12"x12" Flexiglass Clear in 5mm thicknes
Soldering Iron 30w
Red & Black wires ( for electronic)
Mighty Bond (quickdry epoxy)
Vinyl floor tiles (new) 1pc only-i used excess spare from other projects made before.
USB step up pcb 3.7 to 5v dc
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Step 1: Cutting FlexiGlass
Using rotary power tools is a big advantage,.But i dont have it as of now,but planning to have soon.
And yes,i did it doing the old school method of cutting flexiglass,.im doing this since.,for starters,make a layout directly on flexiglass using pencil initially,.then slightly mark all the layout using exacto knife,.to avoid erasures of the layouts pattern.then score the pattern layout both sides of the flexiboard,.leaving deep marks enough to break it apart accordingly to your pattern.
Then bond them together using quickdry epoxy.
Step 2: Plan
Plan all the necessary components needed for the project,such as the USB step up circuits,switch & 18650 batteries.
Then arrange it the way you want it.,placing it on top or in its either side of the case.
My initial plan was to use a Car USB adapter with 2 USB discharge port that can charge to devices at the same time.,thats why i end up building a case like this,.but i changed my mind.,i got a source,that offer 2 pcs of USB step up,wth charging/discharging port + 3 18650 in 2200 mah per battery + 2 powerbank new cases.,i grabbed it for only P500 for the all the set of stuff.,So,the case was too big for the chips im going to use,.anyway i finally decided to move on the project doing no alteration with the flexiglass case anymore.
Step 3: Installing Components
Preparation and installation of the components such as USB chips,Switch & Batteries are very important.,thats why creating a pattern layout i a must instead of directly putting it together,.that will end up on more errors in installations.
Step 4: Battery/Wirings
Battery connections are very easy,i used of course the Parallel connections as required by the USB pcb specs,to achieve the desired mah capacity,& to gain a fixed 3.7v
See the picture how battery works.
•wirings are not so difficult too.as seen in Battery works image.You'll just end up with two wires..Red is the Positive +. And Black is the Negative -
Connect the Red + wire to the 1st terminal of the switch ,then solder another Red wire on 2nd terminal of the switch that will be connected on
B+ terminal of the USB chipset,then the negative Black wire from then battery will be soldered on the B- Negative terminal of the USB chipset.,Thats it.,its all done.,Double check all youre wire connections,if everything was right,.You can switch on or fire up the switch,.Use Multi tester if in doubt.,connect it using the USB cable that came with your device or phone connect it & switch on,.if the Led blue light emits that means it is discharging its juice to your device.Then test the micro usb charge port using your phones charger,if Red Led light emits,.that means its charging the batteries.,Almost done.,lets go & run some test.
Step 5: Run a Test
Red light -charging PBank batteries
Blue light- recharging devices
•Blue and Red light will auto stop when it meets battery full charge state.
•Powerbanks like this are compatble to any device with USB compliant.
Step 6: Test Results
I closely monitored all the tests and indeed the result was achieved,.This DIY project was really satisfying,The new 18650 batterries i bought was a Real Capacity of 2200 mah/battery,as promised i fully charged it first for 9 hrs,Since each 2200 mah bat requires 3 hrs to fully charge.,And it did successfully full charge my iPhone 3 times,.i usually charge my iphone when it reaches low batt status Of 20%...,.And this project do what i expected.
I hope this project help those who want to build their own Powetbank.,without the need of expensive powertools.
Facts to Share:
•How long do I need to charge the powerbank for the first time and subsequent time?/ How many times can a powerbank charge my phone?
a) powerbank is already pre-charged and ready to use.
b) Re-charging time depends on the capacity of the powerbank, remaining power in the powerbank and the power supply.
-Powerbank: 13000mAh (0% remaining)
-Power Supply/ Input: 1000mA plug
-Calculation: 13000mAh/ 800mA = minimum 16.25 hours
(Why 800mA? An estimate of 20% power is consumed during the charging/ discharging process)
c) Similar formula applies to calculate number of times a powerbank can charge a phone.
-Powerbank: 10000mAh (full at 90%)
-Phone Battery: 1500mAh
-Calculation: (10000mAh x 90% x 80%) / 1500mAh = up to 5 times
(Why 90%? Assuming the power bank is well maintained in good working condition and can conserve up to 90% power)
(Why 80%? An estimate of 20% power is consumed during the charging/ discharging process)
* Note that the calculation is based on normal condition whereby the powerbank or device (phone/ tablet) is not in use during charging process. A running device generally consumes power therefore if your device is actively in use during the charging process, the charging performance may not meet the expectation.
* The above calculations are examples made simple for easy reference. Accuracy may vary.
Step 7: Upgraded
Upgraded PowerBank link: