Cordless Drills are wonderful tools. Almost everybody from professionals to home improvement DIY hobbyists use them. When this tool stops working it's a nightmare because the work is interrupted. And oftentimes the problem is that the batteries are no good anymore.
 

When fired point blank, plastic BBs can hurt as much as rubber bullets, however most people engaging in military simulations with airsoft guns wear thick military garb. Additionally, precautions are taken to protect the neck, face, and eyes. Many people chose to wear a balaclava around their face and neck and cobalt ontario ANSI approved eye protect is a must. The only place that plastic BBs can really cause damage is to your eyes.

The battery will over-charge if left attached to the charger. The battery stops charging automatically when full lithium facts so it will not over charge. If the battery is left on charge too long it is possible that heat will damage the battery.

This can be a problem for where the battery is not used that often but is can be important when it is needed for emergencies such as power outages. As the battery does not store well over extended amounts of time, it is possible that when they are needed they will not be usable. But for things that are used and recharged on a regular basis such as for portable electrical equipment, they are very good. But there is not always a slowing amount of capacity when they are getting old and it is possible for them to just not work without any reason being obvious.

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!

Step 4 - Connect in the newly bought battery to the board of the iPod (where you unconnected the old battery) and set it on the glue that remained on the hard drive. Make sure that the battery and the wires are set properly so you can actually close the iPod. Snap the cover back together, you'll hear it when it's finished!