Lithium-ion (Li-ion) batteries are rechargeable and are increasingly being used in many electrical appliances,replacing their forerunner,the nickel-based battery.The reason is simple: Li-ion batteries produce a nominal voltage of 3.7 volts compared to 1.2 volts from a nickel-based battery.Additionally,the milliamp hour (mAh) that can be drawn from a Li-ion battery is approximately three times the amount that can be drawn from a nickel-based battery.A Li-ion 18650 battery is the same size as a regular AA alkaline battery and generally has a nominal rating of 2,000 mAh.If you want to check that your Li-ion battery is in good condition,test it for voltage and the milliamp hour using a multimeter.
Look at the multimeter display panel.It should read between 3.6 and 3.7 volts if it’s in good condition.If the battery has just been charged,the reading may be up to 4 volts,but this does decrease to 3.7 quite quickly.If the reading is below 3.5 volts,charge your battery until it is full.Let it rest for a few hours and then test the voltage again.If it remains below 3.5 volts you need to consider getting a replacement because this indicates it is losing its charge.Check the milliamp hour using the multimeter.Set it to measure the milliamp hour and put the two metal rods from the multimeter onto the positive and negative battery terminals as before.
Check the label on the side of the Li-ion 18650 battery to confirm its output.The voltage should read 3.7,but the milliamp hour may be greater or smaller than 2,000 (some are 3,000 mAh).Find the terminal polarities of the Li-ion 18650 batteries.The circular raised button on the top of the battery is the positive terminal and the flat plate on the base is the negative terminal.Check the output voltage using the multimeter.Ensure that it is set to measure volts.Put the small metal rod on the end of the red cable from the meter onto the positive terminal of the lithium battery 18650.Put the metal rod on the end of the black wire from the multimeter onto the negative terminal of the battery.
Check the multimeter display.A fully charged Li-ion 18650 battery in good condition measures the same as the milliamp hour printed on the battery label.Milliamp hour measurements drop as the battery discharges energy during use,so if the reading is more than 5 percent below the milliamp hour on the label put your battery on charge until full.Test the battery again.If the milliamp hour is still more than 5 percent below the milliamp hour on the label,consider getting a replacement as the battery will not power your electrical equipment for the correct amount of time.
You can test the strength (power left) of any battery you own with this device.It’s extremely handy and costs very little.It’s one of the things many people don’t ordinarily think of buying but even if you only use it occasionally,you’ll sure be glad to have it around when you need it.Let’s say you’re planning to be away at an all-day event where you know you’ll be inclined to take lots and lots of pictures.Wouldn’t it be better to test a few batteries before you leave to know which ones are full of power and just take them along?It sure would!The nimh batteries testers (all chemistries for that matter) are good for battery sizes: AA,AAA,AAAA C,Sub C,D,and 9 Volt for very nominal prices.