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- Morningstar documents their MPPT45 controller for overpanel and derate to 45A plus it's stated solar input is 600W. With tilted panels you might occasionally reach the limits for a short period of time. With flat panels not likely. No need to use 13V as the controller will ramp up discharged batteries to 14.8V for bulk charging.
- If all four panels were in connected in parallel, it would give me 544w @ 24VDC (just under 23A). Running this one feed to the inputs of three 20A controllers should balance out between the controllers. Am I missing something in this type of setup?
Bedlam wrote:
jrnymn7 wrote:
300w input = 300w output
If your bank is at 50% soc, the controller will start out at about 23 amps @ 13 volts. Even at a 14.4v setpoint, the controller will still be maxxed out. So, no, two eco-worthy 20 ampers will not do.
Couldn't the output of all four panels be parallel connected and three of these 20A controllers run with parallel inputs?
This would put the cost closer to $300 verses $450 for a 60A single unit.
I don't ever expect 100% efficiency and will be happy with half. I live in an area that is overcast more than sun.
In that case, two 20a eco-worthy's would do, provided you don't get some good sunshine. (Not something I would want to have to worry about). But I am curious how you plan to wire four panels in parallel to three controllers?smkettner wrote:
jrnymn7 wrote:
No need to derate a Morningstar. It can run at 45 amps all day and still handle cloud edge effects or anything else.
"BTW who has 150 watt 24 volt panels?"
SMK, That was my first thought, but apparently there are quite a few to choose from.
A 45a controller seems a little on the low side?
600w in = 600w out, 600w / 13v = 46a output + 20% = 55a
(37.5a output + 20% = 45a)
Truth is I am lucky to see 45 amps out of my 675 watts flat on the roof. Worst case the Morningstar will just limit amps to 45 but no harm to the controller. Most you lose is an amp or two for a few minutes.
And the 600 is now down to 544 watts so even less need for more than 45 amps. Actually more approaching need for just 30 amps.
As long as the controller can handle it, I agree. I'm just a little leary about maxing out charge controllers. But if in your experience, the Morningstar can handle being (near) maxed out, then certainly.jrnymn7 wrote:
No need to derate a Morningstar. It can run at 45 amps all day and still handle cloud edge effects or anything else.
"BTW who has 150 watt 24 volt panels?"
SMK, That was my first thought, but apparently there are quite a few to choose from.
A 45a controller seems a little on the low side?
600w in = 600w out, 600w / 13v = 46a output + 20% = 55a
(37.5a output + 20% = 45a)
Truth is I am lucky to see 45 amps out of my 675 watts flat on the roof. Worst case the Morningstar will just limit amps to 45 but no harm to the controller. Most you lose is an amp or two for a few minutes.
And the 600 is now down to 544 watts so even less need for more than 45 amps. Actually more approaching need for just 30 amps.- The Eco-Worthy is a good controller for a single 24v panel but it has a limit of 42V Voc total for all panels on it. So using it with two 12v panels in series at 22voc each is too much.
The Tracer MPPT has a Voc limit of 100v and you can get them in higher sizes than just 20amp too. They cost a little more than the Eco-W at about $140. It has a fixed charging profile, not adjustable. It gets the batts to 14.6v, holds that for two hours, and then drops to 13.8v till dark. This charging profile worked well for me but YMMV. (Same one as in the LandStar I had)
Yes you can parallel controllers, no problem . JiminDenver has three Eco-Ws but on three 24v panels so each controller is under that 42v Voc limit. jrnymn7 wrote:
300w input = 300w output
If your bank is at 50% soc, the controller will start out at about 23 amps @ 13 volts. Even at a 14.4v setpoint, the controller will still be maxxed out. So, no, two eco-worthy 20 ampers will not do.
Couldn't the output of all four panels be parallel connected and three of these 20A controllers run with parallel inputs?
This would put the cost closer to $300 verses $450 for a 60A single unit.
I don't ever expect 100% efficiency and will be happy with half. I live in an area that is overcast more than sun.Bedlam wrote:
These are going on the metal roof of an enclosed trailer, so I have more flexibility in mounting or removing compared to TPO, fiberglass or rubber surfaces.
In that case they may be good, but you may also have an issue if the roof is rounded. If you were parked N/S, half the panels would be tilted away from the sun, morning and evening. If parked E/W, half would be tilted away almost the entire day (in summer), and the entire day (in winter).- These are going on the metal roof of an enclosed trailer, so I have more flexibility in mounting or removing compared to TPO, fiberglass or rubber surfaces.
Bedlam wrote:
I was thinking about ganging two of these controllers together (one per pair of panels) for about $205 total cost:
http://www.eco-worthy.com/catalog/mppt-solar-charge-controller-free-shipping-p-182.html
300w input = 300w output
If your bank is at 50% soc, the controller will start out at about 23 amps @ 13 volts. Even at a 14.4v setpoint, the controller will still be maxxed out. So, no, two eco-worthy 20 ampers will not do.
