Lithium Batteries

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#1 Post by **round_ourway** » Thu Nov 08, 2007 3:34 pm

I don't know if they exist - but I'm lookin rechargeable AA lithium batteries for the headlamp. cheers in advance

#2 Post by **thescotsman** » Thu Nov 08, 2007 4:46 pm

You can get rechargeable lithium batteries ok, but not AA size as such. As far as I know the cell voltage is 3 - 3.7 v so if you had one AA sized it would still be over 3v. (NIMH are 1.2v, alkaline 1.5v)

There are cells which are the size of two AA batteries so would have a volatge similar to two 1.5v aa batteries (some cameras use them for instance), so you might be able to rerig the headlamp to use that (NB, I am not advising you to do this though!!)

There are headlamps coming out with lithium cells in them already, so maybe you can get one of them and get a rechargable one for it. It is very important that you use the correct charger for the battery though.

#3 Post by **round_ourway** » Thu Nov 08, 2007 4:59 pm

good man cheers, will check it out

#4 Post by **thescotsman** » Thu Nov 08, 2007 5:07 pm

no problem. Off the top of my head radionics have rechargeable lithium, some of the other electronics places have camera specific batteries and no doubt they are available on ebay and from the states......
Strangely enough, I was thinking of the same thing a while back, which is why I know....never did anything about it though....

#5 Post by **round_ourway** » Thu Nov 08, 2007 5:12 pm

I was surprised how little the ordinary rechargeable batteries lasted tbh. a set of lithium batteries would be sweet for the headlamp but they are pricey enough without ripping them apart to put into the headlamp.

#6 Post by **thescotsman** » Thu Nov 08, 2007 6:43 pm

actually you can get a 1.5v lithium battery it would appear - see link
[url]http://www.energizer.com/products/lithium/[/url]

As for 'normal' rechargable - depends on types and I think even manufacturer, and what kind of bulb is in your torch.

In theory I think a rechargable NiMH should last as long as an alkaline battery (at least the newer 2700mAH should) - think they have comparable mAH times, but lower voltages. I agree that they don't seem to last as long, but that might be the batteries I use? I usually get a session (maybe two) out of mine with 4 2700mAH AA batteries and a 'normal' incandescent bulb. Certainly got longer when I had some duracell (not an endorsement btw). A 3v 0.2A bulb you'd expect 13 hours or so from with two of those batteries I guess. Just estimating here so if someone knows better, please correct me.

I get about the same amount of time with 3 AAA 700mAH in my single led head torch as the above torch, although I find it dims a little bit after an hour or so of use, but keeps going at that for a while.
I usually find myself charging them after every trip now, just to make sure they will last the whole of the next trip.

#7 Post by **thescotsman** » Thu Nov 08, 2007 6:51 pm

like the environmental claims from the energizer site :lol:

Is lithium safe for the environment?

Yes. Much of the concern with the environment centers on heavy metals.
Lithium is the lightest metal known.

#8 Post by **roger de dodger** » Thu Nov 08, 2007 7:16 pm

if you use rechargable batteries in three,s check your charger as alot will only charge 2 or 4 at a time so if you put three in one wont get charged ,this will lose you hours of light , so read the instructions on the charger :oops:

#9 Post by **round_ourway** » Fri Nov 09, 2007 8:52 pm

Thanks for that fella's, sounds like what im looking for. I have the Princeton headlamp and the same batties as yourself scotsman last for at most two sessions thats with the lamp on most of the night. thanks again lads I will try out those new lithiums ones see how they get on.

#10 Post by **roger de dodger** » Sat Nov 10, 2007 5:31 pm

argos are doing ultimate batteries for 5.99 a pack buy one get one free lithium but not rechargeable but good value compared to duracell