DIY 23.000MAH Li ION 4S 16.7volt BATTERY FOR less then €30
step 1 get 30 dead or old stock laptop batteries
step 2 Take the batteries appart and split them into single cells.
You should have about 100 cells from dead laptops to make a 40 battery high capacity high quality field charging battery.
step 3 Charge all the cells individually
Step 4 Discharge all the cells individually and write down the amount of power they provided on the discharge cycle
Step 5 Charge all the cells and weight a month to see whether the batteries have a short and drained down to 0 volts again. Throw bad batteries that are dead or that have very low capacity away. this should be around 20%-40%
Step 5 Design your battery
Step 6 Build your battery with the proper hardware.
Further recommendations: This battery is like a small welder, make sure to take proper safety measures into account and never leave charging batteries alone. These 18650’s produce allot of power and can start fires when they short cirquit. The battery does not explode but the material that creates a short circuit gets very very hot and starts fires. make sure to put your design on paper and calculate the exact capacity of every parallel cell. They have to be all the same. Make sure you use a proper charger and handle the battery with care.
every battery can deliver 2-3 amps. My battery is 40 cells arranged in parallels of 10. so 4*4.2V=16.8V. This battery can deliver only 30 amps for longer periods of time. The batteries get damaged when you draw much more current.
Li-ion cells don’t get damaged when stored over longer periods of time at full charge only slightly. This battery can start your car (it can deliver very nice amp spikes) it can weld thin metal so be careful.
Uses for this battery:
It can power an electric skateboard,
It can start a 16V car.
It can be used for field charging with B6A2 chargers
It can be used for electric bycicles (search for rinoa super genius)
It can spot weld thin metal (or blow holes in it)
It can start a fire
It can be safely handled
It can be balanced charged ONLY
Have fun XD
Ebay old batteries:
18650 charger chips USB:
ABS Battery holder:
Heat resistant tape: