Multi Stage Converter/Charger

[Mrjkq]

I'm sure this topic has been addressed in the past but my search turned up nothing. My batteries need to be replaced but before doing so I want to upgrade to a multi (3) stage converter. My AS is a 2016 25'FC RB & 30 AMP service. My question is what amp converter is compatible with the wiring in my trailer, 35, 45 or 55amp. Also where is the converter/charger located, is it near the breaker box?

[rmkrum]

The convertor is usually located behind the 12 volt DC fuse panel in your breaker box--the bottom half of the unit.

The convertor output is rated in the maximum number of amps it puts out when charging batteries. It has little to do with the 30 amp AC power that the Airstream runs on when connected to shore power.

That said, a 50-55 amp convertor is usually what Airstream puts in, so a similar one is enough. Suggest getting ahold of Randy at BestConvertor and discussing the swap out with him. There are models that replace the guts of the old one easily.
.
Have the model number and nameplate data from your existing convertor and fuse panel handy when you get hold of him.

[pcskier]

Originally Posted by Mrjkq

I'm sure this topic has been addressed in the past but my search turned up nothing. My batteries need to be replaced but before doing so I want to upgrade to a multi (3) stage converter. My AS is a 2016 25'FC RB & 30 AMP service. My question is what amp converter is compatible with the wiring in my trailer, 35, 45 or 55amp. Also where is the converter/charger located, is it near the breaker box?

You want the PD4655. As stated earlier, the unit is the lower section of your power center. Changing mine out on my 23 FB today or tomorrow.

Here is an extensive thread with photos of the installation provided by Snowy, one of our members on here. Very helpful.

http://www.airforums.com/forums/f449...es-162905.html

http://www.bestconverter.com/4600-se...its_c_133.html

[Mrjkq]

Originally Posted by pcskier

You want the PD4655. As stated earlier, the unit is the lower section of your power center. Changing mine out on my 23 FB today or tomorrow.

Here is an extensive thread with photos of the installation provided by Snowy, one of our members on here. Very helpful.

http://www.airforums.com/forums/f449...es-162905.html

http://www.bestconverter.com/4600-se...its_c_133.html

Thanks for the info & links. My electrical ability is quite limited, so I need to find a RV Tech in Southwest Florida to accomplish this. Ironically, earlier today I contacted JC as I have a service appointment in July and they don't do these upgrades. That surprised me.

[Wconley]

I changed mine out to the PD4655 last weekend. It took a little between 1-2 hours. If you order the remote pendant you can skip replacing the 12v circuit board and be done in under an hour. I followed the illustrated instruction thread and ordered it from Best Converter

[dasams]

Originally Posted by Wconley

I changed mine out to the PD4655 last weekend. It took a little between 1-2 hours. If you order the remote pendant you can skip replacing the 12v circuit board and be done in under an hour. I followed the illustrated instruction thread and ordered it from Best Converter

+1 The batteries in my 2017 AS were dated May 2016 and were dead seven months after we took delivery thanks to the stock Parallax unit. Last week, I did the PD4655 swap following the threads referenced above. And definitely buy the pendant that simplifies the process and allows you to monitor the system with just a glance. GL, Dave

[gandttimes]

Got my 2014 fall of 13 and batteries were gone in 3 months. Dealer replaced them free and I installed the PD4655 and batteries are still performing great after 3 years of always being chard one way or another. Actually waiting for them to die so I can replace with 2 6V, but since they are still going strong I can't justify it yet.🤔

[pcskier]

Originally Posted by Mrjkq

Thanks for the info & links. My electrical ability is quite limited, so I need to find a RV Tech in Southwest Florida to accomplish this. Ironically, earlier today I contacted JC as I have a service appointment in July and they don't do these upgrades. That surprised me.

It will be quite straight forward for an RV tech to install. I'd recommend changing to the included new circuit board as well as getting the remote pendant, so that you always have the option for both, i.e. being able to see the charge status by opening the cover, or using the pendant that mounts outside the cover. But that's just me.

