Assembling a BootstrapSolar Chi-qoo Solar Battery Charger Kit




About: Ex-software engineer, ex-mountain man, ex-disaster relief volunteer. Currently bootstrappin' a solar kit biz.

The BootstrapSolarChi-qoo is an Open Source KickStarter-funded battery charger kit for recharging or powering small electronic devices like smart phones, iPads, Kindle tablets, Arduino boards, EL wire, and others. It comes as an easy-to-assemble DIY kit that only requires a screw driver and some glue to put together, and does not require any soldering. The kits are partially manufactured and packaged at TechShop in California.

What you'll need:

A Chi-qoo Kit -- The kits are available for purchase from the BootstrapSolar website, but since it's Open Source, you could theoretically make your own from scratch too!
#1 Philips Screw Driver -- That's the "+" type, and a pretty small one.
Glue -- Any glue that works with wood. Standard wood glue will work, though "5 minute" epoxy probably offers the best balance between bonding strength, time to undo mistakes, and curing time.
Time -- Most folks have reported finishing the kit in an hour or less (and as little as 10-15 minutes for those who are handy).

Step 1: Check Your Components

Make sure you have all the parts. You should have:

Enclosure parts
6x wall sections (thin bamboo sections)
1x USB port bezel (says "USB 2" and "i-devices")
1x DC port bezel (says "A" and "B")
1x bamboo bottom plate
1x plastic top plate

Electronic components
1x 6000mAh Lithium Polymer battery
1x USB charger circuit
1x Solar charger circuit
1x Double-ended cable

Small parts
4x roll pins
16x 3/8" #2 screws
1x jumper

Step 2: Assemble the Wall Sections

We'll start with the enclosure wall sections. The wall sections are comprised of the thin bamboo pieces. They will be stacked on top of each other 3-high, to make the tall, thin walls of the battery pack.

1. First note that the wall sections are not left-right symmetrical (as laid out in the first photo).
2. Pick one piece (any piece) and insert roll pins into the larger holes. If the fit is tight, gently tap the pins. Be careful not to stab yourself with the pins though.
3. Once both pins have been inserted fully, apply a small amount of glue. Avoid gluing around the roll pins.
4. Stack the next wall section on top of the first one, again, making sure the roll pins go through the larger holes
5. Repeat for the 3rd piece.
6. Repeat steps 1 through 5 using the other 3 pieces so that you have two wall sections.
7. Wait for the glue to cure before proceeding.
8. Use the 220 grit sand paper (included in the kit) to remove some of the excess carbon residue.
9. In some of the kits, the pins may be longer than the walls are tall. If this is the case, simply use one of the screws to poke them out.

Step 3: Screw on Top & Bottom Plates

Next we'll screw on the top and bottom plates. Make sure your wall sections are oriented exactly as shown in the photo. The bottom plate has different hole patterns on the left half vs the right half, and the wall sections have different width protrusions on the left vs right. These need to match up as shown.

Step 4: USB Port Bezel

Next we'll install the USB port bezel. The USB port bezel is the rectangular piece with the words "USB 2" and "i-devices" etched on it.

1. Stand up the enclosure exactly as shown in the photo. The side with 3 holes in the bottom plate should be up (or the engravings on the bottom plate should read bottom up).
2. Without gluing try fitting in the bezel.
3. If it doesn't fit, use the sand paper to sand down the edges until it does fit.
4. Apply a drop of glue to the middle of the wall sections. DO NOT put glue on the corners, or you might inadvertently glue on the top/bottom plates!
5. Place in the bezel. Make sure the text shows so that the plastic top cover is "up" and the bamboo bottom plate is "bottom".

Step 5: DC Port Bezel

Next we'll install the DC port bezel on the other end of the enclosure. The steps are similar to the USB port bezel:

Important: If your bezel says "L" and "R", you have a Beta kit. See the instructions here.

1. Make sure the enclosure is oriented as shown in the picture, with the 4 holes in the bottom plate up.
2. Without glue, try fitting the bezel. 
3. If it doesn't fit, sand down the edges until it does fit
4. Apply a drop of glue to the middle of the wall sections. Again, don't put glue on the corners to avoid gluing on the top and bottom plates!
5. Place the bezel with "A" and "B" facing out, and closer to the bamboo bottom plate.

Step 6:

Wait for the glue to cure (harden). Then unscrew the top cover, flip over the enclosure, and screw in the 7 screws part way. Do not screw them in all the way! Get them started, so that they just stick out the other side about 1/8" (3mm).

Step 7: USB Charger Circuit

Next we'll install the USB charger circuit.

1. Place the USB charger circuit so that the USB ports stick out through the USB port bezel, and the holes in the circuit board align with the screws from the previous step.
2. Grasp the enclosure and USB charger circuit as shown in the photo (I'm a lefty, so reverse as necessary).
3. Flip over the enclosure while keeping the USB charger circuit in place.
4. Tighten the 3 screws (make sure the screws are engaging the holes in the circuit board)

Step 8: Solar Charger Circuit

Next we'll install the solar charger circuit. The process is similar to the last step.

