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+--- Thread: Looking for (not tall) charge controller for 540 watts (/thread-824.html)
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Looking for (not tall) charge controller for 540 watts - TedOnWalkabout - 01-01-2018
Okey dokey, folks I'll start with Happy New Year!
With that out of the way, I am looking for some help in buying a new charge controller for my trailer. I have 3 x180 watt panels. But between the vents, hoods and antenna, there will be shade on at least one of the panels except at high noon (or at the right time of year or the solar orientation of the trailer). I like the Blue Sky 30amp controller that I have on the van, but it's not big enough for the 540 watts. I don't have a large (tall is the problem) space in which to put the controller close to the batteries, so I was looking at the Victron units. But they irritatingly require a Bluetooth dongle or a separate display unit to adjust the settings.
So, recommendations for a squat charge controller? Is the Victron good enough? Thank you,
Ted
RE: Looking for (not tall) charge controller for 540 watts - TedOnWalkabout - 01-01-2018
Uh, just measured. I have max 9 inches high where I will mount the charge controller.
Ted
RE: Looking for (not tall) charge controller for 540 watts - GotSmart - 01-01-2018
I wish I had a recommendation for you.
RE: Looking for (not tall) charge controller for 540 watts - frater secessus - 01-01-2018
Spitballing:
- I think most controllers are tall to enable passive cooling; updraft of warm air pulls cool air in after it.
- Maybe wire up two panels together into the existing controller, and mount a 15-20A controller somewhere else for the third one? This would allow you to keep the controller you like while increasing shade tolerance.
- If you'll be at the RTR I bet someone will have a BT dongle you could borrow for setup of a Victron.
- You could probably mount a tall controller sideways without overheating if you blew air down the heatsink fins.
- If you had 2 batteries instead of 3, it might be cheapest to run them serial as 24v; that'd be well under the rating of your existing 30A controller. Then downconvert for house loads. A PITA, but maybe cheaper.
- The Morningstar prostar 40A mppt is about 8" tall and tolerant of overpaneling.
- The Victron 100/50 is less than 8" tall and would handle the panels. I think victron advises against overpaneling, so I went up to 50 on that.
RE: Looking for (not tall) charge controller for 540 watts - Scott7022 - 01-01-2018
Good advice. Doesn't the dongle also allow you to monitor what the unit is doing while it is doing it? Might be handy to have... Just a secondary point of consideration.
RE: Looking for (not tall) charge controller for 540 watts - TedOnWalkabout - 01-03-2018
Okay, so I'm watching a contentious thread on the Dark Side about the Renogy Eclipse panels (you go girl, Cammalu!). I'm still thinking about the Victron charge controller(s?). Now another possibility that hadn't occurred to me: except at high noon, in all likelihood, one panel will be partially shaded from all the crap on my roof. The cost for three Victron 75/15s is about the same as the cost for the one 100/50. With the surety of at last one of the panels partially shaded, is it better to go with a charge controller to each panel? The only added cost will be some wire and cheap hardware. I have a wide horizontal area big enough for several controllers.
It's coming down to decision time. I won't be going to the RTR-the thought of that many people in Quartzite gives me the heebie-jeebies. So no help from that direction. And i dont know enough to trust the advice from the Other Place.
Ted
RE: Looking for (not tall) charge controller for 540 watts - GotSmart - 01-03-2018
If you plan for the worst situation, you will usually be disappointed.
I have found that is is not wise to make the magic smoke gods tempted to remove their blessings.
RE: Looking for (not tall) charge controller for 540 watts - Blacktank - 01-04-2018
(01-03-2018, 09:18 PM)GotSmart Wrote: If you plan for the worst situation, you will usually be disappointed.
I have found that is is not wise to make the magic smoke gods tempted to remove their blessings.
o.k. Confucius do you have something for us not pondering the meaning of life,like? i dont know? WHAT TYPE OF CONTROLLER SHE SHOULD GET
btw ted i got the letter
RE: Looking for (not tall) charge controller for 540 watts - GotSmart - 01-04-2018
(01-04-2018, 01:21 AM)The Gary Wrote:(01-03-2018, 09:18 PM)GotSmart Wrote: If you plan for the worst situation, you will usually be disappointed.
I have found that is is not wise to make the magic smoke gods tempted to remove their blessings.
o.k. Confucius do you have something for us not pondering the meaning of life,like? i dont know? WHAT TYPE OF CONTROLLER SHE SHOULD GET
btw ted i got the letter
Oh Grasshopper
You must contemplate what makes magic smoke gods happy. MORE POWER. There will come a day at a high elevation when the sun will shine brightly, the wind will be gentle, and the controller will be overwhelmed.
Walkabout, trust your knowledge. You have a unique system and unless Stearnwake speaks up use your best judgment.
By the way. You have found the holy grail of battery sources.
RE: Looking for (not tall) charge controller for 540 watts - sternwake - 01-04-2018
You could split your existing panels into two arrays with two charge controllers on teh same battery. If their absorption voltages are set the same then they should work fine together in parallel on the same battery bank up through absorption, and at float one does not require the full output of the panels anyway.
That way partial shading does not limit the whole array, only half of it.
Also while it is best to keep solar controller close to batteries, for a shorter circuit, well that can be sidetracked with thicker cabling to offset the voltage drop of greater distance between controller and battery.
I know the controller inputs can only accept "X?" AWG wire size, but there are ways to get around this and get fatter cabling into the controller receptacles.
Dont fear the longer circuit between charge controllers and batteries. Ideal is short an fat circuit, but one can try and be more efficient elsewhere.