Installing a 4-stage converter/charger in your new Airstream

[Msmoto]

My choice was the PowerMax PM4B-60 from Bestconverter.com called a Boondocker.

The first step is of course, remove all power, battery connections from the trailer.
Next, remove the original converter/charger (C/C). It looks like this when one removes the top to look inside:

CONVERTER-CHARGER_Final Imagesl_10.10.2014-5 by Fantinesvoice.com, on Flickr

On my Serenity 30RB, the fuse panel is held on to the original C/C by two screws, so i removed these and left the fuse panel wired into the trailer circuits. To hold this when the new C/C is installed I fashioned an “L” bracket from 3/16” Lexan, held to the floor by two screws, and this also holds the front door hinge as the original mounting points go with the original C/C.

CONVERTER-CHARGER_Final Imagesl_10.10.2014-3 by Fantinesvoice.com, on Flickr

The new Boondocker is installed in the large space where the original C/C was, moved toward the rear so as to have good ventilation at both ends so the fan can cool it as needed. This is held down with four screws into the floor. The wiring is fairly straight forward, the 120v power cord dissected and the line, common, and ground wires attached to the appropriate wires existing from the removal of original C/C. The 12v lines and chassis ground from the new Boondocker are connected as shown. I used #6AWG for the connections.

CONVERTER-CHARGER_Final Imagesl_10.10.2014-2 by Fantinesvoice.com, on Flickr


Converter_Schematic_For Forum.001 by Fantinesvoice.com, on Flickr

Close up of connections on the Boondocker

CONVERTER-CHARGER_Final Imagesl_10.10.2014-4 by Fantinesvoice.com, on Flickr

After double and triple checking I turned on the shore power and measured the voltage from the Boondocker at 14.66v. I then checked the batteries and they were at 12.6v. After disconnecting the shore power I reconnected the batteries into the circuit and powered up everything from the shore power. Gosh, it all seems to be working. And, of course one replaces the cover for the 120v area, so ti looks like this:
CONVERTER-CHARGER_Final Imagesl_10.10.2014 by Fantinesvoice.com, on Flickr

Any comments or questions are welcome. Easy job if one uses common sense and takes their time.

[RVDreamer]

Msmoto,

Thanks for the installation photos. Looks like a really good job.
You were doing this on your 2015 Serenity which has the 50 Amp service upgrade is that right?

I am thinking I will want to do this with my 2015 27Fb Serenity with 50 Amp upgrade after I pick it up in a few weeks.

[Moo1822]

Nice work! FedEx delivered mine literally an hour ago and now I have your post above as a guide for installation. Thanks for taking the time to document the process...

Now, off to find some 3/16" Lexan...

[Msmoto]

Yes, my Serenity has the 50 Amp, so one must use a 60 Amp, Converter/charger. Before I installed this I spoke with Airstream who confirmed the standard charger would simply apply a full charge to the batteries and not go into a float stage. Thus, it was recommended the water be checked as often as once monthly.

Then I spoke with Randy at BestConverter - Converters, Inverters, Electrical Supplies, Electronics and he gave me the recommendation for the converter. What this does is to charge the batteries, then go to float, and PM4B models now include built-in conditioning cycle to prevent stratification that can lead to battery sulfating.

The installation is about the same whether 30 or 50 Amp, but the unit is different. The bracket for the fuse board could be made from several different materials but as I have some experience with a heat gun and Lexan, I used the Lexan.

[PharmGeek]

I have mine in and running at 14.79v

All looks well so far

I need to copy your lexan l bracket trick - where do I get that....HD?

Mine was a swap for the parallax 555 on my 2014 bunkhouse

We had a small snafu - I was sent the 55amp boondocker that is the same unit just not the deck mount - we are going to try out this way and if all looks good then I may keep it

Pics to come

Nice job!!


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[68 Overlander]

Excellent work Tommie!

[68 Overlander]

Originally Posted by Msmoto

Yes, my Serenity has the 50 Amp, so one must use a 60 Amp, Converter/charger. Before I installed this I spoke with Airstream who confirmed the standard charger would simply apply a full charge to the batteries and not go into a float stage. Thus, it was recommended the water be checked as often as once monthly.

Then I spoke with Randy at BestConverter - Converters, Inverters, Electrical Supplies, Electronics and he gave me the recommendation for the converter. What this does is to charge the batteries, then go to float, and PM4B models now include built-in conditioning cycle to prevent stratification that can lead to battery sulfating.

The installation is about the same whether 30 or 50 Amp, but the unit is different. The bracket for the fuse board could be made from several different materials but as I have some experience with a heat gun and Lexan, I used the Lexan.

One clarification about "one must use 60 amp" Ms Tommie. Airstreams are built and configured with either 30 or 50 amp service and that relates to the incoming AC service. A second air conditioner is typically the reason for the upgrade to 50 amp service since they are normally connected to a 20 amp AC circuit and will often draw close to, or more than 15 amps (X2) Two air conditioners might continuously trip a 30 amp service breaker, especially if anything else AC was running. Even running the air conditioner and a microwave can trip 30 amp service breaker and many Airstreams have a switch to turn one or the other off to prevent that. That is the reason for 50 amp service.
Converters on the other hand are rated in their "DC" output and have really no relationship to the AC service except they use some. In other words, a 55-60 amp DC converter would typically use only about 7 AC amps so you could use a 30, 45, 60, 75 or even 100 amp converter/charger and it would still run on either 30 OR 50 amp service. Again, nice install. One of the best I've seen.

