The Personal JukeBox's rechargable lithium ion battery is estimated to allow 10 hours of play after a full 3-hour charge.

Built-in rechargeable lithium ion batteries, lasting more than 24 hours in normal usage.

Balancers are often found in Lithium ion battery packs for cell phones and laptop computers.

Several people have successfully documented replacing the built in Lithium ion battery with a higher capacity battery, increasing time the T3 can be used without charging.

However, before lithium ion batteries could be mass-produced for widespread use, safety concerns needed to be addressed such as overheating and over potential.

Lithium ion (LiON) batteries offer still higher energy density.

It accommodates two large-cell lithium ion battery packs.

Removable lithium ion battery.

But even the best lithium ion batteries are drained eventually.

A fully charged lithium ion battery will do the job for just 150 hours.