Do I need a new solar controller?

[Captain Bill]

Originally Posted by Jelani

I am having a similar problem, I have 3 160watt solar panels with an Mptt 100/30 Victron controller. However it is only putting out 25-28 watts on a sunny day for the last 7 days They were previously putting out upto 290watts. Checked each panel 21.5volts and getting +- 7amps which seems correct. I am wondering whether our controller is faulty. I have the Victron App but am reluctant to mess with any of the settings

I assume that you have checked all of the connections and they are all clean and tight. If so don't give up on the controller yet. As with most things these days solar charge controllers are controlled by a small computer and like most computers they occasionally go haywire and must be cold booted. This means removing all power, both form the panel side and battery side and allowing all of the capacitors in the circuit to discharge. Essentially the same as taking your battery out of your cellphone for 30 seconds and putting it back in. The capacitors in the controller are likely bigger than those in your phone so I would keep it disconnected for at least an hour. It's certainly worth a try before you trash the controller.

[Captain Bill]

Originally Posted by Kalimniosjohn

Stu, I did program the charge parameters to what I read was the proper volts for AGM batteries. I believe 14.6 absorption and 13.4 float. Can’t remember off the top of my head. Is there still more I can do?

You definitely want a shunt and an ammeter. Lifeline AGM batteries are considered fully charged when the amps flowing into the batteries reaches .5% of the battery amp/hr rating. For instance my 420 AH bank is considered fully charged when the amp reading is 2.1 amps at 14.4v at 77 degrees f. While the amps don't change, the voltage changes somewhat with battery temperature. Most solar controllers do not use this amp reading for controlling charge but use time at absorption voltage which is in fact a crappy way to do it. When one has a shunt/ammeter you adjust the absorption time so that it goes to float at your ideal charge amperage. On my bank it takes about 3.2 hrs to get to 2.1 amps charge. The default was 2 hrs which was undercharging my batteries.

[john61ct]

A clamp ammeter can be used to calibrate the termination point.

If you're going to install a shunt may as well put in a proper SoC battery monitor.

[Discovery 15797]

Originally Posted by Captain Bill

It looks like you won't have a shading problem when the boat is pointed north, but a bit of one when the boat is pointed south or east. If you are south of Peanut Island in WPB then the tide is probably controlling which way you are pointing and that will usually be pretty much north or south. It's probably not a terrible problem in the summer, but may limit your power gain in the winter,at least when the tide is going out during the middle of the day.

Unless one mounts the solar panels above mast height...there is always to potential for shading 1 or more panels.

I always recommend 1 controller per panel. It's a more expensive setup, but if you're really trying to optimize output it's the way to go.

[Captain Bill]

Originally Posted by Discovery 15797

Unless one mounts the solar panels above mast height...there is always to potential for shading 1 or more panels.

I always recommend 1 controller per panel. It's a more expensive setup, but if you're really trying to optimize output it's the way to go.

The OP's panel were mounted on a stern arch approximately 55 feet below the top of his mast which is mounted at about 60% of the overall length from the stern. West palm beach is about 24.6 degrees north latitude. The maximum length of the shadow between 1100 and 1300 local time between March 21 and Sept 21 is about 24.5 feet when the boat is facing south. The distance from the mast to the solar panels is about 30 feet. When the boat is facing north the shadow is no issue. In the ICW south of the inlet tidal current controls the direction the boat is facing except near slack tide. Any other time the boat is facing north or south. Hence my analysis that in the summer he won't have much of a shadow issue, but in the winter with longer shadows he will. His real shadow issue will come from his wind generator, not his mast.

[Kalimniosjohn]

Yes, captain Bill is correct. The panels don’t ever seem to get any shading from the mast but the wind generator does effect the panel closest to it. When I get the two new panels and the second controller the two panels on the port side will be on one controller and the two panels on the starboard side will be on the other. This way two panels on port will almost always be producing with no shadow issues.

With regards to time at absorption mode, this new victron seems to stay in absorption based on battery voltage at the beginning of its start cycle in the morning. At least that’s what it says when I go into the settings menu. It is currently set for a maximum allowance of 6 hours absorption and the last three days the amount of time in the absorption mode have all differed. Monday was two hours, Tuesday was 4 hours 15 minutes, and today was 3 hours 27 minutes.

[Captain Bill]

Originally Posted by Kalimniosjohn

Yes, captain Bill is correct. The panels don’t ever seem to get any shading from the mast but the wind generator does effect the panel closest to it. When I get the two new panels and the second controller the two panels on the port side will be on one controller and the two panels on the starboard side will be on the other. This way two panels on port will almost always be producing with no shadow issues.

With regards to time at absorption mode, this new victron seems to stay in absorption based on battery voltage at the beginning of its start cycle in the morning. At least that’s what it says when I go into the settings menu. It is currently set for a maximum allowance of 6 hours absorption and the last three days the amount of time in the absorption mode have all differed. Monday was two hours, Tuesday was 4 hours 15 minutes, and today was 3 hours 27 minutes.

