PD4655 Install with Pictures

[The Colonel]

Originally Posted by dblee1950

For those that have the 4655 installed, how long does it take to get to the slow blink state? Mine has been in for a few days now and all I see is the normal chg blink every 1-2 seconds. My AS is just sitting with shore power on and not being inhabited right now. I can cycle thru the states so that seems ok

Bump?

[68 Overlander]

Originally Posted by dblee1950

Bump?

It's 48 hours of no voltage change (~.3 volts is the threshold) If you go in the Airstream and start flipping on lights or other DC stuff you keep resetting the timer.

[68 Overlander]

Also, the sniffers (Lp smoke detectors) can sometimes reset the timer so if you want to rule out any voltage change, pull those fuses for long term storage. Just don't sleep in the Airstream if you do (Why did I have to say that part?)

[The Colonel]

Thx 68. Didn't want to seem paranoid, just wanted some + feedback on installation.

[pcskier]

Maybe Randy can chime in here.

I will be installing my 4655 upgrade I got from Bestconverter, but am curious about something.

While I know the voltage starts 14.4 for boost charge, then then down to 13.6 for normal and 13.2 for float mode, what are the accompanying amps?

Is the amperage output higher at boost charging, and drops down as the battery charges? How does amperage play into the whole charging puzzle? For instance, with my two Interstate Group 24s, I have a total of 168 amp hours of storage, so 84 hours useable to avoid draining the batteries more than 50%. So using power in the trailer that draws 8 amps, would give me roughly 10 hours of power.

Is the reverse correct then...that charging at 8 amps output would take 10 hours, 16 amp output would take 5 hours, etc? And in that case, what is the output of the PD4655?

I also am curious about generator output. My Honda EU 2000 puts out 13-16 amps AC, i.e. plugged in as shore power, but what would the converter put out to charge the batteries. It also puts out 8 amps at 12 volts if the DC output is used and hooked directly to the batteries. In that case, I'd be at 10 hours of generator useage to replenish my 50% depleted batteries.

Would it be faster/more efficient to run the generator AC output to the converter to charge the batteries?

[68 Overlander]

Originally Posted by dasams

I took delivery of a brand spanking new 2017 FC in Aug. We hit the road and have been staying in full hook-up parks the whole time. Guess what? We did some beach boondocking down in Baja and my May 2016 batteries are fried Had to buy a new pair at the Costco in Cabo san Lucas. Now back in the US and am placing my order for the PD 4655 with BestConverter.

Why oh why did AS install that POS Parallax unit? I'd gladly have paid them the $25 difference in the OEM cost

This is how it works...Parallax had them for a LONG time because Parallax makes a decent reliable product, but don't stop reading. Most of you guys aren't replacing them because the failed, but rather because they are failing your batteries often multiple times. Airstream could care less after the warranty period is up. Parallax will make it through the warranty period or they wouldn't use them. That said...

I don't have the exact numbers but I expect most new Airstream buyers are first time RV owners at or nearing retirement age with a little coin in the 401K and want a good trailer. Or a younger couple with some jingle to spend.

This topic does not often come up at the dealership because Joe Public is none the wiser. It comes up 6-12-24 months later when they find you guys and can't understand why they buy expensive batteries every year or two.
Progressive Dynamics and the Boondocker converters know how to extend the life of batteries and the proof is in the sales of the aftermarket upgrades.

Most of the vintage crowd has known this for years and have already upgraded to a modern 3 or 4 stage converter/charger.

I was in Elkhart (not where airstreams are built but you knew that) but where 95 percent of all RVs are built and learned Airstream might have switched to the WFCO brand exclusively. They are the cheapest on the market for OEM. Somebody might be able to confirm as I know some models already use them.

Finally, we do send a lot converters to Airtstream dealerships for customers that won't take delivery unless its upgraded before signing the final papers so that is an option but they usually won't pay for it unless it's a deal breaker.

[68 Overlander]

Originally Posted by pcskier

Maybe Randy can chime in here.

I will be installing my 4655 upgrade I got from Bestconverter, but am curious about something.

While I know the voltage starts 14.4 for boost charge, then then down to 13.6 for normal and 13.2 for float mode, what are the accompanying amps?

Is the amperage output higher at boost charging, and drops down as the battery charges? How does amperage play into the whole charging puzzle? For instance, with my two Interstate Group 24s, I have a total of 168 amp hours of storage, so 84 hours useable to avoid draining the batteries more than 50%. So using power in the trailer that draws 8 amps, would give me roughly 10 hours of power.

Is the reverse correct then...that charging at 8 amps output would take 10 hours, 16 amp output would take 5 hours, etc? And in that case, what is the output of the PD4655?

