How long do 18650 batteries take to charge？

A 18650 battery is a lithium-ion (Li-Ion) rechargeable accumulator, which is almost always cylindrical.

18650 battery first charge

Charging your 18650 battery for the first time can be slightly confusing. When you receive your battery, it is best to do a quick top-off charge before use. Then, when you are ready to use it, take note of the LED indicator light on the charger and unplug your battery as soon as that light goes out (indicating that charging has stopped). This initial charge should take about an hour, so be sure to keep the battery in the charger long enough to ensure that it is properly charged.

How to discharge 18650 battery

Step 1: Set up equipment

• connect the multimeter in series with the battery to be discharged.
• does not matter which terminal goes on positive and negative, just as long as you don't reverse polarity. (red probe attaches to the pos terminal, black probe attaches to the neg terminal)
• increase voltage scale so that it can measure at least 5 volts (or as high as possible, up to 7.2 volts)
• make sure all equipment is properly grounded.

Step 2: Set multimeter to discharge

• set multimeter to "200 milliamps or higher" (most will be 500mA) DC mode by either hitting the appropriate button on the multimeter (if it has one) or by setting the multimeter to DC voltage and then back down to the desired "200 mA or higher" (most will be 500mA) on the dial.

Step 3: Discharge battery

• slowly decrease current (on the multimeter) until it reads 0.2 volts