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A Little Solar Charge Controller that may be able to do more! (Read 56689 times)
electron
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #19 - Feb 19th, 2016 at 9:37am
 
debianxfce wrote on Aug 24th, 2015 at 3:22am:
I have CMP 12 for 80Ah 12V boat battery and 30W solar panel. It worked ok for several weeks until i made a short circuit to the alternator + connector while adjusting the alternator belt in Yanmar 2GM20. My mistake did blow a usb charger (it gives 12v to usb) and over voltage did blow Mini DV spy camera that was powered via usb.

After using Webasto 2000 heater (2-3A load) one night the battery charged by solar panel with 20 sunny hours and now battery is cooking and battery voltage is 14.3V when the panel is in the sun and 13.7V when the panel is not.

Is the CMP 12 protected for short circuits at the battery side?
How do i test the charging limiter of CMP12?
The CMP is working when you get to something like 14.5 to 14.9V (depends on unit) and then it starts backing off, meaning the little green LED will start turning off. When it does this it opens the (-) side from the solar panels so if you measure across that you would start reading voltage (that is pulsing to start out so your meter won't like that).

Also, just recently I put more panels on one of these that I "beefed up" as you see in the pictures below with thicker traces and a extra heat sink off to the side.

It went up to 26A at one point when I had the "cloud effect", so that was only maybe 15 seconds, and the temp of the mosfet was up to 177F. I regularly run it at 150F and about 20A is typical. It seems to handle this OK. This is on a 24V battery system.

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debianxfce
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #18 - Aug 24th, 2015 at 3:22am
 
I have CMP 12 for 80Ah 12V boat battery and 30W solar panel. It worked ok for several weeks until i made a short circuit to the alternator + connector while adjusting the alternator belt in Yanmar 2GM20. My mistake did blow a usb charger (it gives 12v to usb) and over voltage did blow Mini DV spy camera that was powered via usb.

After using Webasto 2000 heater (2-3A load) one night the battery charged by solar panel with 20 sunny hours and now battery is cooking and battery voltage is 14.3V when the panel is in the sun and 13.7V when the panel is not.

Is the CMP 12 protected for short circuits at the battery side?
How do i test the charging limiter of CMP12?
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electron
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #17 - May 8th, 2015 at 9:33am
 
mike s. wrote on May 8th, 2015 at 7:06am:
I'm on my second "cheapo" solar controller for my driveway gate. The first one probably crapped out when I accidentally wired in the solar panel before wiring in the battery, which was a no-no in the directions. ....
I haven't seen a spec for the max voltage on this controller.

But when your batteries are fully charged, the "charge" LED is off and so are the charging mosfets.

Which means your solar panels are not loaded so they are around their open voltage, which could be close to 40V for 24V panels.

When diagnosing a problem like that you don't want to start with the most costly method first, you would want to check things with your DVM first, check connections, check for shading at the panel (weeds / plants), clean the battery contacts, check the specific gravity of the battery (charged), maybe put it under a known load and watch it (you should already have an idea of what a good battery does under that load), check your gate motor to see if maybe it's pulling more amps than normal (crap in the gears, old grease, binding up, wheels rusted) or maybe running when you are not watching.

The LEDs are a general indication of charge, use your meter.

Batteries will run down a little at night, they have their own internal resistance, but it's not that much.

The Walmart Auto Center has a nice battery checking meter thing, some auto parts stores do too, not saying buy one even though you can buy a simple load tester, this is a nice one they use at the store. You can always take your battery in and ask nicely to have them check it, it will put the battery under load.

The bottom line is, use your meter. If the LEDs did go bad you should be able to tell what is going on.

When Lead Acid batteries are old and sulfated, generally they charge up fast but then run down fast. That is why I said do a load test.

