These are 1450mAh AA batteries that recharge directly through a standard USB port.

This is how more digital devices should be designed. I am not a fan of products, such as portable speakers, becoming unusable simply because an internal battery can no longer hold a charge. A replaceable battery design is far more practical than throwing away an otherwise functional device.

At the time of writing, a four-pack of these AA batteries sells for about $35, which comes out to just under $10 per battery.

The manufacturer claims the batteries support up to 500 charge cycles. Even if that number is optimistic and real-world use delivers closer to 250 cycles, the long-term value still makes sense.

They also state the batteries last two to three times longer than standard disposable AA batteries, which is likely tied to the 1.2V NiMH (nickel metal hydride) cell technology used inside.