The trouble with SPOT is that it is both a tracking device that is used on a regular basis (= eats batteries each time you go somewhere, and rechargeable makes sense) as well as an emergency device (= lithium primaries makes sense).

It is hard to fullfil both roles at the same time...

Of course, the logical solution is to carry spare lithiums at all times. Ideally, there should be a separate compartment in the SPOT unit for spare batteries. (Come on, it wouldn't be that hard to design that with only a slightly larger unit!). The trouble with keep2go tubes or similar robust containers is that those can be lost or left at home.


Personally, I hate using primaries for anything other than those "ONLY IN EMERGENCY" devices. If I had a spot, I am sure I would use it as a tracking device on some, but not all of my trips. I would bring spare lithium at all times, but would not hesitate to go against the factory instructions and feed it eneloop nimh when used as a tracking device. If I don't want tracking I'd feed it lithium primaries.


Why do I hate to use primaries? Because if you use them "a little" for two or three times in a row you loose track of how much juice there is left. Is it 70%, 50% or 25%? Unless you throw away a lot of half depleted batteries (a waste!) you never know how much time you have left before you have to change batteries.


With rechargeables (low self discharge nimh, in this case) you just recharge them. Always full - always ready, and you have a pretty good feeling of how long it takes before you need to change batteries.