high-voltage mppt controllers?

MPPT Controllers are more expensive than the PWM controllers. But the larger panels cost less/watt and take less space/watt.

The Morningstar MPPT 45 will handle your panels provided your VOC in series is less than 150V which they likely are. Parallel no VOC issue. The cost is about $400+. The MPPT 60 will handle 800W at about $500+.

BTW You'll want to install a temp probe which may not be included in the price ($30). You may also want a display panel about $100.

What panels are you considering? The 65"x39" panels are available in 250-270W for $200. S&H is expensive.

X2 CA Traveler

That's the first time I've seen the 'cell count' in a panel rating. Is that just a confusing way of saying 'voltage'?

Hi Gordon,

If you keep the wattage down to 500 the Rogue 3048 is quite an amazing piece of technology. It might be, that with a fixed install, a pair of 260 watt panels would rarely get over that number. It features a battery temperature probe, battery voltage sense wires, and (I think) does diversion loads as well.

Over 500 watts, and under 800, I'd go with the Tristar 60 amp MPPT unit. This is actually three 20 amp controllers piggy backed together. As solar harvest rises, first one section runs, then another is added. This allows it to run more efficiently, wasting less on overhead. The only lack on the MPPT unit is no diversion load.

Both of these units easily connect to a laptop so that their parameters can be tweaked, for items such as voltage set points.

The $102 Eco-Worthy MPPT 20a controller is available to run one 24v panel up to about 250w. (controller limit is 42Voc so only one panel at 37 or so Voc)

So you can run two panels at 250w each for 500w and put one controller to each panel with both controllers going to the same battery bank.

That is just as good as having one giant controller on the battery bank, but now your cost is $204 instead of kazillions for the giant controller.

Some members here have the Eco-Worthy (including me) and have proven they do work, so it is not a POS cheapo risky thing. :)

GordonThree wrote:
Any other options?

Morningstar
Xantrex
Midnight Solar

http://www.solarblvd.com/Charge-Controllers-MPPT-Charge-Controllers/c6_46/index.html

I have the morningstar 60 amp but you probably just need the 45 for the two panels.

The Outback controllers are excellent. I've never had any trouble out of any I've installed. The Xantrex XW 60 amp unit is very similar and also good. It has a larger heat sink and no fan. It is usually a bit less expensive than the Outback 60 amp.
MidNite Solar makes some nice units but they're probably more than the Outback. The Morningstar is probably the cheapest.
My preference would be Outback, that's what's in my own house. Do you have plans of adding a nice large inverter/charger to your rig? If so, and you use the Outback FX28212M, you can use the same MATE (remote display/control pad) for the inverter, charge controller, and battery monitor.

I will study up on the Morningstar products - thanks for the suggestion.

Midnight looks nice but like the Outback, it's too much controller for my small trailer, and my wallet :)

I have not decided on which panels yet, so many places to buy from. Watts per square inch make the big ones appealing. They seem to have some technology advantages too, like extra bypass diodes (3 to 6 is what I'm seeing), versus 1 or even none for the small panels.

The idea of using multiple inexpensive controllers is interesting - do they network? I can see bulk charge working fine, but voltage dependent absorb / float modes, won't they sense each others voltage and flip/flop on and off?