[Mrjkq]

Ordered it today from Best Converter, also have a RV Tech lined up for the install. Thanks again everyone for your imput!

[Michael_TW]

hello, thanks to everyone posting their information. there are some gaps though. My family are recent owners of a 25' FB Flying Cloud. From what I can tell, a multi-stage converter if installed directly as a replacement for the existing converter is useless and would have no impact on the battery performance. This would agree with some of the experienced posters here, and with the original poster. My basis is the discussion from the Parallax website. Most of the discussion would suggest that deep discharging the batteries is more likely the culprit than the converter. Also it seems like maybe just installing some cabling to quickly isolate the batteries with some alligator clips to hook up a proper 12V battery charger directly to a 120V generator might be a more cost effective solution, and would allow one to easily maintain the batteries when the trailer is on shore power or not in use. Any comments?

Follow-up Question: is everyone who is installing the multi-stage converters, installing battery isolation cabling/switches? are there separate outputs on the multi-stage converters that isolate the batteries from the regular DC supply (eg. two separate outputs?)

see below:
http://www.parallaxpower.com/faqs
Q: My friend has a "smart charge controller" that plugs into his converter system. Why hasn't Parallax offered a "smart" charger option for my unit?
A: The issue we have with "smart charger technology" (when used in an RV) lies more with the application of the technology than the technology itself. In a typical RV 12 volt electrical system, the converter/charger and the battery or battery bank is connected in parallel with the rest of the 12 volt distribution system. In "parallel" means where the charging source (converter/charger) positive and negative output is electrically connected to both the battery bank positive and negative, and the 12-volt distribution system positive and negative, at the same time. The voltage output of the converter "smart charger" is based on a "detected" battery voltage. The converter "smart charger" claims to "monitor" and respond to battery condition while connected to the entire 12 volt system. Unless the charging source (converter) has a separate or isolated charging output, we do not agree that a converter or charger can effectively differentiate requirements of the batteries from other 12 volt loads while simultaneously connected to the rest of the 12 volt distribution system in the RV.

Detected use or voltage change on the RV 12-volt load system (i.e. lights, pumps, etc. being turnedon) generally keeps these devices at a 13.6 -13.8 "float" voltage. This raises the question whether any real additional benefit is being provided to the battery bank unless the coach remains in a "non-use" storage condition. If a converter "smart charger" is only connected to the battery bank and can therefore monitor only battery voltage or current, and is not also connected "in parallel" with the 12 volt distribution system, we have no problem with the application of "smart charger technology".

[Michael_TW]

Hello all, I originally meant to reply to a different thread, "Do we need a multi-stage converter?" but the discussion is still relevant.

[alano]

Originally Posted by Michael_TW

hello, thanks to everyone posting their information. there are some gaps though. My family are recent owners of a 25' FB Flying Cloud. From what I can tell, a multi-stage converter if installed directly as a replacement for the existing converter is useless and would have no impact on the battery performance. This would agree with some of the experienced posters here, and with the original poster. My basis is the discussion from the Parallax website. Most of the discussion would suggest that deep discharging the batteries is more likely the culprit than the converter. Also it seems like maybe just installing some cabling to quickly isolate the batteries with some alligator clips to hook up a proper 12V battery charger directly to a 120V generator might be a more cost effective solution, and would allow one to easily maintain the batteries when the trailer is on shore power or not in use. Any comments?

Follow-up Question: is everyone who is installing the multi-stage converters, installing battery isolation cabling/switches? are there separate outputs on the multi-stage converters that isolate the batteries from the regular DC supply (eg. two separate outputs?)

see below:
http://www.parallaxpower.com/faqs
Q: My friend has a "smart charge controller" that plugs into his converter system. Why hasn't Parallax offered a "smart" charger option for my unit?
A: The issue we have with "smart charger technology" (when used in an RV) lies more with the application of the technology than the technology itself. In a typical RV 12 volt electrical system, the converter/charger and the battery or battery bank is connected in parallel with the rest of the 12 volt distribution system. In "parallel" means where the charging source (converter/charger) positive and negative output is electrically connected to both the battery bank positive and negative, and the 12-volt distribution system positive and negative, at the same time. The voltage output of the converter "smart charger" is based on a "detected" battery voltage. The converter "smart charger" claims to "monitor" and respond to battery condition while connected to the entire 12 volt system. Unless the charging source (converter) has a separate or isolated charging output, we do not agree that a converter or charger can effectively differentiate requirements of the batteries from other 12 volt loads while simultaneously connected to the rest of the 12 volt distribution system in the RV.

