Mini Solar Generator (The Grizzy Cub 90)




Introduction: Mini Solar Generator (The Grizzy Cub 90)

Here is my step by step Instructable on how I made my mini solar generator. I made this one because it will be more compact than lugging around my larger one which weighs around 27kg (60 pounds). This one will be less than 3kg so of course it won't power a mini refrigerator or start my car like it's big brother but it will charge a few mobile phones/tablets and run a small oscillating fan at the lake in the summer. I have 3 folding solar panels that I use to power my things while camping but i think a 45w will suffice for this little one.

Parts I used:

1x Hot glue gun case
2x Toggle switches
1x 7.2Ah Battery
2x 12v Power outlet
1x 3a Double USB Port
1x 5w LED light
1x 12v Battery Gauge
1x 45w folding solar panel
1x  220-240V 500mAh European Charger.
1x 12V Cigarette Lighter Plug.

* Various lengths of red and black wire.  
* Twist ties
* Duct Tape

YouTube video showing my larger system with panels.

note: just added a 12 volt plug to the mini solar generator and now I can charge it up while driving around.

Step 1: Parkside Hot Glue Case

I'm using a case that I had lying around from a non functioning hot glue gun. The firs step is to remove the hard plastic lining interior.

Step 2: Cutting Like Crazy!

I removed the interior plastic supports for the hot glue gun with my trusty Swiss Army Knife. There are easier ways I'm sure but 'Big Red' is always sharp and ready and it's small enough to get into tight spots. The interior needed to be removed to allow space for the solar generators components.

Step 3: Tidiness Is Paramount!

Unfortunately for me it's winter time so I can't use my unheated garage for my projects. I am reduced to using the dining room table for my workbench.

Step 4: Easy Drilling & Gluing.

I use a cordless drill and hot glue for most of my homemade projects. In this picture I have simply drilled a hole and placed a 5w LED light into the spot.

Step 5: LED Closeup

Here is a closeup picture of my 5w LED light. The hole was drilled and filled.. no pun intended :D

Step 6: Power Switch

I have had this toggle switch lying around for about 3 years and it has been used inside various devices during that time. It's a powered switch but the light burned out ages ago but it still switches the power on and off so a new one wasn't needed. I like to recycle stuff when I can instead of throwing it away.

Step 7: Location Location Location

I have the 12 volt outlets and USB port outlined in paper and taped to the hot glue gun case so as to give me some reference to how things will be positioned when it's finished.

Step 8: USB Ports

In order to install the USB ports I took a 12v double USB cigarette lighter adapter and hot glued it into a small hole I cut with my Swiss Army Knife. The edges of the cut look rough but are not visible once the USB ports are installed. I am using a 3A USB adapter in this case.

Step 9: Inside View

Here is the inside view of the case showing the USB adapter after being glued into position.

note: The adapter is simply placed into a precut hole and held with hot glue.

Step 10: Double USB

Here is a closeup picture of the double USB port. I use simple tools and hot glue when I can. My cuts are a little jagged and I measure everything by eye, but it seems to work for me. This hole was cut out with my Swiss Army Knife and the USB adapter placed inside it... simple.

Step 11: 12v Sockets

I used this 12v socket multiplier that I had on hand from one of my earlier solar generators. I took it apart before I had a chance to take a picture of it for this step so I crudely stuck it back together so you could see what it looked like before disassembly. Two of the sockets shown here are for normal 12v use and the other is for a cigarette lighter. I don't smoke but it's good to have for starting a fire quickly and with what you have already.

Step 12: Disassembly

I disassembled the 12v socket multiplier and used only the two regular sockets. I set the cigarette lighter socket to the side for later use... it may wind up in a future project.

Step 13: Full Frontal

Here is a full frontal view of the USB ports and 12v outlets. The power switch is visible just to the left of the carrying handle.

Step 14: Side Angle

Here you can see the 5w LED light, 12v power outlets and USB ports.

Step 15: Open Up!

The inside of the case shows the USB ports to the left and the two 12v power outlets to the right. Both are hot glued into place and I used part of the casing from the 12v power outlet multiplier to add reinforcement to the inside of this one. I needed to do this as the plastic for this case is very thin and the repetition of inserting and removing 12v plugs would have weakened it too much, but it seems to be very firm now.

Step 16: Wire It Up!

Here is where you need some basic knowledge of a 12v system. I've wired up the LED light, USB ports, toggle switch and 12v Power outlets. I am using a 10a inline fuse that I found lying around but will switch it to a 20a sometime in the future even though I don't expect to be powering much with this. I used shrink tubing until it ran low then I used electrical tape which works equally well.

Step 17: Testing My Connections.

I used a 12v power box with jumper cables in order to test my mini solar generator out as I didn't have the battery ordered at the time I wrote this.  After running some tests I figured out that I forgot to wire up one of my 12v power outlets, but everything else worked as it should.  I wired up the 12v power outlet and had it powering a 400w inverter in just a few minutes.. much to the chagrin of my wife :D

Step 18: Side by Side

Here is a side by side of what the original case looks like alongside my modified one. Don't worry.. I have at least one functioning glue gun left  :D

Step 19: A Little 12v Power!

I ordered this little 7.2Ah 12v battery just for this mini solar generator.  It's a little heavy at around 2.7kg, but it's manageable. 

Step 20: Changing Positions.

Due to the support I added to one side of the case on the interior I had to slide the battery a little off-center but the weight imbalance is not too pronounced.

Step 21: A Little Support Here.

Here I've added some supports to keep the battery from shifting around while in transit.  

1.  Basically an outline of plastic blocks hot glued into position in order to keep the battery stable.

2.  Some packing material I covered in black duct tape to fill the space between the battery and case.   Now it fits snugly.

Step 22: More Charging Options.

Here I've added a couple more charging options from parts I already had lying around.. as usual.

1.  220-240V 500mAh European Charger.

2.  12V Cigarette Lighter Plug (for car charging)

*note: Both new charging options tested and working.

Step 23: Let There Be Light!

Yeah, it's a glorified flashlight when it's not hooked up to my solar panels or charging my phones, tablets ect.  Some of the packing material can be see behind it.

Step 24: Let's Cool Down!

Here you can see the 'almost' finished mini solar generator attached to a 400w modified sine wave inverter.  When used with the inverter my USB outlets increase to 3 and I can power very small things.  This 7.2 Ah battery can't handle a 400 watt draw for too long but I used this same inverter with my larger system for 8 days camping last year powering a mini fridge with freezer.  I'm upgrading to a 1500w pure sine wave inverter for my larger system though.

Step 25: Before the Cut.

Here is a frontal picture showing my 12v ports all covered up.  I tried to show the front of the case before I began cutting to install the battery gauge.

Step 26: Battery Gauge.

I ordered this battery gauge from eBay (Germany).  It came from China in about 9 days but was relatively inexpensive.  I have the exact same gauge on my larger system as well.  It feels good knowing exactly how much power you have available. 

Step 27: Battery Gauge 2.

Well here is the closeup of the battery gauge and the unit is essentially finished.  It will come in handy when it warms up and the sun comes out to charge all of my batteries.

Step 28: Let There Be Light... Well Sunlight :D

Here is my mini solar generator WITH one of my solar panels.  This one is a 45w solar panel.  I also have an additional 45w and a 120w but I will only use them with my larger system... which I also have an Instructable and Youtube video for.  

Note:  I dragged this solar panel up fron the basement just so you can see it together.  If you want to see it with the sun on the panels you'll have to use your imagination because I can do alot but I can't make the winter sun shine on a dark night.  Therefore, this picture in my living room must suffice.  It's not my only solar generator after all... just the smallest.



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    15 Discussions

    Just a curiousity, but is that a VRLA battery? If it is then is it a bit iffy having it in a sealed case, especially with working electrics in there too.

    1 reply

    My mini Solar Generator is working just fine and the case isn't sealed. I open it all the time to access the 230v and 12v plugs for charging. Besides, this was created by Gregory Parker Sr... it works beautifully.

    Thanks for the input guys it's very appreciated. I've found some 12v 17mA batteries online, would the extra mA over the 7.2mA mean faster charge times for things like mobile phones plugged into the usb slot/s? If I used 3 12v batteries, would that give me 51mA(17x3)? And if that is the case would it be possible to power a single 240v 3 pronged(UK) socket via an invertor for any reasonable length of time? Would you recommend a volt meter when it comes to trickle charging the batteries just so that I don't under or over charge them? Is it safe to charge the main 12v batteries while they are linked together or would I need to charge them individually? Sorry to be a pain in the arse with the questions, but I want to be sure and careful when it comes to battery side of things. :-)

    I only added the light because I had it lying around in my toolbox from a couple years ago. In fact, the only things I bought for this project were the battery and battery gauge.

    As the title is Mini Solar Generator, I have to ask: where is the solar panel for generating the electricity that charges the battery? Other than that, this is a nice portable backup charging/power station.

    1 reply

    I have added the picture with the solar panels. As stated above I have 215 watts of solar panels.

    I added a picture of the solar panels.. I have a total of 215 watts of them but you get the idea without having to see all of them plugged into my Solar Generator. Thanks for the compliment though. I'll make an upgraded Instructable for my 1500w Solar Generator... that's pushing 200 amps of battery power :D

    This is a fantastic idea and a project I'd like to try myself. It's a 12v battery used and usb is 5v, does the 3a double USB fitting drop the voltage down to 5v? How could I make a more beefed up version, would it be as simple as using 2 of those batteries in the unit? Also, would you be kind enough to draw a rough and ready wiring diagram please. This is perfect for my camping trips and would like to try and make this project myself. A beefier version would be even better. Thanks for posting this project, brilliant and useful in a practical casing.

    2 replies

    Yes, the voltage is dropped down to 5v for USB. I chose a 3a USB port because it charges faster than a normal 1.5 or 2 amp port. I made a 'beefed' up version last year. I have since upgraded that system to a 1500 watt pure sine wave inverter and 2x 100Ah batteries. You can check out my other Instructable but it's not been updated since the new upgrades. I'm working 6 days a week so I don't knwo when I'll get around to any diagram, but this is a simple system. It's just cut, glue, wire it up.

    the usb "ports" are an automotive 12V to dual 5V usb adapter (cheap at gas stations dollar stores or electronics store . probably $6 ) It normally plugs right into an aux power port(cigarette lighter socket) and outputs 1-2 amp over it's usb ports

    One more question if I may. What type of mains charger would I use to charge the 12v battery, could you use a car battery charger at all?

    2 replies

    As for a wall charger, I have successfully used a 500ma charger with crocodile clamps to trickle charge batteries of this size and larger. Take into account that the larger the battery the longer the charge time. Try not to overload your battery with too many amps at once though.

    a "trickle charges" would work, but a full automotive charger may be too powerful. some charges will have a low power mode that would work but a cheap auto battery charger will try and pump in too much amperage, and will probably destroy your battery.
    you could even use a 13 volt laptop power supply,but care would be needed as there would be no change control .