That generally happens at about 5 years on the low cost deep cycle batteries (like walmart) and some people have reported 10 years on the expensive made for off grid type deep cycle batteries.
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mike s.
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #16 - May 8th, 2015 at 7:06am
 
I realize that this thread is pretty old, but maybe someone can help, anyway. I'm on my second "cheapo" solar controller for my driveway gate. The first one probably crapped out when I accidentally wired in the solar panel before wiring in the battery, which was a no-no in the directions. It wasn't a CMP-12, but something similar. Now I've been using a CMP-12 for about 7 months. It seemed to work fine, but recently the batteries (2 x 12V for a 24-volt system) have lost power every night and then are ok after an hour or so of sun in the morning. I figured that was a battery problem and changed them out with 2 new deep-cycle 12V batteries. The old batteries turned out to be fine, showing about 13V each, but two of the terminals (one on each battery) were corroded. Maybe that was my problem, though since the batteries were fully charged I don't know how/why I was getting no power for the gate in the morning. Anyway, the CMP-12: It has 3 red LEDs showing battery charge. After I replaced the batteries, the CMP-12 showed 2/3 full and then full battery charge (so the LEDs were working correctly). A few hours later in the day the LEDs were dead. Based on you guys' seemingly deep knowledge of this little controller, I think maybe one of you could diagnose what happened. I note that Paul wrote that sources over 28V might cause problems, and my solar panel is putting out around 34V. I know I can buy another controller for around $10 but don't want to continue having problems. Because the "charge" LED is green, is it possible that all is ok with my controller (regarding controlling battery charge) and the LED circuit just burned out? Thanks for any help!
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« Last Edit: May 8th, 2015 at 7:43am by mike s. »  
denny
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #15 - Jan 14th, 2014 at 12:11am
 
I am looking on an MPPT, which has a good efficiency, and when I search the Google for a while. coming out some Mppt, do you know how to choose a solar charge  controller. any instructions?
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #14 - Dec 19th, 2013 at 10:30am
 
Thnaks
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electron
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #13 - Jul 15th, 2013 at 4:20am
 
I took some pictures of my heat sink and beefed up traces mod.

I've been running this for more than a year now and have seen it being pushed to 20A. It works at 15A regularly every day. I monitored the heat sink temp and even when the room is over 90F it only goes up to about 115F at around 15A with this small extra heat sink on it.

The heat sink is a old CPU heat sink that is probably from the old 386 / 486 days. It's small enough to not put a big weight on the original heat sink which is held in place by the mosfets only.

I don't know if the beefed up traces are needed since they are pretty wide but it only took a few minutes and seemed like the thing to do. Notice I only beef up the important parts where the big current flows.

A lightning storm came overhead and took out the CMOS chip U2 "HEF40106 Hex Inverting Schmitt Trigger" so I am now using my spare CMP 12/24 (with heat sink mod, same thing) but I will simply replace the chip and I am sure it will work and then it will be my spare. You should always have a spare for equipment this important and at this price, why not?

CMOS chips are known for being sensitive to static discharges and surges can cause them to latch up.

How do I know it's the CMOS chip? Because it's melted in the center where the internal chip IC die is located. If you look close you can see it in the pic. This is normal for a latched up CMOS chip gone haywire.

The voltage the chip runs on varies but never goes above 15V and I checked that so it wasn't a over voltage problem and all it needs is a new chip. Mosfets all check out OK!

This is why I like simple stuff like this, it's easy to fix yourself.

Yes, my panels are grounded and also sit on the ground, the wires are buried, but that doesn't always save you. Lightning is crazy and you never know what it might do. It produces a EMP, a RF pulse(s) of very high magnetics, which can inductively couple into your wire UNDERGROUND or simply travel as RF down a wire. Lightning is very high power. I looked and it wasn't a direct hit as far as I can tell, no burn marks I could see, but small "streamers" are known to scatter around a lightning hit.


UPDATE: Replaced U2 and everything functions OK again.

