A backing soda solution that is not real wet (but not too "pasty")and a small brush. The mag light is spun aluminum and there are no "electronics" involved. The battery contact in the end cap is made up of the spring and the cap it's self and can be soaked in the solution and brushed clean. The positive contact (bottom side of the bulb holder) can also be removed and soaked clean.

The cylinder can be brushed with the brush well saturated and should come clean with no problem. "Coke" has been used to clean battery terminals for years, but the new formula coke sucks for that purpose and soda works much better.

A laser is L ight A mplification by S imulated E mission of R adiation a flashlight is pretty much a lightbulb that in some cases with the design of it can be amplified They're both alike as they both consist of photons. They're different because the laser only emits one wavelength, while a flashlight emits a mix of wavelengths. They're also different because in the light from the laser all the light waves are emitted in synch(crests and troughs appears simultaneously) while from the flashlight they appear every which way.

Although batteries are better made now then they were before some of them still leak. so when a battery is dead it should be reomoved from the device do that it does not corrode the contacts if it happens to leak. if you leave a device for a long time even a new battery should be removed and only put in when needed because new batteries can leak as well.