Reusing Old Phone Batteries As a Power Bank

Probably majority of the worlds population owns a smartphone and also probably had more than one during the past few years of smartphone evolution.

But with them, come used lithium ion batteries that you can not just keep on using inside your new phone. So in all if the battery is dead then we are stuck with useless batteries. But we also got a way out of it. We found out the way how we can reuse our old phone batteries. Because average lithium battery has 80% of its original capacity left after 2 years of usage which is the period in which I usually buy a new smartphone (not because of the better specs but because of major hardware issues).
And think about the energy that went in to extracting the raw materials, producing the battery and shipping it.Considering all that it would be a real shame to just let them slowly die or throw them away.
So here we present you some steps through which we can build a device that enables you to reuse your old phone batteries as a power bank for newer devices.

STEP 1: MATERIALS

Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

Here are the materials that  we will  need for to build your own recycled power bank:

• a used lithium ion battery
• a lithium ion charging and protection board with 5V 1A max. input ( less is more in terms of battery life)
• a 5V DC step up converter with 600mah max. outpu t (")
• some wire
• a few Arduino pins and slots
• a paper clamp
• some leftover acrylic and screws and a switch

The required working equipment consists of
• a knife
• a pair of pliers and a wire cutter
• a soldering ion
• a hot glue gun and  a drill or dermel tool.

STEP 2: HOW DO THE BOARDS WORK?

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Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

The lithium ion charging and protection board has three important functions.
The first is charging. Lithium ion cells have a certain charging pattern. When they are nearly full, their current consumption drops. The board will r ecognize that and stop charging as soon as the cell voltage reaches 4.2V.
On its output the board features a protective circuit consisting of an over current and an under voltage protection. Such a protective circuit is already integrated in modern phone batteries and therefore not necessary but it will allow us to use unprotected cells like we would find them in old laptop batteries as well. The charging current of the board can be adjusted through a resistor. It should be somewhere between 30 to 50% of your batterys capacity.
The DC converter takes the dc voltage from the battery and turns it into a square wave that is send through a little coil. Through inductive processes a higher voltage is achieved. It is converted back to DC and can be used to power 5V devices.
Now lets start making .

STEP 3: PLANNING

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Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

Before we begin to make the enclosure, take your measurements and make a plan.
My device is supposed to be held in place by the paper clamp, so it will be bolted to the enclosure. The two pcbs will sit on top of each other with the in- and output at the top and the battery pins at the bottom.
Some phone batteries tend to have a different polarity than others, so the device needs pins with interchangeable polarity. To add this type of functionality we used the Arduino pins a nd slots.4A piece of three slots with the middle metal connector ripped out and the 2 outer ones bend to the side can be used as a battery connector.
The counterpart will be a row of 4 pins with positive wires connected to the outer two and a negative wire connected to the two in the middle. This way the polarity can be changed by plugging the battery connector in on either the right or the left side.

STEP 4: MAKE THE ENCLOSURE PARTS

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Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

Image Source - Geek Winky

Time to make the enclosure. For this we use our measuring tool to find the right with and use the knife to scratch the surface about ten times. Then we can keep in without the measuring tool and more force. When we are about half way through, place our pliers next to the cut and bend the material until it breaks. When all the parts are cut out sand and test fit them. Fix them on a stable surface and start making the holes for screws, switches, inputs, outputs and pins using a dermel tool.

STEP 5: SOLDER THE BOARDS TOGETHER

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Before we can assemble the parts we need to wire the boards. The schematic shows how they have to be connected. The small switch turns the dc converter on and off.

STEP 6: PUT THE PIECES TOGETHER

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Use hot glue to stick the PCBs together and to stick the onto one if the plastic pieces. Glue all the pieces in place and screw the clamp on. 
Plug the battery pins in and test it.
If it does not work, try plugging the charging cord in.

STEP 7: USE IT!

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Image Source - Geek Winky

So now we got a new purpose for our old batteries. The enclosure couldn’t be the best looking solution but its a way put forward a concept through which we can reuse phones dead batteries.

Hope you guys like this awesome trick....
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Article By : Priyanka Mall @ Geek Winky