Pulled the trigger!

I have been using solar on 3 RV's over a 14 year period.
Here are my observations and recommendations.
Jatrax is correct, use a monitor which actually measures the current in and out of the batteries.
6V deep cycle batteries work best, standard lead acid are fine and cost effective. You must add water about every 2 months. If you can't do that, pay the extra for AGM. They offer no more benefit for capacity or life. My Trojan T-105 batteries that came with my 2012 PC are still working fine, but I NEVER go less than 50% charge as monitored with my Trimetric.
I had PC install all the parts except the arrays and had them move the antenna so no shadowing of arrays where I mounted on front.

I had them put the Trimeric where I could read it near awning switch.

My charge controller is mounted near batteries, nothing to read out. But I like my EMS control down low so when I plug my power in I can read from outside of my RV when I open the door.

Here is what my wiring system looks like with EMS and solar installed.

Mine are probably not better at all Ron.  You have the golf cart batteries I was talking about.  I was not aware they were available as AGM, but likely that is the best combination of 'deep cycle", ease of maintenance and cost you are going to get.  I checked some current pricing (which is all over the map so these are just quick averages).  Looks like around $129 each for regular GC2 and $199 to $225 for the AGM version of GC2.  AmpHours run around 225 for the regular and 230 to 250 for the AGM.  Many people report $99 GC2 batteries at Costco when they run a sale.

The regular flooded batteries provide about the same power but at a lower cost.  The AGM versions have the maintenance free advantage and slightly higher AmpHours.  Cost per amphour clearly goes to flooded, but for many (myself included) the maintenance free part makes the AGM worth the extra cost.

Note that my somewhat smaller AGM batteries run to 205 AmpHours.  The pair result in a 205 AmpHour battery pack @12 volts with 100 AmpHours usable allowing for a maximum discharge of 50%.

Did you have to make any modifications to your battery tray to allow yours to fit?  As I understand it the GC2 is a bit taller than the regular battery used by Phoenix.

Mine are probably not better at all Ron.  You have the golf cart batteries I was talking about.  I was not aware they were available as AGM, but likely that is the best combination of 'deep cycle", ease of maintenance and cost you are going to get.  I checked some current pricing (which is all over the map so these are just quick averages).  Looks like around $129 each for regular GC2 and $199 to $225 for the AGM version of GC2.  AmpHours run around 225 for the regular and 230 to 250 for the AGM.  Many people report $99 GC2 batteries at Costco when they run a sale.

The regular flooded batteries provide about the same power but at a lower cost.  The AGM versions have the maintenance free advantage and slightly higher AmpHours.  Cost per amphour clearly goes to flooded, but for many (myself included) the maintenance free part makes the AGM worth the extra cost.

Note that my somewhat smaller AGM batteries run to 205 AmpHours.  The pair result in a 205 AmpHour battery pack @12 volts with 100 AmpHours usable allowing for a maximum discharge of 50%.

Did you have to make any modifications to your battery tray to allow yours to fit?  As I understand it the GC2 is a bit taller than the regular battery used by Phoenix.

Hi jatrax,

Thanks for the details.

About my battery tray......
My rig is a 2007 model year.  The batteries of the period were two flooded 12V batteries hooked up in parallel.  6V batteries whether flooded or AGM are much taller than 12V and their foot print is also different.  To make room for the taller Sam's Club Duracell GC2 AGM batteries, I had to ditch the slide-out battery tray and install a steel plate directly onto the compartment framing.  I then cradled the batteries with bolt-on "L" brackets so they would not move around.  Removing the front "L" bracket allows the batteries to slide out from the compartment.  My 6V setup would be horrific to check flooded battery fluid levels, hence the decision to go with AGM technology.  Doing so, I had to change my Tripp-Lite inverter from the "flooded technology" setting to the "AGM technology" setting by relocating a jumper from one position to another inside Tripp-Lite inverter.  That took just a few seconds once I learned what to do.

I wrote a post about the 12V to 6V battery conversion project with pictures HERE.
Pictures of my original battery compartment before the modification can be reviewed HERE when I added a 1/4" thick rubber shield between the battery compartment and rear tires.  Back in those days the batteries had no protection from rear tire splash.

Ron Dittmer

Thanks Ron!  I am good with my batteries for a few years, 4 to 5 I hope, but I definitely will go with the ones you have when I replace them assuming they will fit.  I'm not sure I want to give up the sliding battery tray.

I carry a Viair Tire Inflator and that requires using jumper style cables directly on the battery.  So having the tray slide out makes attaching the cables a lot easier.  Would be nice to have a few extra AmpHours though.

But maybe in 5 years they will have Lithium or some other technology to the point that it will be competitive with lead acid.

