2days back I opened my cousin brothers laptop battery as it was a spare one left unused over a year. I disintegrated it and found 6x 18650 batteries when I checked them with voltmeter individually I found that 2 were dead I.e.0V and 2 read 2.15 V and the last two read 1.5V. I thought of making a power bank using them individually. The battery are ideal for a power bank because they have 2200ah capacity. I need a circuit to charge it. I thought of chraging it with arduino. But how? To get the datasheet just search "lr1865ah" in google and click the one and only pdf link that is the cell's datasheet. I need the charing circuit using arduino.
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22.15v is way too low. The cell might be damaged due to this. Damaged lithium cell can burst into fire. I personally wouldn't risk it. Just toss them in the trash.Gerben– Gerben2015年04月15日 15:16:23 +00:00Commented Apr 15, 2015 at 15:16
1 Answer 1
There is a far easier (and safer) way to charge them without using an Arduino. Over-voltage is an issue and another crucial factor with the 18650 batteries is to not let the voltage drop below 2.5 volts when you are dis-charging them. There is a simple "Charge/Discharge Board Module for 18650 Lithium Batteries" that sell for approx. 1ドル US:
The board has a "fast charge" current of 1000 mA until the battery reaches 4.2 volts, then it switches to a "trickle charge mode". The circuit board also stops current flowing out of the battery once the voltage drops to 2.5 volts. Most of the older charger boards do not have this feature and it's almost as important. It also has a "over-current" protection current of 3.0 amps in case you try to draw too much power from it.
The circuit board has a mirco USB connection on it but be VERY careful before you plug it into a computer USB port. My old MacBook only provides up to 500 mA at each USB port, half of what's required.
The circuit board is 0.700" X 1.050". Here is a picture of it:
