Did you know that the rechargeable lithium-ion batteries in your portable charger age over time? Over time, as you continually charge and recharge the batteries or drain and refill them, the capacity of your portable charger will begin to decrease. Typically, in the first year of normal use, lithium-ion batteries should remain at around 100% of their stated capacity. However, certain environmental conditions and ways the batteries are used or implemented can shorten the expected lifespan. In this article, we discuss some of the precautions ZMI has already taken with our battery products. We also provide some tips and recommendations for our customers.
When you unpack your PowerPack or Plugornot portable charger and take it out, you soon discover that the battery level (as shown by the indicator lights) is at around 50%. Of course, that might seem a bit odd. Shouldn't the charger automatically be charged to 100%, so customers can take it out and start using it immediately?
The reason why we ship our battery packs at around 50% capacity is not only for safety reasons, but also to extend the shelf life of the battery. If lithium-ion batteries are stored at 100% charge for an extended period of time, they will suffer from reduced capacity and a shorter lifespan. By storing them at 50% capacity, we ensure that when our customers receive their portable charger, the batteries are still good as new. Our tip to customers with ZMI battery packs or any lithium-ion battery product or battery-containing product is that for long-term storage, make sure to keep the batteries at around 40-50% charge.
Environmental conditions also affect lithium-ion battery lifespan. Specifically, high temperatures of 25℃ (77℉) or higher will reduce the battery's capacity. Of course, extremely low temperatures, while not as harmful as high temperatures, should be avoided as well. Our tip to customers is to avoid charging and recharging (cycling) the battery in extreme temperatures. More importantly, it is important to store the batteries long-term in moderate temperatures, anywhere around 20℃ (68℉) would help extend the lithium-ion battery's lifespan.
TL;DR
You should keep the battery pack's charge level at around 50% for long-term storage. When charging and recharging, make sure the surrounding temperature is below 25℃ (77℉).