1. Place the solar charger circuit so that the black barrel jacks stick out the DC port bezel, and the 4 holes on the circuit board align with the screws. (Important note below)
2. Grasp the enclosure and circuit board as shown in the picture
3. Tighten the 4 screws (make sure the screws are engaging the holes in the circuit board).

Update: Some kits have shipped with bezels that were not cut to the correct dimensions. As a result, the barrel jacks may not go through the port openings very easily. One solution is to file away a bit of material off the top of the barrel jack, or to use the sand paper or a knife to make the port opening a bit taller. In either case, only about 0.5mm (1/32") needs to be removed.

Step 9: Connect Solar Charger Circuit to USB Charger Circuit

Next we'll connect the two circuits using the included double-ended cable.

On the solar charger circuit, make sure the cable plugs into the socket labelled "LOAD" (the socket closer to the wall sections).

Note: The cable connector has a protruding ridge and the socket has a matching slot. Make sure they line up!

Step 10: Install Battery

Connect the battery to the socket labeled "BATT" on the solar charger circuit. Then place the battery between the two circuits. If there's excess space, pad it using double-sided tape, a wad of paper, some chewing gum, large gob of ear wax, or other suitable materials.

Important note about Lithium Polymer batteries:

While safer than standard Lithium Ion batteries, Lithium Polymer batteries may be damaged and even combust if misused. To avoid damage and/or injury, observe the following precautions:

1. Only charge the battery using a Li-Ion/Li-Poly charger (such as the one included in the kit)
2. Never pierce or puncture the battery pack's aluminium casing
3. Do not short circuit the battery
4. Do not overheat the battery
5. If you notice any swelling in the battery pack, immediately disconnect if safe to do so, or otherwise move to a location where there are no flammable materials.

Step 11: Attach Top Cover

Remove the blue protective cover from both sides of the top plate. If it doesn't peel easily, scratch the edges until it starts to peel. Then screw it onto the battery pack.

Step 12: Odd Bits and Stuff

I have a screw loose!
Don't worry, you didn't miss anything. We include one extra screw as a spare.

What's this black block?
That's a jumper, and it's used to upgrade one of the USB ports at your discretion.

How do I get rid of these smudges?
The bottom plate (and all the other enclosure parts) are laser cut and etched (we do it ourselves at TechShop!), and the laser etching process sometimes leaves this tacky residue on the surface. You can remove it with diluted vinegar.

Step 13: Charge Your Device!

The battery packs should already be about half-charged. Try plugging in a device  to the USB port to see if it charges!

Which port should I use?

Most Apple devices (iPods, iPhones, iPads) will only work from the USB port labeled "i-devices". Other devices, however, may also work from that port.

Upgrading the "USB 2" port

Some devices will charge (or charge faster) if you upgrade the "USB 2" port to what is called a Dedicated Charging Port. For example, some devices like the Palm Pre and Verizon MiFi will not charge at all from the stock USB 2 port, but will charge if upgraded to a DCP. Read this article for more info.

Step 14: Test Solar Charging!

Test the solar charging functionality by plugging in your solar panel into one of the two DC ports (doesn't matter which) and placing the solar panel outside. If the red and amber lights come on, that means it's charging!

Some things to know:

* Solar panels work best in direct sunlight with absolutely no shadows
* Solar panels generate the most power when pointed directly at the sun, as opposed to at an angle
DO NOT leave the battery pack exposed to direct sunlight. Place it behind the solar panel as shown in the photo.
* Solar panels may work through windows, especially old windows. However, modern "Low-E" glass (also used in cars) block a lot of energy.

Related reading:
* What do the LED indicators mean?
* Notes on using two solar panels

Like us on Facebook to stay up-to-date! 



    • Tape Contest

      Tape Contest
    • Gardening Contest

      Gardening Contest
    • Trash to Treasure

      Trash to Treasure

    31 Discussions


    6 years ago on Introduction

    Nice job. How much was the kit? (I tried looking on the website but it wouldn't display the price.)


    7 years ago on Introduction

    Just got the kit and it works great! Any hints/ideas on waterproofing the panels? Wrap them (and the soldered connections) in saran wrap?

    1 reply

    Reply 7 years ago on Introduction

    A dab of epoxy on the exposed bits will waterproof it just fine (and reinforce the solder). A slightly fancier alternative would be to use something like Sugru.


    7 years ago on Introduction

    Can you buy two battery packs (full kits) from your site and link them together? Charging both from the same solar panel, or panels? Something like output to input via cable?

    1 reply

    Reply 7 years ago on Introduction

    Yes! All the parts you need to build a second battery pack can be purchased on our site, and you can indeed charge one battery pack from another. However, to do that, you'll need a USB to 2.1mm/5.5mm DC plug cable which we don't currently sell, but you can find one online for a few dollars (or make one yourself).

    Send me an email at and I can give you a discount code if you decide to go this route.

