Usually it has been seen that people who use laptops actually plug the laptop to the power supply. However this lithium facts is the wrong way of charging the battery. You should charge a battery once or twice a month. The battery should be charge fully at least 30 minutes before you start using it. In case you are going to use direct power supply, then it is best to remove the battery. This will ensure two things -- first, the battery since it is charged already will not discharge uselessly and second, it will ensure that the battery life is extended.
I run a PC repair business in Vancouver. I always tell people who call with clock problems to check their motherboard battery first before calling me round. For most people it's easy to lithium facts check and easy to replace. I don't want to make money from fixing something so simple.
The last thing to start tinkering on is the rate of fire. The biggest thing that will determine your ROF is the battery voltage and the amount Milliampere-Hour rating (mAH). Some of the best batteries for increasing ROF are the LiPoly batteries (Lithium Polymer) but you should not use these types on out of the box guns. When preparing to use the Lipoly battery you need to make your internal components are reinforced and upgraded where they need to be.
Also keep in mind that when your iPod mini battery does die, it requires a proper funeral inside a proper container. No you don't need to buy a casket and a plot but you do need to adhere to local lithium bettery stock laws when it comes to battery disposal.
Briefly relating back to overall size... many lithium 18650's will differ ever so slightly in length (measured in millimeters). This is mainly due to an added protection circuit. The circuit helps to prevent the battery from over-discharging, since Li-ion cells can easily become damaged if their power is drained below a particular voltage. The protection circuit also prevents the cell from being over-CHARGED as well. These cells are very sensitive. They must be handled carefully, gently, and as described above, must never run-down too far, or be charged over and above their threshold. They can actually explode if severely mistreated!
For jobs where the batteries are required to be light weight as well as being reusable, then lithium batteries are ideal. But if a battery is needed to be very reliable or to remain unused for a long time then they might not be the right batteries for it.