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cmp12-24-heat-sink2.jpg (178 KB | 594 )
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Aric Dyson
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #12 - May 2nd, 2013 at 10:00pm
 
With regards with this solar charger controller? Where can I buy this kind of controller? I can't wait to get and buy this stuff hope you can help me. Keep posting
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« Last Edit: May 2nd, 2013 at 10:01pm by Aric Dyson »  
andrew_paul111
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #11 - Nov 16th, 2012 at 1:55am
 
Wow! It is great news... Cheesy
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electron
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #10 - Oct 13th, 2012 at 9:20pm
 
rgjohn wrote on Oct 13th, 2012 at 8:11pm:
Do you think that the load (bulb) outputs of 2 or more of these controllers could be connected to the one inverter load?
Batteries are such pain in the ass!

I understand what you mean. You really have to buy them all at once so they have the same lifetime.

This controller switches the ( - ) leads so that makes things a little strange. I think if one output was on and the other was off it might send -V into the "load" mosfet depending on the battery voltages so I don't know if that would be a good idea.

You might be able to build a circuit to do what you want with a bunch of mosfets, start out with two and go from there.

Problem is if one mosfet goes out the others would have to take on more current and if they are not rated to the full output needed for your inverter, you will pop mosfets.

You are right about the diode 0.7V (typical) voltage drop, it would make the inverter shut off sooner, but it would work.

Easiest way is to always buy all the batteries at one time and have as few as possible.

There are some new types of batteries coming out, we have to hope the price will start dropping on those soon.
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #9 - Oct 13th, 2012 at 8:11pm
 
electron ... thanks for looking into these little controllers. My question (if you have time to answer):
Do you think that the load (bulb) outputs of 2 or more of these controllers could be connected to the one inverter load? I run a very low cost solar system and the hardest and costliest thing is the batteries. I don't like running batteries in parallel, particularly second hand ones so would it work if I had separate pv panel(s) and one of these controllers for each 12V battery bank? Then take the outputs of each controller to the one inverter. Would they interfere with each other?
I suppose an alternative to connecting the outputs could be isolating diodes between the positives of the banks and the inverter input. The diode voltage drop would be a problem and maybe it would interfere with the battery voltage sensing by the controllers.
What do you think?
At the moment I have 3 banks of 2x6V 200Ah batteries. These 3 banks in parallel worry me as if one cell goes it will take out the lot if it happens when I'm not there for a while. So I'd like to have 3 sets of panels running 3 controllers into three seperate 12V (2x6V) banks.
cheers
John
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jack
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #8 - Jul 24th, 2012 at 7:21pm
 
it looks so good
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electron
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #7 - Jul 15th, 2012 at 11:59pm
 
soundbyte wrote on Jul 15th, 2012 at 9:31pm:
Have recently bought one of these controllers and it worked well for about a week.

It now does not light the solar panel led and so will not charge the battery.

Now looking for a schematic to check what has failed.

If any one could help with a schematic that would be much appreciated.

Thanks

There's two main mosfets for charging, look at the bottom of the circuit board and you can figure out which two are in the charging part on the (-) leads. The other one is the same type of mosfet but it's used for the "light bulb / load" output.

There's your spare mosfet!

Check the mosfets with a ohm meter, they mostly fail SHORTED, so it may be easy to find the problem.

Do some basic stuff, check the transistors and diodes on the board, they would be the easiest to replace. The surface mounts chips are a pain to replace and hardest to figure out if they are bad unless they are totally dead.

Sometimes with a little patience you can bid these at $5 with free shipping so there comes a point where it's not worth messing with and just call it spare parts.

If you do find out what went bad you want to think about why it went bad so it doesn't do it again, did you have a surge? Is there something in the circuit that could send higher voltage pulses down the wires?

It may help to add a capacitor near any device that you think may be sending spikes down the line.
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soundbyte
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #6 - Jul 15th, 2012 at 9:31pm
 
Have recently bought one of these controllers and it worked well for about a week.

It now does not light the solar panel led and so will not charge the battery.