    I am part of the windowfarms open source community . Windowfarms just raised a quarter million bux on kickstarter. Anyways, they use aquarium bubble pumps to airlift water anything from 3 to 10 ft high through their hydroponic "windowfarms". This is typically powered by ac current. There are dc versions of the bubble pumps available but they are rarely used. (I think they use 2 or 4 double A batteries.) If you could power these bubble pumps or reliably recharge them with your device, it would appeal to many of the windowfarmers. Many of them would really jump at this. The project leaders are big into cutting their carbon footprint so it would appeal to them too. So
    I did a test to try to find the limits of this weak airlift technique and I pumped easily 13 ft high without finding the limit! This means that your thing might have applications as a cheap well pump in 3rd countries if it powers a bubble pump with solar and DC. Another guy got 16 ft without finding th limit.
    My experiment is at The airlift pump nano is based on a suggstion from Eileen (who is one of my youtube friends and who was mentioned in a ted talk by Britta Riley of windowfarms. )
    So if you show your device pumping water higher than 16 ft by airlift as per the experiment, you might have some extra business!
    Sorry for being long winded.

    1 reply

    Neat! My kit can comfortably support up to about 1.5A (7.5W) of output, so it might be able to power a small pump. I'm not familiar with bubble pumps, but I'm guessing most of the heavy lifting is done by bubbles? Either way, if it could be powered by AA batteries, it sounds like there's a good chance my kit would be able to power it.


    7 years ago on Introduction

    Congrats on a nice instructable and a great product. Having watched you put together this kit, I can attest to the fact that it is very well thought out. It would make a wonderful gift and "starter" project for someone interested in solar energy.


    7 years ago on Step 14

    a quick remark regarding 'three leds=overheating' ... since you probably will never be monitoring the device at all times, a cheap piezo buzzer would be a cool addition.

    i will try something when i receive my kit :)


    7 years ago on Introduction

    Is the batter pack available to common consumers seeking replacements or are they spec'd for your project and a "one of" type thing. Will users have to come back to you for replacements? What do you expect as a useful life for the battery?

    4 replies

    Reply 7 years ago on Introduction

    I have replacement batteries available for sale, and are priced much lower than other sources. For instance SparkFun sells a 6000mAh battery for $40, while I sell mine for $25.

    But, as you point out, you won't be able to buy the exact same battery pack from other sources. However, you could replace it with any other 3.7V LiPo/Li-Ion cell that fits in the enclosure and has a JST PHR-2 connector (which is pretty common).

    As for the lifespan, LiPo battery packs will retain approximately 80% of their capacity for up to about 1000 recharging cycles, but there's a lot of variability so I don't think that number is very useful. Since my kits come with 6000mAh batteries (which is about 4-5x the capacity of most cell phone batteries) it'll still give you a useful amount of capacity even if it deteriorates to 50%. Many commercial products in the same price range only come with 3000-4000mAh to start with.


    7 years ago on Step 7

    Instead of using the provided wood type screws, I would recommend on swapping them out with machine screws with nuts. While it might be tricky to get the nuts in there, you would end up with a better secured board.

    1 reply

    Reply 7 years ago on Step 7

    Thanks for the comment... just a quick clarification:

    I would encourage people to assemble the kits using the supplied parts first. In reality, the metal screws included in the kit do a pretty good job of securing the boards. The screws are actually slightly larger in diameter than the screw holes, so the threads bite into the soft metallic lining of the screw holes. Once assembled, the boards shouldn't wiggle, and should not pop loose even if the battery pack is dropped.

    Would using a machine screw and nut be *more* secure? Absolutely. But most people probably won't need to swap out the parts from the stock configuration.


    7 years ago on Introduction

    On step 2, between 6 & 7, I'm thinking there should be something along the lines of recommending that the pieces should be clamped or taped until the glue is set. Sanding after the glue is set is a good idea too if you used a wood glue.

    On step 4 and 5, I would probably use some painters tape on the bottom and top pieces so that when I glue in the USB and DC port panels, I guarantee I won't accidentally glue them to the top/bottom pieces. Once the glue is set, I could temporarily remove the top/bottom and remove the painters tape for a perfect fit.

    On step 7 and 8, you write on 3 to secure the screws. Looking at the images, it appears you have wood screws directly tapping the circuit boards. Wouldn't it be better to use a machine screw with a nut (and maybe a nylon washer)? You designed it, so if you say the screw fits well I'll take your word for it! :-)

    That's all my comments right now, hopefully I'll have a lot more when I receive my kit!

    2 replies

    Reply 7 years ago on Introduction

    Thanks for your comments! I think those are all great suggestions. I tried to keep the process as simple as possible, though, I think there are ways to improve it. Perhaps you could post your suggestions as comments on the specific steps, so people can see them as they're going through the instructions.

    As for the choice of screws, I think machine screws with nuts would definitely be more secure, but I was worried about people dropping tiny nuts into exposed circuitry and risk shorting something. Perhaps that's not really an issue since the circuits shouldn't be powered until the end... I'll look into this for future revs.


    Reply 7 years ago on Introduction

    Wow, I always viewed Instructables in "view all steps on one page" and never realized you could comment on each separate step. I've added the individual comments to the steps so others could see them.

    I'll probably replace those screws on the kit I receive since I might end up modifying it a bit. Thanks for putting this together!