I also am curious about generator output. My Honda EU 2000 puts out 13-16 amps AC, i.e. plugged in as shore power, but what would the converter put out to charge the batteries. It also puts out 8 amps at 12 volts if the DC output is used and hooked directly to the batteries. In that case, I'd be at 10 hours of generator useage to replenish my 50% depleted batteries.

Would it be faster/more efficient to run the generator AC output to the converter to charge the batteries?

The boss is your battery's internal resistance. As they charge, they resist as they near full charge. The 4655 has 55 amps ready to go, less any other DC loads since it's shared.

Voltage is the force that attempts to overcome and force amps/current into your batteries. This is why I don't recommend big is always better. Sometimes you won't realize the higher amp output in smaller battery banks. 55 Amps is normally fine for up to 2-4 batteries unless you bring them way down like you're not supposed to anyway.

Your EU 2000 will run that converter fine and you will see faster charging using it as a power supply for your converter than using the DC part of the generator. The converter will have the ability to put out ALL of its output. Unless somthing has changed, I'd ignore its DC charging function and use your converter instead. It's a better charge profile anyway.

[pcskier]

OK, massively confused here!

I ordered a PD4635. This is because I have a Flying Cloud 23 FB. The trailer is in storage, so I looked at the manual, which referred to Parallax 7300, and the wiring schematic for the 23 FB states "30A Main Circuit."

So in looking at the options on Bestconverter.com, it shows the PD4635 as being 35 amps, and the 4655 being 55 amps. So I ordered the 4635.

While I visited the trailer the other day, I took a photo of the power center just for the heck of it to double check. The one I have is the Parallax Model 7355, 55 Amp model. Why would there be a 55 amp model in a 30 amp trailer? Does Airstream just use one model that covers both 30 amp and larger 50 amp trailers, so it's overkill on the 30 amp trailers but also covers the 50 amp trailers?

In any case...according to the cross-reference chart on Bestconverter.com, the PD4655 is the replacement for the Parallax 7355. Do I need to return the 4635 and replace with a 7355? (It's still in the box).

Boy do I feel dumb but I figured since I had a 30 amp trailer I had a 30 amp converter And THANKS for answer to previous question re: direct generator charging vs Generator feeding the inverter. Good to know!

[68 Overlander]

Originally Posted by pcskier

OK, massively confused here!

I ordered a PD4635. This is because I have a Flying Cloud 23 FB. The trailer is in storage, so I looked at the manual, which referred to Parallax 7300, and the wiring schematic for the 23 FB states "30A Main Circuit."

So in looking at the options on Bestconverter.com, it shows the PD4635 as being 35 amps, and the 4655 being 55 amps. So I ordered the 4635.

While I visited the trailer the other day, I took a photo of the power center just for the heck of it to double check. The one I have is the Parallax Model 7355, 55 Amp model. Why would there be a 55 amp model in a 30 amp trailer? Does Airstream just use one model that covers both 30 amp and larger 50 amp trailers, so it's overkill on the 30 amp trailers but also covers the 50 amp trailers?

In any case...according to the cross-reference chart on Bestconverter.com, the PD4655 is the replacement for the Parallax 7355. Do I need to return the 4635 and replace with a 7355? (It's still in the box).

Boy do I feel dumb but I figured since I had a 30 amp trailer I had a 30 amp converter And THANKS for answer to previous question re: direct generator charging vs Generator feeding the inverter. Good to know!

Attachment 281865

Don't feel dumb, it happens all the time. Converters are rated in their DC amp output, not the AC input which is eaither 30 or 50 amp service.
I'd exchange it and frankly wish we didn't even have to fool with the 4635 or 4645 but FOR SOME REASON they want to confuse the people. A 55 amp converter is fine for one or 4 batteries. In 15 years I've had exactly 0 people wish they had a smaller than 55 amp unit but that's not to say the 35 won't keep up.

[pcskier]

Originally Posted by 68 Overlander

Don't feel dumb, it happens all the time. Converters are rated in their DC amp output, not the AC input which is eaither 30 or 50 amp service.
I'd exchange it and frankly wish we didn't even have to fool with the 4635 or 4645 but FOR SOME REASON they want to confuse the people. A 55 amp converter is fine for one or 4 batteries. In 15 years I've had exactly 0 people wish they had a smaller than 55 amp unit but that's not to say the 35 won't keep up.

AHHHH that makes sense AC input rating vs. DC output.