Now looking for a schematic to check what has failed.

If any one could help with a schematic that would be much appreciated.

Thanks
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electron
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #5 - May 8th, 2012 at 9:52am
 
I ran a test with this charge controller and a 300W Grid Tie Inverter connected to the same solar panel and the results are good.

I hooked the GTI up as usual, direct to the solar panel. The grid tie is the 14V to 28V input type.

I also hooked the charge controller to the same two wires from the solar panel, it was now in parallel with the GTI.

The 12V battery was hooked up to the two terminals for the battery. ALWAYS hook up the battery first!

When you do this what happens is the battery will go to about 14.7V (or where you adjusted it with the little POT inside the controller) and any leftover energy will now go to the grid!

Some energy is always required to keep a battery charged so this is cheap way to keep a battery charged for emergencies. The rest can lower your power bill.

If you run down that battery, GENERALLY the solar power goes to charge it up first, because the GTI won't kick in till it sees about 14V. BUT.....

SOME IMPORTANT POINTS:

The GTI tends to pull on the battery too much in the mornings so you DO NOT GET A GOOD CHARGE FIRST THING IN THE MORNING which is not good for sulfation! Once the GTI pops on it will actually pull it down to a lower voltage than 14.7V

At 14V the GTI does not perform well, would be better to run it at 24V.

The battery (-) is switched on and off by the solar controller, so the battery can NOT be connected to your whole system if the solar panel is also part of that system.

So if you do this that battery and any loads you want to drive with it should be separate, or your panel has to be separate. I hope that makes sense.

Second thing, depending on how you set up your earth grounds, you want to check and make sure the GTI's ground and (-) are separate and floating, they generally are but just check that and make sure if you going to have the solar panels separate from the ground on the battery.

Third thing, you should use a 50W or better solar panel so the voltage can come up enough even with the GTI running that there is some voltage left to put a little into the battery to keep it topped up.

This is not the BEST way to do this but it's better than nothing. If it's confusing, just draw it all out.
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electron
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #4 - May 8th, 2012 at 9:36am
 
Paul wrote on Jan 4th, 2012 at 7:03pm:
Bought one of these circuits to regulate the battery charge for a old diesel AC generator with a 24volt control panel, the rectified "DC" supply voltage was to high and blow the two controlling IC, so I reversed engineer it by drawning a schematic of this PCB to find out how it work, I replaced the IC U2 (Cmos schmitt trigger NOT gate x 6) and U3 (Oprational Amplifier x 4) to get it working again. I found that the U2 component was a high-voltage gate that only Texas Instruments make, its rated up to 20volt and the U3 rated to 32volt max, the way they get round this is to use 15volt breakdown diodes "zener diodes" to adjust Q2 base a NPN transistor which supply the IC with there power.

The pot W2 adjust the supply isolation voltage turning the charging N-Channel mosfet Q6 off by turning on NPN transistor Q1 on via an optical coupled isolator transistor U1..

This forum I found when I when looking for a schematic without success, so desided to share my finding for anybody else that may be having problems, in short make sure your supply doesn't go above 28 volts otherwise may get some problems.. if it does you could try adjusting the the supply mosfet to isolate at lower potential from 28volts its mean't to isolate at, the charge LED will pulse then go out when it is fully isolated..
It would be great if you could post / attach your schematic, even a scribbled down one would be good to have.

U2 is a HEF40106 Hex Inverting Schmitt Trigger
U3 is a LM324 Op Amp

The datasheet I got on the Hex inverter was from Phillips.

One of the things I noticed is that the "load" output will flip on and off very rapidly when it gets near the voltage it should turn off. They could have done a better job on that, but most people won't use it anyway.


