Parallax 8355 - Keeper, Junk, or Something Else?

[dznf0g]

Originally Posted by ckottum

That would work too, but then it's up to the batteries and solar system to run the 12vdc equipment. In our case where we are traveling in this rig 7 months a year, the daily discharging of the batteries would take a toll on them.

My suggestion to set the Battery Switch to "STORE" to isolate the batteries from the converter (when on external power) is primarily for those who may want an interim solution for the parallax until they upgrade, or for those who just want to get along with it as we do.

cheryl

Boy, your store switch must be wired completely differently than mine. When mine is in store, the converter is still connected to the batteries, but the ENTIRE 12V system (all lights, pump,fans, etc.) are shut down and isolated from the batts and the converter.

[lewster]

Originally Posted by dznf0g

Boy, your store switch must be wired completely differently than mine. When mine is in store, the converter is still connected to the batteries, but the ENTIRE 12V system (all lights, pump,fans, etc.) are shut down and isolated from the batts and the converter.

Really????

In all of the electrical upgrades that I have done, the Use/Store switch simply disconnects the converter from the positive bus bar, which is also fed from the battery positive terminal.

With the switch in 'store', and the positive bus bar and hence the batteries are isolated from the converter. It will simply send a constant 13.6VDC into the fuse block that provides power to ALL of your DC circuits (assuming, of course, that it's a Parallax. 3-stage converters will not 'see' a battery and will also provide this constant voltage at whatever their output is set to.

I have lots of folks in FL that permanently attach their rigs to their concrete pads with hurricane straps, leaving the RVs for the summer when they head back north. I have removed many batteries, as they are not needed to provide 12VDC for the RVs UNLESS they are on the road, which they will probably never see again.

In this instance, the converters only provide the DC voltage for all of the interior DC loads and control voltage and do not perform any battery charging.........'cause they ain't there no more!!!

[dznf0g]

Nope, Lew. The Classics form my era have a manual store switch between the positive buss bar and the 12V distribution fuse block.

[lewster]

Originally Posted by dznf0g

Nope, Lew. The Classics form my era have a manual store switch between the positive buss bar and the 12V distribution fuse block.

Pretty easy to re-wire!

[acstokes]

Nope, Lew. The Classics form my era have a manual store switch between the positive buss bar and the 12V distribution fuse block.

My 2009 Classic is also wired this way.

[dznf0g]

Here is a pic of the inside of my electrical center door, showing the backside of the store switch. the single cable to the switch originates at the positive buss bar.



Here is the Buss bar (with breakers). 2 red wires (one from each batt) and one from the old Parallax (at top); and one red (at bottom) going to store switch



The only original routing that was changed was to move the Propane sensor/alarm downstream from the store switch so it's parasitic drain would not be present when in store.

[dznf0g]

Lew, I don't want it re-wired. I think there are different definitions of "store". Store to me means "batts installed, unit in storage with no 120V power, and as little parasitic drain as possible".

If I have 120V power available (as I will soon as my pad is poured at home) I would just unplug the converter from the wall to "isolate" the batts and 12V system from the converter.

[acstokes]

Lew, I don't want it re-wired. I think there are different definitions of "store". Store to me means "batts installed, unit in storage with no power, and as little parisitic drain as possible.

I agree. I like mine wired this way.

[dznf0g]

In addition, it is my understanding that the Parallax is not a steady "clean" 12V output and needs the batts to act as a electrical "stabilizer" or "sink" (pardon my current brain fart on the proper term) and shouldn't be powering the 12V system alone....unlike a more quality converter.

[lewster]

Originally Posted by dznf0g

Lew, I don't want it re-wired. I think there are different definitions of "store". Store to me means "batts installed, unit in storage with no 120V power, and as little parasitic drain as possible".

If I have 120V power available (as I will soon as my pad is poured at home) I would just unplug the converter from the wall to "isolate" the batts and 12V system from the converter.

I'm with you!!!!

I have installed a bunch of total battery disconnect switches that interrupt the main DC line from the batteries to the bus bar........ operates just like yours!!!!! When the switch is off......the coach is shut down!!!

I have no idea why anything other than the Classic has the electronic/solenoid version that still has parasitic loads connected directly to the bus bar and only isolates the battery from the bus bar??

Yours is better!!

[dznf0g]

Agree, Lew, I have never understood that electric switch fiasco...other than the desire to have it on the wall rather than down low at the electrical center. But I use it...maybe 3 or 4 times a year...so.....

[Wayne&Sam]

Originally Posted by StillRod

I say flaky because, in comparison to our 2012 19 footer, the battery use curve turns south dramatically faster. Whereas we consistently went three nights boondocking, we are lucky to get through two nights in the 25 with seemingly similar usage of lights, water pump, fans, etc.

It makes me wonder about greater ambient loads from the charger fan, the thermistor controlled reefer fan, and the inverter on the one hand and about the charger's workings on the other.