Since 2012 the sliding tray that PC supplies is designed to hold two GC2 or two T-105  deep cycle batteries. The 2006 2551 had only one battery on their sliding tray.

jatrax,

Phoenix had to have increased the vertical height within the battery compartment in recent years to accommodate taller 6V batteries, yet retaining the slide out battery tray.  I wonder how they achieved it?  My 12V battery tray shown below has a height differential of exactly 1".  Did Phoenix reduce the height of the 6V tray to something like 1/4"?  Even if they did, it's not enough by itself.  I wonder where they got the rest of the room.  The bottom-most part of my battery compartment framing hangs below the battery door by exactly 2-1/8".  If yours is lower, that could be where they got the extra height from.

Sorry Tall Guy for going off topic.

Ron Dittmer

No worries for going off topic Ron, if I can learn something I'm all for it even if it's "off topic". 

Thanks to all for the input, I've made several notes to discuss with Earl.  Keelhauler, where did you get your solar panels from?  Did you install them yourself?  Were the Phoenix offerings not what you wanted?  Would Phoenix have installed them for you?

Next Thursday we're leaving for our last vacation with the truck we affectionately call "The Big Dude".  Gonna be kinda bittersweet, we've had a lot of good times in it but are looking forward to our upgrade!

Thanks again!
Gary

Thanks to all for the input, I've made several notes to discuss with Earl.  Keelhauler, where did you get your solar panels from?  Did you install them yourself?  Were the Phoenix offerings not what you wanted?  Would Phoenix have installed them for you?

In 2012 PC did not offer solar panels.

I bought everything from https://www.altestore.com/store/
Kyocera Arrays.
PC installed all the parts, including wiring but I installed the arrays.  They will not do that now, I heard.

Arrays were simple just bolt down 2-1" aluminum angles/per array to roof using self drilling SS screws, Lots of Di-Cor.
 The angle on the panel then bolts to the angle that was bolted to roof.
On all 3 RV's never had a leak.

Phoenix had to have increased the vertical height within the battery compartment in recent years to accommodate taller 6V batteries

Ron, I'm not sure but my battery tray looks identical to yours with the same 1" of clearance.  I actually measured about 7/8" at the edge but it's 1" in the center where you measured.  Maybe it hangs a bit lower?  Not sure.

I also checked my batteries and they are GC2 size.  They are marked T-105 but it appears that is the Trojan number but the dimensions are exactly the same as what is listed for the Duracell ones you have.  So we both have identical size batteries.  Your Duracell is rated at 230 AmpHours and my Trojans are rated at 225 per the spec sheets.  So mighty darn close.

The batteries are 10.5" deep and the battery tray is about 13" deep so a slightly larger battery could fit.  There is a GC12 that fits those dimensions exactly but when pushing the battery slide home I'm not sure whether the GC12's would hit into the wiring on the rear bulkhead.  Something to check someday.

jatrax,

I know what you mean about crushing the wires in back.  I have a decent gap behind my 6V batteries which I utilize to get the cables well dressed, not kinked.

Interesting that I had to sacrifice my 12V battery tray to get enough 6V height clearance, but others with 6V batteries, it's all good as-is.  There must be something we are over-looking.  Oh well.

Ron Dittmer

You are overlooking the fact that PC just lowered the whole tray to give more vertical height.
I convinced them in 2012 that 6V batteries were better, they started to put them in all units. Up to that time it was an option whether or not you wanted 6V batteries.
So the change is ground clearance. The tray is closer to the ground.

You are overlooking the fact that PC just lowered the whole tray to give more vertical height.
I convinced them in 2012 that 6V batteries were better, they started to put them in all units. Up to that time it was an option whether or not you wanted 6V batteries.
So the change is ground clearance. The tray is closer to the ground.

That is what I thought they had to do to make it work.

The bottom of my battery tray framing measure 2-1/8" below the battery door.  Does your framing hang lower?  Or did Phoenix change the door to cover more of the under-hang?

Here is my under-hang, picture not taken at the best angle to see the entire 2-1/8" under-hang.  What is seen is the steel plate battery compartment floor I added that rolls over the edge covering some of the framing.

Does your framing hang lower?  Or did Phoenix change the door to cover more of the under-hang?

Yes, No

I just talked to Earl and upgraded to the max-air fans (2) and added the Trimetric TM-2030 and SC 2030.  Earl said there wouldn't be an issue with shadowing with the d-side external light.  Our original build which I didn't detail included the insulated windows and AGM batteries. 

We've decided to store it outside on either a cement or limestone pad for a couple years and then probably build an open ended carport type shelter over it as time and $$$ allow.

I've gleaned a lot by reading this forum for the last couple of years, thanks for everyone's help!  Next comes the waiting time and then the first hand learning curve.

Gary

I know what you mean about crushing the wires in back.  I have a decent gap behind my 6V batteries which I utilize to get the cables well dressed, not kinked.

Short side track; the first thing I did upon arriving back at home with the new buggy was crawl underneath armed with a bunch of cable ties and electrical tape. Dangling/floppy wires, battery cables, chafe points, and other potential problems were secured or wrapped. The wiring set for the black/gray water valves was routed through a pretty jagged-edged hole in the fiberglass. I slit a piece of plastic tubing and created a grommet for the hole. Chafing, whether on dock lines, electric lines, or body parts, is never good!

Steve