it happens while you are driving maybe the vibration is causing a wire to short out. I would recheck all your battery connections.
Good luck.

Posted By: Jim&Carolyn on 08/26/04 08:08am

Thanks Bob & Rodger for your replies. Can you see I'm grasping at straws here? Since I installed the battery, a loose connection is possible. I'll take it to my local mechanic and have him test out both the connections and the voltage for me.

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