[Msmoto]

My understanding of the electrical aspects of this are entirely based upon what a reliable source recommends…. so, I appreciate the explanation, Randy.

One more minor "advantage" of the new converter/charger is the location and having it freestanding in a large space, the cooling fan not located at the open grill, means when the fan comes on it can hardly be heard. The original was extremely noisy and it would seem from my perspective if the factory had installed the fan on the other end of the converter, it could have eliminated some noise.

Also, i will be running a temperature probe into the compartment where the new unit is located and monitor the ambient temperature to assure it is adequately ventilated, especially in the summer months. And, if it is warm, i have some computer ventilation fans which can easily be installed and operate off a temp sensing switch. The other perk is there are several unused sources of power under there…LOL

At PharmGeek…. Lexan or Clear Polycarbonate Sheet can be purchased at various building suppliers. However, I would suggest finding a company who cuts Lexan for special purposes, and attempting to purchase some scrapes. Still expensive, but it is a very usable material. Heating must be done with a good deal of caution as the "bending" temperature is just below that where it begins to bubble, and this is not desirable. Also, Lexan does not do well in UV light, eventually deteriorating and losing its strength. So, when in the elements it is best to protect with a coat of paint. If you look carefully at the photo of my Serenity, on the front of the roof:
http://www.airforums.com/forums/f458...-125752-2.html
What you will see is a small projection, fashioned from Lexan, painted gray, and this is to protect the Sirius/XM antenna from a potential tree branch. So, Lexan is great stuff. In my 2009 Int 27 FB, I had built some additional cabinetry, supported by Lexan "legs".http://www.airforums.com/photos/show...mageuser=31871

Be well….

[PharmGeek]

Thank you - I will attempt and find it today and complete my install - I doubt mine will end up looking as neat as yours

Randy - do you think mine without a case will get dust and dirt too much on it over time? I thought a perk of this unit is even better cooling if not




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[68 Overlander]

Originally Posted by PharmGeek

Randy - do you think mine without a case will get dust and dirt too much on it over time? I thought a perk of this unit is even better cooling if not

No I don't think so because they are open in the power centers the are originally designed with too. Same with the other brands. They might get a little dusty over time and you can certainly us an aerosol duster periodically.

[PharmGeek]

Perfect - I'm wakeboarding now but later am gonna fiddle with it


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[Tater]

Randy, I have mine as well and will get it in this week. Pharm hit what I ws wondering about as well.

[68 Overlander]

Something else to consider would be a bent piece of sheet metal L shaped to hold the fuse board.

[Msmoto]

One more little item…. my trailer has a removable panel which accesses the large space where the converter/charger is located along with much of the plumbing and I think the hot water heater. This had two holes of about 1 1/4" diameter, providing ventilation. I put in three additional holes for ventilation. And, no, I do not have a photo, but the panel is under the television side of the dinette, behind the storage tray under the seat.

[PharmGeek]

Why is this 555 converter like seemingly 4x heavier? I guess the box in part - did the 60 unit deck mount with box to enclose seem less heavy? If so why - generally curious

Noticed that this 555 box is sealed up with like rivets or something - no way to take it out of that box hardly it seems - I wonder how much dust accumulates in there with the fan blowing air in there


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[Msmoto]

The unit I removed weighed in at 4.4 kg or about 9 lbs 11 oz. with short wire leads still attached. The shipping weight on the new unit is 7 lbs. I have no idea why the old one is heavier, but the box is larger, has brackets on each side used to mount it to the cabinet, and has the mounting points for the fuse block.

[PharmGeek]

I picked up some materials - channeling as a base for the unit and the flashing type piece as my board mount (not as nice looking but will do fine


Almost done



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[PharmGeek]

I have not yet attached all to the floor yet and am thinking about some kinda tacky 3m type a deal I could use to secure everything that I could fairly easily remove when needed

It may be really annoying to get back in there to secure the back parts to the floor - still contemplating that...

Not to all thinking about doing this you will need various tools to do this

A drill - bits - a hack saw - screw drivers, nut drivers perhaps - tape measure - pencil....

Note also that this pm4b-55 unit if you go that route - it has two holes to drill I to the floor ready on the one side of the unit - but not on other side - there is a metal ran on other side that I used to put a screw through bit no place for the other - no biggie - I plan on a similar 3m product for that 4th open point if attachment (if that makes sense) to secure it.

Note - I'm not super super handy but this ain't so bad - I'm almost there


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[PharmGeek]

The green ground wire is the shortest wire - all the others appear to be plenty long for the install

Green wire on this unit is doable but wish it was longer to give greater flexibility - guess that would be easy to extend....


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[68 Overlander]

It is the shortest and will be longer on the next run. All of the others should be plenty long. I've already told our manufacture it needs to be longer but extending it is fine and simple enough to do. Actually is should reach but not much slack I know. Let me know if it didn't. Easy fix.