Now this is a question that might have run through your mind many times. Most mid-range to high end modern smartphones come with lithium polymer batteries while the low end ones usually come with lithium ion batteries. And it is something that we have been observing for a short time only. Earlier there was nothing like a lithium polymer battery and all the devices ran on lithium ion batteries. And from mobile phones, this has crept out to portable external battery packs or power banks as we generally call them. So how are the lithium polymer batteries any different from the ones that say lithium ion in the spec sheet? And if they are different, which one makes more sense for an external battery pack.
These batteries came into existence over a century back though have been in proper use since portable devices started flooding the markets. They don’t cost a lot to manufacture and aren’t very big. The energy density for lithium ion batteries is high so they can hold lot of change in relatively small size. Unlike older nickel based batteries, they don’t require priming before first use either making them more suitable for application in handheld devices. The good thing with lithium ion batteries is that they don’t self-discharge quickly. This means that you can put a charged battery away for long and even after months, it would have a large percentage of its charge left for your use. Though it isn’t all good with these lithium ion batteries. They tend to age and it continues to happen even if the battery is not being used. So it loses its capacity to retain charge over a period of time even when left unused.
Lithium polymer is a relatively newer battery technology as compared to lithium ion but still has been around for quite a while. These batteries can be made into very slim shapes making them more practical for sleek smartphones and tablets. The battery life isn’t compromised even with the slim design so it is a win win situation for smartphone uses. On top of that it can be made into different shapes unlike lithium ion batteries which can be rectangular only. With the increasingly complicated and cramped insides of modern smartphones, lithium polymer batteries can be made in a shape to fit in the leftover space. The energy density of these batteries is lesser than the lithium ion batteries. On top of that they cost more to manufacture and thus don’t make a lot of sense for low end devices.
Which one is better for a power bank?
Now that is a tough question to answer as it will depend on the usage pattern of individuals. Both the battery types retain charge well and have almost similar usable life. Size won’t play a very important role when you are picking an external battery pack. So if you are going to use the power bank very often, you can pick one with lithium ion batteries but if you will rarely use the power bank, try to find one with lithium polymer batteries.