You can buy bored Surefire Z2 bodies (or send yours in for modification) from places like Oveready.com or from modders on Candlepowerforums. But upgrading to single cell 3.7V Li-Ion is a bit of work. You need a good charger, quality batteries (AW, Redilast), and then decide on size and chemistry. 18650 refers to the battery measurements BTW, 18mm diameter, 65mm in length, and 0 means its a cylindrical cell. AA is 14500, CR123 is 16340, etc. If you wanna make a quick leap to rechargeables my advice would be to go with LiFePO4 RCR123 batteries. Its a much safer chemistry, they're 3V, which means you use them just like you're using the CR123 primaries you've got now. I've been using Tenergy LiFePO4 batteries and charger from Batteryjunction for awhile now and they're great. The runtime is a bit less but they charge quickly and are very durable. If you're interested in doing some reading at the battery section of Candlepowerforums you can make a more informed decision on what you want to do.

I haven't been over to Candlepowerforums in a while but I might have to check it out. Thanks for the tips.

My Garmin GPSMap 60Cx won't take fresh lithium AAs. The voltage is slightly too high, and it shuts down. If you discharge them a bit, they're OK. It's a pain to have to do that. I basically have a pair of Li AA spares that are more or less dedicated to the GPS.

I use a variety of AAs. Alkalines for cheapness; they get used in low-drain devices like remote controls. Lithium for emergencies and spares, for their long life, lightness and cold-weather performance. Eneloops for day to day use. I have several chargers, including a Maha and ones that will run off a car lighter socket. I also have solar panel chargers that ought to work, although I don't have much faith in them.

I used to prefer diversity too, and I still have some old torches that work on weird batteries, including a Surefire U2. However, technology has now passed it by and I have a tiny Nitecore D10 that uses a single AA and out-performs the U2 in every way (except UI). It's always in my pocket, which the U2 couldn't be for size reasons.

I have found standardising on AA to be hugely beneficial. On my last holiday I took 2 chargers instead of 5. I can move batteries between non-essential equipment, like the shaver or the camera, and put them where-ever I need them most.

The drawback of AA is that in a crisis they will be the first to disappear from stores. You can't rely on being able to buy them at will. Which for me just means I stockpile them in largish numbers.

Since one AA Eneloop will give enough light to read by for 50 hours, you don't really need that many for any reasonable disaster. For very long term disasters, rechargeable is the only way to go. Either solar power, or else siphon petrol from the cars of the people who already got wiped out by the zombies\b\b\b\b\b\bdisaster and use it to power a car charger.

My Etrex Legend mentioned a shutdown with Lithium in an old firmware version, maybe there is an update for your 60. I had already updated past that version and used eneloops since I bought it anyway.

That's very surprising! Good to know, too.

It occurs to me that with the right resistor you should be able to use those fresh lithiums. I wonder if a penny would work.



My experience has been the opposite. When a mountain pass in Colorado got hammered by a snowstorm, the only gas station around was out of every sort of battery other than AAs. They're the one kind of battery I've always been able to find in stores no matter what the circumstance. But as you say, it's foolish to rely on availability in stores. I stockpile a significant number of batteries, primarily AAs, AAAs and CR123As.



If we divide disasters into short term (less than 7 days), medium term (7-30 days) and long term (30+ days), my preparations are designed for the short and medium term. I've got more than enough batteries for that, even assuming significant usage at higher outputs. Solar isn't reliable and it's awfully slow without a significant non-portable investment. I'd rather save gas for other things.

While you've decided to handle your battery-related preparedness differently than I have, it's clear to me that you've been thoughtful and it sounds like what you're doing works well for you.