I have multi-purpose silicone lubricant spray that I use on flashlight threads.
I wonder if it is safe to use it on the battery contact points or other electrical components.
I live in asia where heat & humidity is high, especially when I live near beach area, and I always find some corrosion happens quite fast when I leave some equipments unused for some time. I’ve used silicone spray & grease on the battery contacts several times, and it seems to work fine, but I wonder if it could cause problem in the long run. Or do I need special lubricant ?
Keep silicones away from switches. The arcing in switches turns silicones into nasty substances that degrade the contact points
Which spray is it? You can use silicone grease but it is an insulator, so you will need to remove it when you want to use the charger or it will inhibit the connections.
Another idea (less messy) is to store your charger in a ziplock food bag with a sachet of silica gel.
I use this :
http://www.amazon.com/CRC-05074-Silicone-Multi-Use-Lubricant/dp/B000BXKZUG
I sprayed some on battery contact, and it doesn’t seem to cause problem with the flashlight. But perhaps I’m wrong ?
Jetbeam Silicone grease seems to cause black gunk on my threads, whether anodized or not, and I hate it.
So, I recently try to switch to silicone spray which seems to dry & leave a thin film on the surface.
silicones are OK to use on battery contacts and no they won’t increase resistance. the battery contacts will push away the grease and you’ll still get metal-to-metal contact. just like when you put grease all over your car battery’s posts when you tighten it down the car will still start 
but most good flashlights are sealed so you don’t have to worry about corrosion so applying silicones isn’t gonna solve a problem that isn’t there. but will be very messy. and as i’ve said silicones creep very well so they could get into switches and cause problems
thank u. Got all the information i need.
The use of an inert silicon based dialectic grease is often standard practice in protecting terminal block contact points from corrosion in many applications. The worlds best marine grade butt connectors and crimp terminals have them filled with it from the factory. I use it for everything from o-rings, automotive block & bus connectors, marine application cannon/amphenol connectors, to flashlight battery contact points. As mentioned, not designed for switch contact points and your results may vary depending on the contact surface area and power conducted. An electric utility company employee tells me they go through the stuff by the ton. You can find it in a small tub/tube of paste at any good SCUBA or camera shop, usually sold as o-ring lubricating paste.
+1, Im also a fan of CRC products.
Edit: I like this one because its not a spray, but a pressurized can than slowly dispenses a bead of silicon with precise control.
I use Jetbeam grease too. The black gunk can be caused by contaminants mixed with the grease. It’s best to clean the threads before applying a new grease to threads.
I don’t like putting silicone products unless really necessary as it is quite difficult to remove completely. Sprays ike the CRC-05074 have acetone which is not nice to some plastics either, but you could use a cotton bud to apply it to the metal.
At the auto parts store too, or even the GM dealership. The stuff is frequently used to keep weatherstripping supple.