Intro: $1 USB BATTERY BANK FROM OLD LAPTOP CELLS
Hundreds of laptop batteries get thrown away each day. Many still have good cells but cannot be used as the laptop is outdated. So rather than letting these batteries get sent off to a third world country to rot in a pond we can reuse them.
These batteries can be found in almost any computer repair shop. Ask for defective or usless laptop battery packs and they will be happy to give you them for absolutely free.
Or if you have one at home you can save yourself a trip.
This instructable is a different variant of my other instructable where in this i will spend more money and go into a bit more depth on exactly how to recover cells.
Step 1: Sourcing Your Components
This case can be by searching: USB Power Bank Case 18650 on ebay
These old laptop batteries can be found for free at your local computer shop.
Step 2: Extracting the Cells
Stick a screwdriver in one of the seams and pry. The Case should split open however it may not be easy. Cut off the circuit board and split the cells into 3 2 cell parallel pairs. The nickel tabs are pried off. Be careful because these are sharp.
Measure the voltage of the cells. The cells should be over 0.5v anything below generally will have low capacity and high self discharge.
Charge the cells up to 4.2 volts. Let the batteries sit for a while then measure and record the voltage. If the battery voltage decreases after 2 days by at least 0.1 v then it has to high of a self discharge. Also discard the cells if they get hot when charging.
Step 3: Assembling the Powerbank
once the battery is tested to be good it can be inserted to the battery case purchased from ebay.
Open the case, put the battery in and close the case then the assembly is complete.
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