Solar In The Desert

Ducky's Dad

Explorer
Received confirmation from Ctek that the D250SA will not interfere with the alternator charging the starter battery at full amperage. I looked at the Redarc site last night and will call them later, but their unit is physically pretty large so need to figure out where to mount it. Looking again at the the Morningstar Sunsaver Duo, but my reading of their user manual indicates that absorption charge is at 14.1V for sealed batteries, which seems far from ideal for AGMs. Need to read the manual in more detail.
 

Ducky's Dad

Explorer
Just got off the phone with Morningstar tech and the Sunsaver Duo shuts down at 113F controller temp, regardless of battery temp. So, in the cab on a hot day with the A/C running, the solar will work but will will shut down sometime after the truck is parked. Looks like the search continues. Need to call Redarc.
 

john61ct

Adventurer
Did you check with Victron?

May also want to consider low-current PC-style fans controlled by an adjustable thermostat.

And a big awning / tarp for some shade.

Why do you want to be in that kind of heat again?
 

DiploStrat

Expedition Leader
Received confirmation from Ctek that the D250SA will not interfere with the alternator charging the starter battery at full amperage.
[/OUOTE]

NONE of these units will interfere with the alternator charging the starter battery, we are talking about the maximum output to the CAMPER battery. With the D250S it is 20A, with the REDARC, it is 40A. Sterling makes a few units that go even higher.

All B2B are logically (if not always physically, see luthj's comments) attached between the starter battery and the camper (house) battery. Thus the train is alternator>starter battery> camper battery.

Indeed, the selling point for a B2B is that it does not interfere with the factory wiring in any way. (It just tricks the alternator into thinking that the starter battery is discharged.)

I looked at the Redarc site last night and will call them later, but their unit is physically pretty large so need to figure out where to mount it.

The measurements should be available on the respective websites. The REDARC is a lot smaller than the Sterling A2B that I used.
The REDARC is shorter and lower, but wider than the CETEK. The CETEK may be even taller as the connections are on top.


...l indicates that absorption charge is at 14.1V for sealed batteries, which seems far from ideal for AGMs. Need to read the manual in more detail.

"Sealed" can mean gel, AGM, or VRFLA. Don't go by the title, go by the absorb voltage that you want. For most AGM that is 14.4v or a bit higher at 70F.
 
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Ducky's Dad

Explorer
Why do you want to be in that kind of heat again?

I must be dumber than I look, but I'm not alone. We have eleven guys going on the next trip, end of August/Labor Day weekend.
 

Ducky's Dad

Explorer
I called Redarc today, but their North Carolina number rings into central Australia. May not be a good sign for inventory in North America, or for tech support calls down the road. Left a message but don't expect a return call until next week.

Have not been able to find any decent capacity true deep cycle AGMs in 6V or 12V that will fit the Grp 34 boxes for the house batteries. Would like to go with all one brand/same charge profile for starter and house, so looks like it's between Odyssey and Northstar. Leaning toward Northstar. I have looked at deep cycle AGMs from Lifeline/Concorde, Rolls/Surette, Trojan, MasterVolt. Grp 24 and 27 are too tall to fit. Any other deep cycle lines I should look at?
 

DiploStrat

Expedition Leader
At the risk of being even more of a REDARC phanboi than I already am, this is actually good news. The date line and time zones are sometimes annoying, but you are talking directly with the engineers who built this trash, not some kid with a script. "Now, are you sure you connected the red wire ..."

My truck features a "Twisted Sister" charging system and the folks at REDARC really helped to make it happen, both by phone and e-mail. (E-mail is more manageable, go to bed with a question, wake up with an answer.)

Full disclosure: Charlie Sterling Jr. has been equally helpful.


 

john61ct

Adventurer
Have not been able to find any decent capacity true deep cycle AGMs in 6V or 12V that will fit the Grp 34 boxes for the house batteries. Would like to go with all one brand/same charge profile for starter and house, so looks like it's between Odyssey and Northstar. Leaning toward Northstar. I have looked at deep cycle AGMs from Lifeline/Concorde, Rolls/Surette, Trojan, MasterVolt. Grp 24 and 27 are too tall to fit. Any other deep cycle lines I should look at?
Because that's a Starter batt size, not for deep cycling, why was it selected?

Best to change to G31 or 27 or for FLA EGC2 even better, box should fit the batts you want not v/v.

Otherwise go with Odyssey or Northstars, not sure if Lifeline makes G34, and accept replacing more frequwntlt.
 

DiploStrat

Expedition Leader
...
Best to change to G31 or 27 or for FLA EGC2 even better, box should fit the batts you want not v/v.

This is good advice. Or, if you think lithium is in your future, take the plunge and relocate the battery box into the heated part of your vehicle. Might be worth it if you can get by with a lithium bank that is physically smaller. Maybe use the current battery box site to store something that does not need to be inside?

A random thought.
 

Ducky's Dad

Explorer
Because that's a Starter batt size, not for deep cycling, why was it selected?

Went with 34s ten years ago because that was what would easily fit the available space under the truck. Needed to clear skid plates and still be able to tuck batteries up as high as possible to clear trail obstructions. Unwilling to give up any cab or bed space for batteries, and zero space available under the hood. Battery boxes are two separate welded steel units bolted to the frame rails. Fabbing new boxes would still not allow me to use Grp 24 or 27 batteries because there is just not enough room under there. No way to fit Grp 31s under there, either. Can't use FLA because batteries have to be mounted on their sides for clearance. Lifeline does not make a Grp 34 or anything even close. If they did I would be done with this part of the project.
 

Ducky's Dad

Explorer
Anyone use Full River AGM deep cycles? Found them today while poking around. Designed in US, manufactured offshore (China?). Capacities about same as Lifelines, longer warranty, about 2/3 the cost of Lifelines.
 

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