Detected use or voltage change on the RV 12-volt load system (i.e. lights, pumps, etc. being turnedon) generally keeps these devices at a 13.6 -13.8 "float" voltage. This raises the question whether any real additional benefit is being provided to the battery bank unless the coach remains in a "non-use" storage condition. If a converter "smart charger" is only connected to the battery bank and can therefore monitor only battery voltage or current, and is not also connected "in parallel" with the 12 volt distribution system, we have no problem with the application of "smart charger technology".

I wouldn't look to Parallax for justification why a smart charger might make sense for you.

You can already isolate your batteries by selecting the "Store" position, so there's no need to isolate your batteries with cabling. If you want to charge your batteries for an extended period with an external charger, just connect the charger directly to the battery terminals with the use/store switch in the "store" position.

There are many reasons why a multi-stage battery charger makes sense. However, many folks get by without upgrading their converter. Some by paying careful attention to how they manage battery charging. Others are perhaps lucky. I haven't bothered with upgrading my converter because I have a three-stage battery charger built into my solar charger.

[uncle_bob]

Hi

If you want to extend the life of a new set of batteries, get a charger with a temperature sensor on it. That more than any 3, 4, 5, 687 stage charger will extend their life span.

Bob

[alano]

Originally Posted by uncle_bob

Hi

If you want to extend the life of a new set of batteries, get a charger with a temperature sensor on it. That more than any 3, 4, 5, 687 stage charger will extend their life span.

Bob

And like Bob says, my solar charger includes a battery temperature probe!

[Michael_TW]

Thanks Al, good point on the store button, I was planning on looking at the circuit schematics to see where and how it is disconnected (I am assuming on the positive side, maintaining a common ground on the frame).

I think you misunderstood the Parallax comment. Unless the multistage converter is disconnected from everything but the batteries, they don't appear to do much. Since there will always be loads on the 12V DC bus, the multi-stage mode apparently never gets activated except for the quick charging part at the beginning. You're point of hitting the "store" button, and allowing the solar to charge the batteries makes sense. So,if you are running a generator it would seem the easiest thing to do is use a dedicated battery charger ($80), hit "store", and connect some alligator clips to get the fast charge.

I am assuming that maybe the multi-stage converter has a trickle mode that gets activated by the thermometer? Is that how it saves the batteries? Does anyone understand how a multi-stage converter drops out of 13.6 V?

[uncle_bob]

Originally Posted by Michael_TW

Thanks Al, good point on the store button, I was planning on looking at the circuit schematics to see where and how it is disconnected (I am assuming on the positive side, maintaining a common ground on the frame).

I think you misunderstood the Parallax comment. Unless the multistage converter is disconnected from everything but the batteries, they don't appear to do much. Since there will always be loads on the 12V DC bus, the multi-stage mode apparently never gets activated except for the quick charging part at the beginning. You're point of hitting the "store" button, and allowing the solar to charge the batteries makes sense. So,if you are running a generator it would seem the easiest thing to do is use a dedicated battery charger ($80), hit "store", and connect some alligator clips to get the fast charge.

I am assuming that maybe the multi-stage converter has a trickle mode that gets activated by the thermometer? Is that how it saves the batteries? Does anyone understand how a multi-stage converter drops out of 13.6 V?

Hi

Ok, so there's still some confusion:

1) The temperature probe continuously adjusts all the voltages involved. The voltages (float, charge, boost) are all higher at low temperature and lower at high temperature. There is no "trigger" involved.