The batteries themselves were brand new as the trailer had been built only three weeks before we took delivery. Maybe we cooked them, which I accept as possible, but I hope not. Our intent is to keep this trailer a good while, and upgrade where appropriate...perhaps starting with the Parallax?

I noticed the same thing between my 2007 20' and the 2014 25'. The contributing things I've found are:

25' has a subwoofer that is always on if the radio in standby. Now I make sure the radio is fully off.

Inadvertently leaving the TV antenna booster on.

No off switch for the refrigerator fan.

Not sure but I think the water pump with its soft start uses more juice too.

[Burnside Bob]

My 2009 FC 25' FB has a mechanical battery disconnect switch on the battery box. As a number of posters seem to have newer trailers without a mechanical disconnect switch, was this mechanical battery disconnect switch an option??

My trailer does have the Parallax 8355 converter. Since getting the trailer end of Feb we have had it plugged into shore power with batteries connected in. Today, electrolyte levels appeared normal and there was no evidence of boiling or venting. Voltage, batteries disconnected, was 13.02 volts and, connected to converter, 13.63 volts.

According to the date code, these batteries were new August, 2013. We know battery voltage was near zero when we picked the trailer up, so we are not expecting them to have a long life.

Adviseable to replace converter and batteries at same time??

[idroba]

Originally Posted by Burnside Bob

Adviseable to replace converter and batteries at same time??

When you find that your batteries need replacing, it would be a good idea to do the converter/charger too.

If your batteries were near zero charge when you picked the rig up and so far it has worked for you, that is the batteries, you may have lucked out and they did not sulphate or become too damaged. That is pretty rare though. If you boondock and find the battery capacity poor, you will know it is time to replace them.

[dznf0g]

Originally Posted by Burnside Bob

My 2009 FC 25' FB has a mechanical battery disconnect switch on the battery box. As a number of posters seem to have newer trailers without a mechanical disconnect switch, was this mechanical battery disconnect switch an option??

My trailer does have the Parallax 8355 converter. Since getting the trailer end of Feb we have had it plugged into shore power with batteries connected in. Today, electrolyte levels appeared normal and there was no evidence of boiling or venting. Voltage, batteries disconnected, was 13.02 volts and, connected to converter, 13.63 volts.

According to the date code, these batteries were new August, 2013. We know battery voltage was near zero when we picked the trailer up, so we are not expecting them to have a long life.

Adviseable to replace converter and batteries at same time??

The mechanical disconnect was not an option, and some consider the electric store switch an improvement. Based on what I have read here, I don't, and am glad I have an old fashioned mechanical store switch.

[StillRod]

Good discussion. I've gleaned several Take Aways thus far:
- upgrade to a multistage charger
- tend batteries more vigilantly than I otherwise have
-- consider AGM batteries for their higher capacity and better behavior
- rewire battery disconnect, placing it further upstream to eliminate parasitic drains
- go back to college to study electrical engineering

Do I have that about right?
Any recommendations for a specific brand or model of charger?

Thanks,

Rod

[Silver.Sanctuary]

Originally Posted by wulfraat

Junk that thing and get a Progressive Dynamics converter. The Parallax unit cooks batteries. Ask me how I know.

I followed all the threads and got a Progressive Dynamics replacement. I have to say the installation was pretty easy and no adjustments had to be made to the circuit breaker panel or other items.

[idroba]

Originally Posted by StillRod

Good discussion. I've gleaned several Take Aways thus far:
- upgrade to a multistage charger
- tend batteries more vigilantly than I otherwise have
-- consider AGM batteries for their higher capacity and better behavior
- rewire battery disconnect, placing it further upstream to eliminate parasitic drains
- go back to college to study electrical engineering

Do I have that about right?
Any recommendations for a specific brand or model of charger?

Thanks,

Rod

You get an A for thread reading skills. The degree in EE will unfortunately not earn you practical skills, mainly theory on which to base them. Finding the practical side is the most difficult part of electrical things.

The Progressive Dynamics line of independent converter/chargers (92xx series) and their line of built in charger replacement units (46xx) is a good one. There are several others.

[lsbrodsky]

In case you have not seen it, Randy at Bestconverter.com is the place to go for this kind of question and equipment. Even better, he is in your neck of the woods.

Larry

[2012FB]

One of the first things I did on our New 2012 25FB was replace the incorrectly engineered change over switch (small relay) that left us with out any power the first two outings till I realized how badly underrated the factory change over switch was.

While I had things torn apart I replaced the bottom of the line converter with a new Iota DLS55MW/IQ4. A very good and easy upgrade.

The black box on the top right was the new 30A change over switch "contactor" assembly. The Iota I mounted on the wall on the left. I don't think I ever heard the fan come on.

I plan on upgrading our new 2015 Bunk in the next month or so. Currently I keep the batteries disconnected in storage and use a battery minder to keep them in good shape.