Upgrade old Magnatek converter or replace?

Parallax TempAssure adjusted voltages are a bit low in all conditions for expecting a fast charge from a generator. Voltage sag is also poor at full load. Fine if mostly plugged in. Otherwise PD and IOTA are better with no compensation.
JMHO

Bobbo wrote:
If the 8355 comes with TempAssure already installed, I will return the PD4655V. If it is not already installed, I would have a bear of a time getting the temperature sensor to the battery. The converter/charger is on the wrong side of the trailer, and halfway down the length. On top of that, the belly of the trailer is enclosed, so I can't just go through the floor and fasten it under the trailer.

You are correct that the sensor is on the ring lug that goes on the battery post (ISTR PT insists it matters pos or neg post, but can't remember which) BUT the main thing is to get it to the same temp as the battery instead of inside the rig where it is nice and warm or cool compared with outside ambient.

Way to fussy to say battery temp (higher when being fast charged) is not the same as ambient. Especially when it is mostly the Float voltage that matters if you have Flooded batts and the battery doesn't heat up doing that.

So--just run the wire to the outside anywhere you can get it out from where the converter is and use the same ambient temp as the batteries "feel" for your temp adjustment. Of course if you have AGMs inside where it is also nice and warm or cool compared with outside, then you don't need temp adj anyway--BUT the TempAssure module is more than that--it enables the extra boost, which is a key feature.

Parallax removed the voltage curve graph but here is something from Best converter:

https://bestconverter.3dcartstores.com/assets/images/Parallax/4400/4455%20Voltage%20Curves.pdf

Chris Bryant wrote:
Owners Manual

Forum is being broken- trying to quote from that, but look at the optional TempAssure module, which I assume Airstream would include, given that they don't really give those things away :)

Parallax 8300 manual wrote:
TempAssure™ (Patent US 7,245,109)

Your 8300 system may include the (optional) TempAssure™ module and sensor
cable. When properly installed, the TempAssure™ system employs technology that
allows the output voltage of the converter to be varied by the temperature of the RV’s
“house” battery system. The benefit of this feature helps to provide a more appropriate
charging voltage for the “house” battery system exposed to varying ambient
temperatures. For example, in cold climates the output voltage of the converter will be
increased, which results in a more fully charged and maintained battery. In hot climates
the output voltage of the converter will automatically lower, which will aid in reducing
excessive out-gassing of the battery caused by the battery requiring a lower “float”
voltage.
Also with the addition of the TempAssure™ module and sensor cable, the 8300 series
converter will automatically start out in a “boost” mode for the first 4 hours of operation
every time the 8300 series converter is powered “on”. The output voltage of a
TempAssure™ equipped 8300 series converter will still be temperature compensated,
even while in “boost” mode.
Your RV manufacturer’s installation may also allow you to manually trigger the “boost”
function by pressing a switch. (optional wiring configuration)
While the 8300 series converter with the addition of the (optional) TempAssure™
module is designed to provide a better means of charging and maintaining the “house”
battery, Parallax Power Supply strongly recommends proper battery maintenance be
performed by the owner on non-maintenance free batteries following the battery
manufacturer’s recommendations.
DO NOT allow the battery cell plates on non-maintenance free batteries to become
exposed to the air. Poor battery performance will result.
Parallax Power Supply will not be responsible for battery failure resulting from improper
battery maintenance.

Doesn't really give a lot of details on voltages, boosts and reduces only. I am going to contact Randy at BestConverter.com and ask his take on the 8355 w/TempAssure. I will post his response.

If the 8355 comes with TempAssure already installed, I will return the PD4655V. If it is not already installed, I would have a bear of a time getting the temperature sensor to the battery. The converter/charger is on the wrong side of the trailer, and halfway down the length. On top of that, the belly of the trailer is enclosed, so I can't just go through the floor and fasten it under the trailer.

The 8300 appears to have a 4400 as its lower portion instead of the 7300. I had a 4455TC and it was very good (until I accidentally fried it--RIP!)

However, unless it has the TempAssure module in it (it just plugs in--easy!) it will not do the half volt jump for boost, so it is about same performance as the 7300 (also good for a single voltage 13.8) as is. If you get the 4400 with no TempAssure, be sure to get one--BIG DIFF in performance.

http://www.bestconverter.com/Parallax-Paramode-with-TempAssure_c_104.html

You are far better off with the PDI unit.

Owners Manual

Forum is being broken- trying to quote from that, but look at the optional TempAssure module, which I assume Airstream would include, given that they don't really give those things away :)

Bobbo wrote:
The Parallax website has nothing on this.

???

http://www.parallaxpower.com/8355-power-center-8355

Special Features:
30 Amp Shore service; 11 Position fuse block with blown fuse indicators; TempAssure option ready; durable steel enclosure

http://www.bestconverter.com/8300-Series_c_87.html

-Lqdskier wrote:
That sounds like a great option, Bobbo. Do I need any additional components or is the kit complete? I pretty sure mine is the 6300 series.

The kit is complete. It even comes with a new 12v distribution board that has the charge wizard built in.

Chris Bryant wrote:

Bobbo wrote:
I replaced the MagnaJunk 7345 in my old Winnebago with a PD4655V from Best Converters years ago. I sold my Winnebago last month and bought an Airstream. The Airstream comes with a Parallax (aka MagnaJunk) 8355 converter. It will be delivered next week, and I have a brand spanking new PD4655V from Best Converters sitting in the garage even as we type. The 8355 will never even be plugged in at this house.

YMMV

Umm- you do know that the 8300 series has the option of temperature corrected 4 stage charging- something the PD doesn't offer?

The 6300 and 7300 series are not good, but the 8300 series is different.

No. Please educate me. I am not above returning the PD4655V. The Parallax website has nothing on this.