2) All multi stage converters (that are properly designed) have a current setting below which they ignore the current. Some batteries pull current even when in "float". If your parasitic loads are below this current threshold, they don't matter.

3) With a multi-stage, you can source full current (or at least full power) at any point in the process. The drop in / switch out stuff is only trying to figure out what the battery needs. If it makes a mistake, it's only by a modest amount.

4) Different battery construction approaches require different voltage trigger points. Different lead acid chemistries require different trigger points. A better charger / converter will let you program all of this stuff.

Yes, lots of details.

Bob

[dcasr]

Originally Posted by Mrjkq

I'm sure this topic has been addressed in the past but my search turned up nothing. My batteries need to be replaced but before doing so I want to upgrade to a multi (3) stage converter. My AS is a 2016 25'FC RB & 30 AMP service. My question is what amp converter is compatible with the wiring in my trailer, 35, 45 or 55amp. Also where is the converter/charger located, is it near the breaker box?

______________
Whether you choose the 45 amp charger or the 55 amp charger is impacted by your Airstream's input amperage from the street. If you have a 30 amp cord from the street you have around 3400-3600 watts at 115-120 volts to work with. The 45 amp battery charger will use/take 750 watts from that to continuously power your charger and produce the 45 amp input to your battery. If you choose the 55 amp battery charger it will charge your battery a little faster, but it draws 950 watts from your 3400-3600 watts available coming in from the street. I have a 30 amp system from the street (3400-3600 watts) and I chose the 45 amp charger so I wouldn't use up quite as much of my 3400-3600 watts available, but it is a judgement call for each Airstreamer. If you have a 50 amp cord and system you have no problem at all with the 55 amp charger and should go for it.

I have found that some older campgrounds, Good Sam and KOA, when they are full and its summer, will have a drop on their posts from 120 volts down to 108 or lower and that is worrisome because some of our high tech stuff can be damaged by low voltage, and when incoming voltage is down to 108vac, the wattage is down to 3240 on a 30 amp post/cord. Buy an inexpensive plug-in voltage/wattage/amperage meter to use on the post and inside your unit so you always know what's really going on.

[Fred L]

dcasr,
My understanding of the 55 amp rating on the converter is that it is relative to the DC supply out to the circuits from the converter and not to do with AC supply that is coming in.

I could easily be all wrong since I am not an electrical engineer or similar experience, but read through the linked thread in post #3 by Pat/pcskier and let me know your take.

[uncle_bob]

Hi

The converter is simply a battery charger with a different name on it. If you have a trailer that is likely to have the larger batteries in it, you get the bigger unit. Matching the output of the unit to the amp hours on the battery helps keep everything happy.

Bob

[dcasr]

Originally Posted by Fred L

dcasr,
My understanding of the 55 amp rating on the converter is that it is relative to the DC supply out to the circuits from the converter and not to do with AC supply that is coming in.

I could easily be all wrong since I am not an electrical engineer or similar experience, but read through the linked thread in post #3 by Pat/pcskier and let me know your take.

______________


You are correct that the 55 amp or 45 amp or 60 amp rating when speaking of converters/chargers, is the output to the 12 v system which includes the 12v battery and appliances. The output onto the 12v line is proportional however to the wattage draw off of the incoming 30 amp or 50 amp power from the street or generator. The 45 amp 12v DC chargers typically draw about 750 watts 120vAC from the available incoming 120v amperage /wattage, and the 60 amp 12vDC conversation/chargers put 60 amps into the 12vDC system but drawn down around 950-1000 watts from the incoming street or generator 120vAC power available. For those of us with Airconditioning, microwave, etc and on a 30 amp 120vAC street power the wattage available is about 3400-3600 watts and a larger 60 or 70amp 12vDC converter/charger will draw drown too much wattage from our available 120vAC system. Those with 50amp 120vAC incoming street power are less likely to worry about this wattage drawn down as they have more of it to start with. Hope this clarifies things.
+dcasr