Do you plan to stay on the hook in Palm Beach or are you planning to cruise? If you are planning to cruise the Bahamas or Caribbean then you might want to move your wind generator to the port side. With the prevailing wind being out of the east (NE-SE) you will have less shadowing issues, especially in the winter with the wind generator on the port side.

[Kalimniosjohn]

For now, staying in palm beach with trips to the Bahamas. We do plan to go cruising as soon as we have all the major mods Completed, and as soon as our cruising kitty reaches a comfortable level.

That is good info, I hadn’t even thought about the wind gen shading while in the Caribbean.

[GILow]

I might have missed it, but has anyone recommended a battery monitor yet?

An extremely useful device, I would almost say essential. The Solar Controllers are good, the OP has bought one of the best, but a monitor is still going to tell a lot more than the controllers.

After a while I stopped looking at my controllers, all I look at now is the monitor.

[GILow]

Originally Posted by Kalimniosjohn

...I have been so busy fixing and rebuilding everything else I just kind of hoped it would all work. Alas, there will be nothing that just WORKS, and I will have to start researching solar next...

This sounds normal to me. On the upside, by the time you have finished fixing everything, you will understand it all perfectly.

[sailingharry]

Originally Posted by Captain Bill

Do you plan to stay on the hook in Palm Beach or are you planning to cruise? If you are planning to cruise the Bahamas or Caribbean then you might want to move your wind generator to the port side. With the prevailing wind being out of the east (NE-SE) you will have less shadowing issues, especially in the winter with the wind generator on the port side.

A thought I've often pondered with regard to a wind generator shading solar panels is "is it worth it?" A wind generator output curve is horrible -- at wind speeds below 20 knts, they really go south. Practical Sailor did a test a few years back (here, not behind a paywall https://www.practical-sailor.com/iss...rs_5467-1.html) where Day 3 was winds around 10 knots, and the best units put out less than 10Ah -- or about 1 hour of solar on a 100W panel.


The question becomes, is a wind generator that can on a good day put out 10A Ah or more (winds sustained over 15 knots), worth the risk of shadowing 200W of solar panels (which routinely can put out 50Ah almost every day if they aren't shaded).



If I had both installed, I think I would pay very close attention to the trade-offs. And if I didn't have a wind generator, I'd be very skeptical about the benefit of installing one.

[CaptFigmo]

Replace it.
Controllers are cheap.
I carry a spare.
Make sure you disconnect input from panels before you disconnect output to batteries.

[newhaul]

Originally Posted by sailingharry

A thought I've often pondered with regard to a wind generator shading solar panels is "is it worth it?" A wind generator output curve is horrible -- at wind speeds below 20 knts, they really go south. Practical Sailor did a test a few years back (here, not behind a paywall https://www.practical-sailor.com/iss...rs_5467-1.html) where Day 3 was winds around 10 knots, and the best units put out less than 10Ah -- or about 1 hour of solar on a 100W panel.


The question becomes, is a wind generator that can on a good day put out 10A Ah or more (winds sustained over 15 knots), worth the risk of shadowing 200W of solar panels (which routinely can put out 50Ah almost every day if they aren't shaded).



If I had both installed, I think I would pay very close attention to the trade-offs. And if I didn't have a wind generator, I'd be very skeptical about the benefit of installing one.

a couple of minor points to make here. First a 100 watt solar panel is maxed at 5.7 amps
My airx 400 produces 10 amps at about 12knots wind at 20 knots its putting out its max of 29.5 amps. Doing the math here . Even if it only puts out 10 amps for half the day that is = to 120 ah. In winter I need it due to lower solar output .
As to the noise factor lightly sanding the edges of the blades ( slightly rounding the sharp edges) will significantly reduce the noise without affecting the performance.

[carlwk3c]

Originally Posted by Kalimniosjohn

Just an update. I actually went with a single victron SmartSolar controller and will get a second when I get around to installing more panels.

I installed it last night when there was no sun. So far today it seems to be doing a fabulous job. Hopefully it isn’t already too late for my batteries. Here’s a couple screen shots I took around 230pm today. Haven’t gotten to float charging yet, but the batteries started off pretty much dead.

I love the monitor on my phone too. Definitely glad I went with this unit.

Get the 712 battery monitor. Install the shunt as directed. Measure amps in and out state of charge, etc from its panel or your phone. Has alarms, relay output, etc.
I love my Victron MPPT and battery monitor. Plan to replace our old Xantrex inverter/Charger with Victron

[carlwk3c]

Originally Posted by Kalimniosjohn

Yeah the last two days I’ve been in float charge by 1pm so it’s definitely much better then what I had.

I only got a 100/30 controller because I will be adding a second soon when I get two more 150watt panels. Then I’ll have a 240 watt and a 150 watt panel on each charger.

Make sure you match panels by output voltage. Don’t mix and match (parallel) panels of different voltages.
I have 2 LG 350W in parallel to a Victron SmartSolar 150/85. I would not add different panels in parallel.