Question about Li- ion batteries

[diverdarren]

My question is regarding the new energizer batteries called "ultimate lithium". Are these batteries safe to use in a dive light? One of my dive buddies told me that he thought that this is not a good idea because of the possibility of flooding and water contacting the lithium and causing an explosion. There is no warning about water contact on the battery packaging. The life of these batteries is amazing, but I don't want to end my cave dive with a bang.

[apitkin]

It's not metallic lithium. It won't explode if it gets wet. These batteries are quite safe to use underwater.

Andy

[diverdarren]

Thanks for the good news, Andy. I had been using them in my little Intova that holds three triple A's until my buddy mentioned this,then I took them out until I could get some info on them. Regular energizer batteries seem to have a short life in this light but the lithiums last much longer(the manufacturer claims up to 8 times longer in high tech devices like L.E.D. lights).

[Bobby]

There are a couple of down sides to using Lithium disposable batteries in place of Alkaline. First is that they drop off in power much quicker than Alkaline. They will last longer and give you good burn up to their useful end then drop off very fast to no light output. This combined with the second issue of not holding full charge as well as Alkaline can leave you in a bad spot when you need them the most. I am assuming you are using them in a backup light. If using in a primary then it is probably not as much of a concern as you will have backup lights in case you burn through the primary.

[diverdarren]

I have been using L.E.D. dive lights for several years and it seems to me that the drop-off problem is really more attributable to this type of light because you don't notice that the light is beginning to dim until the batteries are almost completely spent.

[a64pilot]

Some light drivers will decrease the current going to the LED's as the battery weakens in order to protect the LED's. I don't know if this is true of flashlights or not.