I sent you an email to Bestconverter.com and your gmail address about this, I definitely want to do the exchange. Let me know the process, I guess I ship mine back then you can ship out a new one I after pay the difference plus shipping on the new one. I also will add the pendant, seems convenient to select boost charge when topping off with the genny. Thanks, I'll wait for a reply back on email with shipping instructions...just need correct address.

Peter K

[pcskier]

I am replacing my Parallax 7355 with a PD4655, but am still always researching...probably more than I should. Parallax has replaced the 7355 with the 8355 series, and the description on their web site state:

'The 8355 is a 30 Amp Power Center with a three stage 55 Amp Converter Charger'

Do we assume they have finally upgraded to a 3-stage system, or was the 7355 3-stage as well--but I'm understanding something incorrectly? Everything I've every read on the forum states that the Parallax 7300 series was a "one--stage" unit (which to me means it was either "on" or "off".) And would 'cook' the batteries because it was 'on' too much. (That's the simple way I inferred it)

Any illumination on this?

I need to stop trying to become an expert...and just frigging go camping.

[glcmranger]

Its NOT! I replaced my 8355 with the PD4655. Call Randy at Best Converter to verify. He'll probably respond here on the forum.

[pcskier]

Originally Posted by glcmranger

Its NOT! I replaced my 8355 with the PD4655. Call Randy at Best Converter to verify. He'll probably respond here on the forum.

I've been convinced enough to install a pd4655 but am just really curious about what is "3 stage" about the Parallax 8355. Their site has limited technical info.

[68 Overlander]

Originally Posted by pcskier

I've been convinced enough to install a pd4655 but am just really curious about what is "3 stage" about the Parallax 8355. Their site has limited technical info.

It's not, period. I heard they might start calling it one but it's not. They flow through my warehouse everyday to those that want them but it's not a 3 stage. It's a single stage. When they want to get serious about a multi stage, I will be there but they just won't listen. I've know Marty Redd, their lead tech for at least 12 years and his pitch is always about how the converter doesn't know what it's connected to, the battery or the DC system. Nothing is going to change soon, the engineers are not RV people, they are power supply people. They have it all figured out apparently with their marketing but still don't make one. I have dozens or hundresd of them in my warehouse of all models and they are single stage. They sell to people that just insist on what was in there stock. Some Airstream but a bunch of ole Magnetek since Parallax bought them years ago and it translates over on their web and ours.

[68 Overlander]

Geez, I sound like a salesman up there but guys, it's just what works. I'm trying my best to make it best I can and come up with the best solutions. Everybody has an opinion but I can only learn more from you guys if you will keep telling me what you want in a $200 converter/charger. I can certainly provide a $500-1000 charger that doesn't make sense unless you live to be 150. If you are sold on temp compensation, I have 11 years on my Lifelines (outside) in Idaho with a standard converter. You can't sell me with the chemistry claims you read for a travel trailer battery unless its free and even the data is not there. Just theory. I'd rather have a 4 stage unless I was storing in Greenland ha. Same with MPPT solar controllers on most Rvs. Been through it enough times but value opinions.

[pcskier]

Originally Posted by 68 Overlander

Geez, I sound like a salesman up there but guys, it's just what works. I'm trying my best to make it best I can and come up with the best solutions. Everybody has an opinion but I can only learn more from you guys if you will keep telling me what you want in a $200 converter/charger. I can certainly provide a $500-1000 charger that doesn't make sense unless you live to be 150. If you are sold on temp compensation, I have 11 years on my Lifelines (outside) in Idaho with a standard converter. You can't sell me with the chemistry claims you read for a travel trailer battery unless its free and even the data is not there. Just theory. I'd rather have a 4 stage unless I was storing in Greenland ha. Same with MPPT solar controllers on most Rvs. Been through it enough times but value opinions.

We probably drive you nuts! Gonna put in the PD4655 when I get it from you next week and just forget about all this and obsess about something else! (Which will probably be adding the Trimetric monitor!) Then solar but I'll hassle Lewster with that ��

[Adventure.AS]

Originally Posted by pcskier

I am replacing my Parallax 7355 with a PD4655, but am still always researching...probably more than I should. Parallax has replaced the 7355 with the 8355 series, and the description on their web site state:

'The 8355 is a 30 Amp Power Center with a three stage 55 Amp Converter Charger'

Do we assume they have finally upgraded to a 3-stage system, or was the 7355 3-stage as well--but I'm understanding something incorrectly? Everything I've every read on the forum states that the Parallax 7300 series was a "one--stage" unit (which to me means it was either "on" or "off".) And would 'cook' the batteries because it was 'on' too much. (That's the simple way I inferred it)

Any illumination on this?

I need to stop trying to become an expert...and just frigging go camping.

