You Must Discharge Your Batteries Completely Before Recharging Them!

This myth is actually true, but only when it comes to Nickel-Cadmium (NiCd) and NiMH (Nickel Metal Hydride) batteries. These batteries suffer from the memory effect that reduces their capacity if frequently recharged whilst still partially charged. To avoid that, such batteries should preferably be discharged completely before recharging.

However, a little knowledge is a dangerous thing. Many users and even resellers alike are propagating this advice for all batteries, even though it isn't true for lithium-based batteries, the dominant battery technology for the tech sector. In fact, discharging lithium-ion and lithium-polymer batteries completely is ill-advised as it reduces their useful lifespan.

So, if you simply listen to your friends and discharge your lithium-ion/polymer batteries all the time, you are actually sentencing it to an early death! Lithium-based batteries last longest if they are kept charged. In fact, it's good to trickle-charge them.

Unlike nickel-based batteries, lithium-based batteries suffer from a fixed lifespan. The second they leave the factory, these batteries will slowly degrade and lose capacity. How early they die depends on how well they are treated, as well as the temperature they are subjected to.

Although these aren't really related with the myth itself, here are a few tips if you want your lithium-based batteries to last longer :

• Try to keep your lithium-ion/polymer batteries charged as much as possible. You should never discharge it completely.
• If you don't intend to use the battery, disconnect it from the device and keep it somewhere cold. The best thing is to place it in a sealed package and keep it in the freezer where it'll only lose about 2% of its capacity per year. Or you can just put it into a dark drawer. Easy, right?
• The perfect charge level for long storage is around 40%. Although you can store the battery when fully charged, storing it at 40% will greatly reduce the loss of capacity. However, you should never store the battery when it's low or completely discharged.
• Lithium cell degradation starts the day the battery was made. So, unlike the alkaline batteries we tend to buy in bulk because they last a long time, it's better to buy lithium-ion/polymer batteries only when you need them. It’s also wise to note the production date and request batteries that have the latest production dates to get the best bang for your money.