The more I read about torches etc on here the more I realize I don't understand. 

Not only are there different battery sizes, there are various types, NiHM & Li-on etc,  different capacities, protection, regulated un-regulated and the odd disclaimer about blowing yourself up etc.  My Mrs would be very upset if I blew myself and the garage up as she'd have to redecorate it herself.

For those "in the know" which batteries (Sizes AA, C, 18650) would you select and why?

e.g. SAMSUNG L18650 appears to have a high capacity  - any good?  http://www2.produktinfo.conrad.com/datenblaetter/250000-274999/251024-da-01-en-LI-ION_Akku_Samsung_L18650.pdf

Are Li-on & protected best?

Any other tips on how not to blow myself up while charging / discharging battereis would be appreciated. 

theiving git.

anyway yes look at that website.

OK you have the storage medium, capacity and voltage.

if you have a 12 volt bulb you need a 12 ( or near enough) battery, or batteries, ie four 3 volts in series = 12 volts. then you have the capacity, if your bulb uses 500 m Amps and hour then a 2 Amp Hour battery will last you 4 hours.

just make sure you use the correct chager and lithium polymer should be protected to stop them going wrong.

18650's is my choice and what I'm moving over to completely at the moment,  @50gram weight,  3.7volts,  2500ma so same as 3xAA's and less hassle as only 1 and lighter to carry and only got to charge 1 instead of 3

I run protected ones,  over  discharging CR123a's has killed alot of them over the last year.

just order :-

2 of these for your helmet!!

1 x P7 for your bars

This Charger get 2 if you want to ride frequently

4 packs so 8 Cells it'll give you a all on run time @5hours!!

Mount for the P7

Spread it over 2 or 3 orders Free postage to avoid customs charges

EASY!!!!

Sadly,  been REALLY slow delivering recently

http://www.oknewshop.com/

UK / Europe Shop there seems alittle bit more,  see if you can find some of there stuff there for faster delivery!!

Yes was thinking of going for 18650's providing the torch(es) I choose can accept them.

I see it's not just a lumens story, the spread of light is also important (see pics in link).  Is the P7 more a spot or flood light?  can see too much spot light in the middle could be a problem. 

 http://www.messerforum.net/showthread.php?t=41827

 On some german bike forums the "FENIX L2D" is often favoured as the light distribution is much more even.   

 Some more beamshot pics of various lights here ....

http://www.ledmania.cz/fotky-venku

 Various light reviews here

http://light-reviews.com/reviews.html

DB,  the P7's makes a good Flood,  fairly uniformed brightness throughout the entire viewing area and it fades from the spot to the spill very gradually,   unlike my other torches where it's a very well defined spot,  hence great on the bars.

There are very very few Torches which work with a 18650's,  that torch linked above has quite a wide spot area,  but it's the only 1 that works with 18650's I can find,  I'm using a drop in alone same price as that torch on it's own,  but a tighter spot and longer range.

L2D and the Torch I linked,  both have the same CREE Q5 LED!!

Trust me I've been playing around with various torches for the last year, the P7 bar mounted out does HID's for a fraction of the price,  with 2 of those torches giving a look around when required.