I wrote to Mike Tomarchio, National Account Manager, Parallax Group, Inc. about the anecdotal stories concerning the stock Airstream power center.

Here is his reply:

"If you have a 2013 or newer Airstream that utilizes 30 amp shore power and is not a Sport model, then yes you have the 8300 series.

The 8355 offer three stages of charging to the battery. Bulk, Absorption, and Float. The battery dictates the amount of current (amps) it takes in regards of charge stage. Our system is capped at 13.8VDC on the high end and 13.2 on the low end.

1. While most battery manufacturers recommend a bulk rate of 14VDC, that is based on the battery isolated and sitting on a work bench/station hooked up to an “actual battery charger” in approximately 70 degree ambient temperature. What most well-meaning RV owners fail to understand is that the charge rates that are recommended for their batteries do not take into consideration all possible usage scenarios.

2. “4 stage” charging There isn’t a an RV converter/charger manufactured in the free world that can actual supply the recommended desulfation voltage of 15.5VDC. 15.5VDC is what every flooded cell lead acid battery manufacturer requires to stir up the electrolytes and clean the lead plates internal to the batter. 15.5VDC would cause serious damage to the sensitive 12VDC circuit boards on the refer, thermostat, etc. Should you have anything other than a flooded cell lead acid battery, you are not supposed to put it through a desulfation mode simply because there are no lead plates to experience sulfation.

3. The only true way to charge a battery is to compensate for temperature, just as most vehicles manufactured after 1995 (OBDII-equipped) have a temperature compensated voltage regulators internal to the alternator.

4. Your typical Three Stage at 14.4VDC (bulk), 13.6VDC (absorption) and 13.0-13.2VDC(float) only benefit the battery if the battery is sitting at approximately 70 degrees as those voltage provide the best charging scenario. (for that temperature)

5. Any temperature other than 70 degrees, those voltage can cause harm to the battery.

6. The reason most uneducated RV owners call us a “single” stage system is because we do not call out three specific charging voltages. Most people have come to understand 14.4, 13.6, 13.2 as stages, this is not true, those are merely voltages supplied during the stages. Bulk, absorption, and float happen naturally during the charge cycle.

7. Because of parasitic loads within the coach and the charging of the battery is not an separate from powering the entire 12VDC system within the coach, we simply do not agree that the manner in which a “three stage” converter is intended to function actually works the way they claim to. You cannot claim to monitor battery current separate foro the entire system when they are tied in parallel to each other. It is an impossibility.

8. What we offer for true multi-stage (over and above three stage) is TempAssure™, it is the only converter system on the market that can do what battery manufacturers want to be done, and that is charge based upon ambient temperature.

Should you be interested in upgraded the stock system, which is technically three stage, to true multi stage, I can sell you an upgrade kit called the 4400TAU. It is a plug and play module."

Based on this information, I think I will stick with the 8355 on my new Serenity but will likely add the temperature compensation module.

[greghoro]

Originally Posted by Adventure.AS

I wrote to Mike Tomarchio, National Account Manager, Parallax Group, Inc. about the anecdotal stories concerning the stock Airstream power center.

Here is his reply:

"If you have a 2013 or newer Airstream that utilizes 30 amp shore power and is not a Sport model, then yes you have the 8300 series."

Not necessarily true. I have 2013 25' Flying Cloud and the sticker on the converter door refers to a 7300 series, specifically 7355. It's been replaced with a PD4655.


Greg

[68 Overlander]

Originally Posted by Adventure.AS

I wrote to Mike Tomarchio, National Account Manager, Parallax Group, Inc. about the anecdotal stories concerning the stock Airstream power center.

Here is his reply:

"If you have a 2013 or newer Airstream that utilizes 30 amp shore power and is not a Sport model, then yes you have the 8300 series.

The 8355 offer three stages of charging to the battery. Bulk, Absorption, and Float. The battery dictates the amount of current (amps) it takes in regards of charge stage. Our system is capped at 13.8VDC on the high end and 13.2 on the low end.

1. While most battery manufacturers recommend a bulk rate of 14VDC, that is based on the battery isolated and sitting on a work bench/station hooked up to an “actual battery charger” in approximately 70 degree ambient temperature. What most well-meaning RV owners fail to understand is that the charge rates that are recommended for their batteries do not take into consideration all possible usage scenarios.

2. “4 stage” charging There isn’t a an RV converter/charger manufactured in the free world that can actual supply the recommended desulfation voltage of 15.5VDC. 15.5VDC is what every flooded cell lead acid battery manufacturer requires to stir up the electrolytes and clean the lead plates internal to the batter. 15.5VDC would cause serious damage to the sensitive 12VDC circuit boards on the refer, thermostat, etc. Should you have anything other than a flooded cell lead acid battery, you are not supposed to put it through a desulfation mode simply because there are no lead plates to experience sulfation.