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Paul
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #3 - Jan 4th, 2012 at 7:03pm
 
Bought one of these circuits to regulate the battery charge for a old diesel AC generator with a 24volt control panel, the rectified "DC" supply voltage was to high and blow the two controlling IC, so I reversed engineer it by drawning a schematic of this PCB to find out how it work, I replaced the IC U2 (Cmos schmitt trigger NOT gate x 6) and U3 (Oprational Amplifier x 4) to get it working again. I found that the U2 component was a high-voltage gate that only Texas Instruments make, its rated up to 20volt and the U3 rated to 32volt max, the way they get round this is to use 15volt breakdown diodes "zener diodes" to adjust Q2 base a NPN transistor which supply the IC with there power.

The pot W2 adjust the supply isolation voltage turning the charging N-Channel mosfet Q6 off by turning on NPN transistor Q1 on via an optical coupled isolator transistor U1..

This forum I found when I when looking for a schematic without success, so desided to share my finding for anybody else that may be having problems, in short make sure your supply doesn't go above 28 volts otherwise may get some problems.. if it does you could try adjusting the the supply mosfet to isolate at lower potential from 28volts its mean't to isolate at, the charge LED will pulse then go out when it is fully isolated..
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« Last Edit: Jan 4th, 2012 at 7:09pm by Paul »  
SinurnowRonCZ
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A Little Solar Charge Controller that may be able to do more
Reply #2 - Dec 4th, 2011 at 6:25am
 
Isnt Nevada Solar One a 64 MW facility?

And isnt the proposed Ivanpah facility 392 MW?

I guess these are not solar arrays, but solar-thermal. Still its the same in principle, no?
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Katty
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Re: A Little Solar Charge Controller that may be able to do more!
Reply #1 - Nov 5th, 2011 at 3:14am
 
wow its really nice. thanks for the post.
tell me how far is it feasible?
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electron
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A Little Solar Charge Controller that may be able to do more!
Aug 11th, 2011 at 6:02pm
 
This is one of those 12V / 24V 10A Solar Charge Controllers you see on Ebay for around $15. Model "CMP12" or "CMP12/24".

Taking it apart you find that it's a really simple circuit, just a couple of ICs and some mosfets. This is NOT a PWM charge controller, just simple on/off.

The surprise is that there are three RU6099R mosfets. They are rated at 90A !

The TO-220 package limits them to 75A though, which is still pretty high. 60V max. .006 ohms typical on resistance.

And there is room for 3 more on the board!

One of the mosfets is for switching on and off the load, "light bulb". If you were not using the load, you could use that mosfet as a replacement spare.

I am thinking that with a little beefing up of the circuit traces on the bottom side by adding some bus wire and more solder, and maybe adding more metal to the heat sink, you could make this into a nice 20A to 40A controller!

You couldn't build something like this for $15.

It's possible that not all of these have a overrated mosfet in them, but this one did so if you get one you will need to check the mosfet part numbers before you make any further mods.

But the circuit board does have places for more mosfets connected in parallel, and better mosfets are available online.

The two regulating mosfets are connected in series so that one acts like a diode but is turned on during operation so that you don't have a diode voltage drop during the day! Very nice. Pics of the insides, with the solder side of the board follow.

Other parts of interest:
Varistor -Voltage Dependent Resistor MYG 14D 471K
A pot for adjusting something?

The specs (from ads):
1. over-load protection
2. short circuit protection
3. protection from the lightning strike.
4. under-voltage protection
5. over-charging protection 
6. Dimensions: 10 x 9.5 x 3.7cm ( 4 x 3.7 x 1.5 " )
7. Temperature Compensation: -20�C ~ +60�C
8. This product has been certified by CE
Rated voltage: 12V or 24V Voltage of stop power supply *10.8V or 21.6V
Rated charging current: 10A Voltage of resume power supply *11.8V or 23.6V
Rated load current: 10A Voltage of *14V or 28V
Full Charge Cut : 13.7V/27.4V
Low Voltage Cut : 10.5V/21V
Working temperature: -20 ~ +60�C Temperature coefficient of voltage stop charge -3mV/�C/cell

Thanks to "brownbrve" for the pics!

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