Closer Look at the CMP 12/24 Solar Charge Controller

So I have been using my portable solar power system since I first posted about it and I am learning a lot more about solar along with more about charge controllers and batteries. The CMP 12/24 is a Chinese imported solar charge controller that you can get cheaply off of eBay. They claim it is a PWM controller but I have read that others say it is just an on-off controller and not much more. I know for a fact it does limit voltage out from your solar panels. It does not let 20 volts go directly into your battery but I am still learning how to tell what else it does electronically. Here is a closer look at the circuit board and components of the PWM controller. I took a lot of close up pictures of both sides of the circuit board.

CMP 12 Charge Controller

Bottom View CMP 12/24

CMP 12/24 Circuit Board View

CMP 12/24 Cicuit Board View-Top

CMP 12/24 Circuit Board View - Bottom

Cleaned Up Version of my Portable 60 Watt Solar Set Up

My 60 watt solar energy system has been working great. I get great power from the Sunsolar 30 watt panels. My cheap PWM solar charge controller does a good job at regulating the power that comes out of my panels. Here are some specifications on my outputs and measurements:

• 30 Watt Sunsolar panel puts out 20.5 volts in full sun.
• The CMP 12/24 solar charge controller at full power regulates input voltage to battery to around 13.6 volts.
• The Cobra 400/800 watt inverter #CPI 475 measures 110 volts with a 100 watt load. This may go up when battery is on full charge.

I recently made some upgrades to my solar set up to clean up the wiring and add a simple automotive voltmeter. I will stress again that it is very important to put a fast blowing fuse on the power line going to the 12VDC side of your inverter to help you form accidentally cooking it. Here are some high points of my upgrade:

• Added $8.00 large battery box from Walmart to hold all the vitals inside.
• Added $7.00 automotive voltmeter from Harbor Freight
• Panels are now wired with a quick disconnect plug made from a computer power supply. I found a 16 gauge power supply wire and traced a positive and negative to the inputs on the charge controller.
• This system is now totally portable and safe.

Here are some good pictures of how it looks now.

60 Watt Self Contained Portable Solar

Solar Battery Box Enclosure

Side View of Battery Box

Back View of Solar Battery Box

Top View with Cover Off

Top-Back View Isometric

Top-Front View Isometric

My 60 Watt $144 Dollar Solar Power System

As I described in my first post, I finally got started on building a little portable solar power system. So far I have spent $144 on a system that is made up of the follwing components:

• (2) SunSolar 30 watt solar Panels - $116 total
• (1) CMP 12/24 Solar Charge Controller - $12
• (1) Cobra 400/800 Watt Inverter - $16
• Old deep cycle battery - free
• Odds and ends - free

I mounted both of my panels together using leftover 1/2" aluminum channel like the kind you get from Home Depot. I then build a platform for my battery to sit on that would hold the rest of the electrical items. The best thing I did for this little cheap system was to put a 15 amp fuse between my inverter and battery. This saved me from burning up my inverter when I plugged something in that was too big for it. Here are some pictures to enjoy.

60 watt Portable Solar Power with Inverter

SunSolar 30 Watt Panels

Solar Panel Parallel Connection

Solar Panel Connections Up Close

Battery, Inverter, Charge Controller Combo

Free Electricity from the Sun

That Little Fuse Saved my Inverter

First Solar Hardware Purchase

I was on eBay last month looking up solar charge controllers and I finally pulled the trigger on purchasing my first piece of solar hardware. I sniped a little cheap charge controller from a guy in California. It is a CMP 12/24 PWM 10 amp charge controller. I next needed panels so I purchased two 30 watt Sunsolar panels form eBay as well and they look and work great.