3. The only true way to charge a battery is to compensate for temperature, just as most vehicles manufactured after 1995 (OBDII-equipped) have a temperature compensated voltage regulators internal to the alternator.

4. Your typical Three Stage at 14.4VDC (bulk), 13.6VDC (absorption) and 13.0-13.2VDC(float) only benefit the battery if the battery is sitting at approximately 70 degrees as those voltage provide the best charging scenario. (for that temperature)

5. Any temperature other than 70 degrees, those voltage can cause harm to the battery.

6. The reason most uneducated RV owners call us a “single” stage system is because we do not call out three specific charging voltages. Most people have come to understand 14.4, 13.6, 13.2 as stages, this is not true, those are merely voltages supplied during the stages. Bulk, absorption, and float happen naturally during the charge cycle.

7. Because of parasitic loads within the coach and the charging of the battery is not an separate from powering the entire 12VDC system within the coach, we simply do not agree that the manner in which a “three stage” converter is intended to function actually works the way they claim to. You cannot claim to monitor battery current separate foro the entire system when they are tied in parallel to each other. It is an impossibility.

8. What we offer for true multi-stage (over and above three stage) is TempAssure™, it is the only converter system on the market that can do what battery manufacturers want to be done, and that is charge based upon ambient temperature.

Should you be interested in upgraded the stock system, which is technically three stage, to true multi stage, I can sell you an upgrade kit called the 4400TAU. It is a plug and play module."

Based on this information, I think I will stick with the 8355 on my new Serenity but will likely add the temperature compensation module.

Mike told me on the phone they were going to start "calling" them 3 stage. That was less than two weeks ago. I just pulled one from stock, same ole 13.8 VDC its always been.
Remember this is the company that doesn't believe in 3 stage charging because they don't believe the converter knows the difference between a battery and a DC load. Argued with them for 12 years. Marty Redd is their lead tech and would repeat this over and over and over.
Now all of a sudden they are calling it a 3 stage, including those they admitted and were single stage a month ago? If you want multi stage charging, that steps the voltage, you need real a 3 stage.
Mike also doesn't understand the difference between desulfation and equalization but that statement was intended to make one think they were the same.
I sent a 4455TC to Dave at Lifeline a couple years ago. He took it to the Concorde lab. They were not impressed and sent it back. Even with temp comp on those, it doesn't change modes. All it means is that on an 80 degree day, it will single stage charge at 13.X. On a 90 degree day, again single stage at 13.X (a little lower) and so on. You never get a bulk or boost charge.
Desulfation is the periodic rise in voltage to its max for a few minutes (15) each day to mix up the electrolyte.
Equalization is a totally different procedure and a deliberate overcharge when batteries are losing capacity.
I'm not saying not to use it, just that they are skirting around the edges with terminology and it's not a 3 stage charger. Notice how he adds with all of those different voltage possibilities that its even more than a 3 stage? Come on. I like Mike, he's a great guy but I don't agree with him.

[pcskier]

Originally Posted by Adventure.AS

I wrote to Mike Tomarchio, National Account Manager, Parallax Group, Inc. about the anecdotal stories concerning the stock Airstream power center.

Thanks for doing this, very enlightening.

At the end of the day, I am going to stick with my upgrade to the PD4655, based on the following:

1. Anecdotal evidence. This forum, and other groups, and friends with Airstreams, all report the same result so often: batteries dying after just a year or two, and these are usually folks who keep their coaches plugged in at home or in longer (up to a week or more) stays in RV parks.

2. I have read a ton of data both here, as well as sites dedicated to battery science, as well as battery manufacturer sites. One thing that seems to be consistent is that to get a battery as close to a FULL charge as possible, it requires 14+ volts to get there. Volts are like pressure from an air compressor. You can set a compressor to 50 lbs and run it forever but it will never get your tire to 60 lbs. the 13.6V that Parallax admitted to you was their max voltage simply is not enough. The PD4655 going to 14.4 on bulk charge (time managed by the charger) is going to do a better job.

3. I have read too many reports of the markedly increased performance, as well as battery life, people have experienced by changing out the charger, to ignore it any longer.

I have read statements suggesting that most RV power centers are really designed for those who stay mostly plugged in and rarely rely on battery power. Which for those types of RV'rs, that's fine. But when you are off grid for a day or two and your fried batteries crap out after 24 hours of light useage, and they are less than a year old...something isn't right.

I'm anxious to see what my mileage will be when I change mine out, combined with a better practice of battery care.