The modern world as we know it wouldn’t exist were it not for batteries and the unique, utterly essential ability to store electrical energy that they provide. Without 18650 batteries, there is no such thing as mobile.
Sealed Nickel batteries are the most common form for consumers and don’t require much in the way of general maintenance to continue operating. However, there is still much you can do to keep it operating at peak performance. NiCd rechargeable batteries, for example, can be charged at varying rates depending on the cell’s construction, ranging from 14 hours down to just 10 minutes. However, as the amperehour rating increases, so too does the internal resistance which generates heat and slows the electron transfer and the chances of overcharging which again generates heat and can actually damage the cell and shorten its operational life. Since NiCd batteries will heat up more as they near full capacity, you should invest in a compatible charger with a temperature gauge automatically shuts off the current flow when the battery heats to a certain degree, preventing an over-charge.
NiCd batteries also tend to self-discharge, though not to the degree of NiMH batteries, typically just 10-20 percent a month, depending on the temperature. As such, if you need to store a NiCd battery for long periods, you’d do well to first run it down to below a 40 percent charge before placing it in a cool spot. Some battery makers even recommend fully expending the battery and then short circuiting the leads for long term storage as well, so make sure you check the website for additional information before doing so. Even when they are not about to be packed away, NiCd batteries do well with the occasional full discharge in order to prevent memory effect, once every 30 cycles or so should do it. If these steps are followed, NiCd batteries can last as long as five years in storage. NiMH batteries, on the other hand, will last about three years but do require priming beforehand.