PDA

View Full Version : Recommended solar charge controllers



KC7YRA
07-21-2012, 01:35 AM
Howdy all,

I am in need of a solar charge controller. My existing one has failed, but it wasn't fitting the bill anyway.

I have a foldable 20 watt panel for backpacking. I want/need a controller that is robust but physically small. Nothing high draw. Just charging HTs and such.

What do folks recommend.

Brad

KD0CAC
07-21-2012, 01:23 PM
As the charge controllers get smaller [ current wise ] they have fewer options .
It sounds like just some general charging .
A good charger should have the ability to be programed for the type of battery being charged so you get good battery life , each chemistry has its own charging profile .
I do larger systems , have not put together something like what you mention , so I have hot looked for that application , I suspect like mentioned above limited options .
I would like one of the flexible panel sets , but they over charge $$$ so much , I refuse to pay the ass-in-nine prices , with the large system I see $2 per watt and do not accept anything over about $4 per watt .
Most of the flex panels seem to be well over $10 per watt if not over $15 per watt .
Here's a few suppliers ,
http://www.partsonsale.com/products.html#anchor855710
http://www.wind-sun.com/ForumVB/index.php
http://www.backwoodssolar.com/

KF7ORO
07-21-2012, 01:47 PM
The ARRL Handbook has a couple designs in it that you can build yourself if you don't find something you like.

AD7N
07-22-2012, 05:12 AM
Howdy all,

I am in need of a solar charge controller. My existing one has failed, but it wasn't fitting the bill anyway.

I have a foldable 20 watt panel for backpacking. I want/need a controller that is robust but physically small. Nothing high draw. Just charging HTs and such.

What do folks recommend.

Brad

Who's the manufacturer of your folding solar panel? My first recommendation would be to see what kind of charger controller they offer as an accessory.

AE7UT
07-22-2012, 06:33 AM
You've probably already seen this one on the Buddipole site.
I thought it looked just right for my applications.
http://www.buddipole.com/sobaco.html

Stan AE7UT

KC7YRA
07-22-2012, 01:36 PM
Thanks for the replies. I have been digging through them all morning.

My solar panel manufacturer recommends Morning Star (or whatever it is) controllers and quite honestly, I think they are garbage. The reviews on Amazon completely echo my problems with them.

I will look at Buddipole as well. I never knew they had them.

Brad

AD7N
07-22-2012, 03:17 PM
Thanks for the replies. I have been digging through them all morning.

My solar panel manufacturer recommends Morning Star (or whatever it is) controllers and quite honestly, I think they are garbage. The reviews on Amazon completely echo my problems with them.

I will look at Buddipole as well. I never knew they had them.

Brad

Brad - what is the make/model # of your 20W solar panel? The reason I ask is because it would help us pinpoint the ranges the panel puts out/can handle. That would help me at least pick a charge controller that is best suited for your panel. :D

KB0MNM
07-22-2012, 06:24 PM
FYI My new employer does the industrial panels. Due to the nature of this board, and my inexperience with the product: I can only state that there are different grades of products for different markets, even from the same maker. Send me a private e-mail if you want the specifics that I can glean while at work next week. Better yet, you may wish to try the new communal e-mail box: techsupport@twrlighting.com. (This may be referred to sales or meet with an e-mail set-up delay of about a week). 73

Howdy all,

I am in need of a solar charge controller. My existing one has failed, but it wasn't fitting the bill anyway.

I have a foldable 20 watt panel for backpacking. I want/need a controller that is robust but physically small. Nothing high draw. Just charging HTs and such.

What do folks recommend.

Brad

K0RGR
07-22-2012, 06:39 PM
Be sure that you determine the RFI potential of the controller. I understand that most of these are PWM devices that generate beaucoup RF noise. The one from Buddipole is interesting - you should be able to find out from them if their unit is RF quiet. We had a presentation some time ago at a radio club meeting from a ham who has gone essentially all solar, and he had some specific chargers that he recommended. Unfortunately, I have lost my notes from that meeting. The fellow who gave the presentation was Craig, AC0WQ - his snail mail address is listed here on the Zed - might be worth dropping him a letter. Apparently, there are some charge controllers that do their PWM switching at such a low frequency that they don't generate any RFI.

NC5P
07-22-2012, 08:33 PM
Be sure that you determine the RFI potential of the controller. I understand that most of these are PWM devices that generate beaucoup RF noise. The one from Buddipole is interesting - you should be able to find out from them if their unit is RF quiet. We had a presentation some time ago at a radio club meeting from a ham who has gone essentially all solar, and he had some specific chargers that he recommended. Unfortunately, I have lost my notes from that meeting. The fellow who gave the presentation was Craig, AC0WQ - his snail mail address is listed here on the Zed - might be worth dropping him a letter. Apparently, there are some charge controllers that do their PWM switching at such a low frequency that they don't generate any RFI.

The topology, frequency (or range of frequencies), and component values (inductor, input/output capacitors) will have a huge influence over this. Ringing at higher frequencies can also occur in the inductor circuit during discontinuous operation (light load) and if that happens within an amateur band you will hear it. I've seen ringing up to six meters in some switchers. That can be fixed with snubber (RC or RC + diode) across the inductor. These controllers may use a buck/boost, flyback, boost, or buck converter design to charge the battery. It depends on the output voltage of the panel, battery voltage, and amount of power what topology is used. Buck-boost is most often used for 12 volt panels and 12 volt batteries. Unfortunately, that makes conducted noise analysis difficult because in buck most of the noise goes out to the input due to non-continuous conduction on that port and in boost most of the noise goes to the output for the same reason. A buck/boost will change from one to the other depending on sunlight, state of battery charge, and load. I would be more concerned with output noise because that is going into your radio. There is also radiated noise and that can be reduced with proper layout, metal enclosure, and using a shielded inductor (pot cores are great for that). Carrier harmonics can be reduced by spread spectrum modulation of the PWM controller. It still generates noise but it's spread around more. I believe however this isn't always the best practice since one can sometimes cope with specific frequencies better than raising the noise floor over a larger portion of the band.

One can often clean up a noisy switcher by isolating the ports through appropriate filters and placing it in a shielded box. The feedthru types are very good and available at several surplus dealers.

ad: giga-ldg