Lithium-ion (Li-ion) batteries are inarguably the most popular type of rechargeable battery for consumer electronics. They can be used for a variety of products from mobile phones to cars, and their qualities are superior compared to other rechargeable batteries.
At NightSearcher we use high-quality lithium-ion (Li-ion) batteries for all but a few of our rechargeable flashlights, searchlights, head torches, and floodlights, as they allow us to provide the high-performance, durable products our customers are used to.
Below we’ve listed the biggest advantages of lithium-ion batteries from the customers’ point of view and delved into the science behind each characteristic.
Lightweight and compact:
High energy density = A bigger punch:
Lithium is a highly reactive element with the ability to release and store large amounts of energy, allowing li-ion batteries to pack a high energy capacity in a small size. This translates to lithium-ion batteries lasting much longer between charges than other rechargeable batteries, while still maintaining their high level of performance.
A typical lithium-ion cell (= battery) has an average cell voltage of 3.6V, whereas a nickel-metal hydride (NiMH) cell averages at 1.2V, meaning three Ni-MH batteries are required to match the output of a single lithium-ion battery.
Older types of rechargeable batteries, such as nickel-cadmium or nickel-metal hydride batteries had a so-called “memory effect”, or “lazy battery effect”: If they were repeatedly partially discharged before being recharged, ultimately the battery would only deliver the amount of energy that was used during the partial discharges before its voltage would drop. To avoid this, NiCd and NiMH batteries would need to be regularly maintained by completely discharging and recharging them.
Lithium-ion batteries don’t suffer from the memory effect, which means they always give up their last bit of power, and you can recharge them whether you’ve used 100% or 25% of their capacity with no pesky maintenance needed!
More charge cycles:
Quality lithium-ion batteries last about a 1000 full charge cycles. A full charge cycle is when the battery is discharged to flat and then recharged to full, so using your battery until it’s at 75% capacity and then plugging it into recharge doesn’t constitute a full charge cycle. When your battery has recharged back to full, you can still use the 75% of the capacity that you were left with before you recharged your battery; only then has your battery gone through a full charge cycle.
Low self-discharge rate
Lithium-ion batteries also have a relatively low self-discharge rate. Self-discharge is a natural, irreversible phenomenon for batteries, where chemical reactions inside the batteries reduce their capacity even when the battery is not being used. The self-discharge rate of lithium-ion batteries peaks at about 5% within the first 24 hours after charging the battery, and then tapers off to 1-2% per month. In comparison, nickel-based rechargeable batteries lose about 10-15% of their capacity after charge and another 10-15% per month.