solar controller

Bill Gerrie · October 11, 2016, 05:53:14 AM

Does anyone know of a 30 amp solar controller with a digital readout of the charging current from the solar panels. I have tried 2 different ones and they are garbage. My batteries are at 16 volts when the sun is out. Too high.
Thanks for any suggestions.

scanzel · October 11, 2016, 06:14:37 AM

Outback is one that you may look into, you did not say what your are using now.

Brian Diehl · October 11, 2016, 07:31:53 AM

I highly recommend Blue Sky controllers. I use a Blue Sky controller on my 530watts of panels and have had no issues. It is a MPPT style controller and has worked exceptionally well this summer. I generally am able to harvest usable power even when it is raining and cloudy outside.

Bill Gerrie · October 11, 2016, 08:21:35 AM

Thanks guys. I have a Power Jack and it doesn't seem to control the voltage. I will look into the mentioned ones.

Iceni John · October 11, 2016, 09:40:59 AM

Hi Bill,

I have two Morningstar TS-MPPT-60 charge controllers for my PV system. Their displays show current flowing into the batteries, and lots more stuff I don't usually care about. The 45 amp version of my controllers uses the same displays, either one mounted on the front of the controller itself, or a remote display that can go anywhere. Morningstar also makes smaller CCs, but they don't have such comprehensive displays as the TS series.

If you're thinking of getting another CC, I'm very pleased with my Morningstars. They are probably the most efficient CCs made by anyone, they don't use a fan for cooling (fans can be a major potential failure point in a dusty environment such as a bus or RV), they have enough choices of charging parameters to suit almost any type of battery, and for the techno savvy they can be connected to a computer for remote operation and monitoring and uploads and all that fun stuff I don't understand!

John

Bill Gerrie · October 11, 2016, 04:56:35 PM

Thanks John. I will look at them.

Beachfinn · October 12, 2016, 05:10:42 PM

I have midnite solar kid with 400w of panels, seems to do a pretty nice job with my bank. I'm planning on getting another one with 400w more. It would probably do even better if I really got into the settings. But I'm lazy and my bank (1200a) was a very cheap buy and I'm not expecting a very long life out it. That being said the controller has just about every readout and setting you can imagine...

Sami

Bill Gerrie · October 12, 2016, 05:50:10 PM

Thanks Sami

Cary and Don · October 12, 2016, 06:28:56 PM

We have the Morningstar mppt controller also. It has been great. First, you want an mppt controller. Start out with the 60 amp controller, you may decide to add to your panels at some point. These things are expensive so you don't want to buy a second.

Don and Cary

Bill Gerrie · October 13, 2016, 04:46:28 AM

I definitely am looking for a MPPT controller this time. Also looking into series wiring for the panels. Problem there is panels are two different wattages. Two are 80 watts and two are 100 watts. Looking at maybe a series/parallel set up.

Iceni John · October 13, 2016, 07:45:00 AM

Regarding series wiring of your panels, bear in mind that if one panel is partially shaded and producing negligible power because of that, it will also affect total array output. Partial shading can be as innocuous as a leaf covering one cell. This is more of a problem if you have panels with all their cells wired in series; a panel with half its cells in series will be less affected.

Also, MPPT change controllers are most efficient when the PV array voltage is about twice the batteries' charge voltage. When they have to down-convert a large difference in voltage (such as if you have a series-wired array) their efficiency reduces significantly. For example, my Morningstars have an efficiency up to about 98% when handling a 2:1 voltage drop, but their efficiency drops to the low 90s % when stepping down higher voltages. Lower efficiency means more heat production, and we all know what heat does to electronics!

FYI, I have essentially two separate systems running in parallel - each group of four panels is wired in parallel to produce about 34 amps at 30 volts, then their CC converts that to a maximum of 60 amps at 14.7 volts. Because of this low stepdown ratio, their heatsinks get only slightly warm to the touch even during Absorb charge mode. If my panels were in series, the CCs would be running much warmer.

John

Bill Gerrie · October 13, 2016, 11:38:13 AM

John
My concern is that series connection of the two 100 watt panels and series connection of the two 80 watt panels then put the two sets in parallel will they work better then putting them all in parallel. I am convinced the MPPT controller is worth the extra money.

Iceni John · October 13, 2016, 12:12:16 PM

Just try to match voltages, otherwise the MPPT will get confused and not know which maximum power point to track!

John

eagle19952 · October 13, 2016, 12:16:57 PM

Quote from: Iceni John on October 13, 2016, 12:12:16 PM
Just try to match voltages, otherwise the MPPT will get confused and not know which maximum power point to track!

John

so is it possible to match a 100 with an 80 watt and then combine essentially making 2 180 watt panels ?

Iceni John · October 13, 2016, 12:24:26 PM

Quote from: eagle19952 on October 13, 2016, 12:16:57 PM
so is it possible to match a 100 with an 80 watt and then combine essentially making 2 180 watt panels ?

Maybe, if the voltages are close. It's worth perusing the Northern Arizona Wind & Sun forum to glean information about this - I've not researched it that thoroughly simply because I have matching panels.

Plan B could be to sell the odd mismatched panels and buy some all the same. Prices for big grid-tie panels are still low - I paid well less than a dollar a watt. It's much easier to have a few large panels than a plethora of small ones.

John