Beginners Guide to riding Fixed/Single Speed in London

I don't get it. They will discharge what the thing they are plugged into draws.
The higher the demands of the light, the quicker the battery will go flat.

I don't know anything about 'hybrid' batteries, never heard of them, but the link you posted seems to refer to a standard NiMH battery. Where's the explanation of this 'hybrid' stuff? I'm curious since my current set of NiMH batts I use with the Dinotte are coming to the end of their lives - some need charging after an hour, for example.

The point is: They Discharge when not in use. They slowly lose the charge, which might be important for lights because they are not in constant use.

An article explains it all here:

http://www.metaefficient.com/rechargeable-batteries/best-rechargeable-batteries-and-chargers-for-2007.html

The other key thing is that these kind of batteries don't just eventually die like the ones you have been using. They only die due to improper charging, which most cheap ones do.

A bit about the charging, and the charger in particular, is here:

http://www.steves-digicams.com/2002_reviews/maha_c401fs.html

A little bit of the technology from the Ansman site here:

http://www.ansmann.de/cms/en/consumroot/batteries/rechargeable-batteries-nimh/rechargeable-battery-maxe.html

As the graph shows, the question is how long do batterys last as lights? If it is only a few weeks, then the slow discharging where it 'seeps out' is not a problem. Therefore you can go for regular rechargables. However, even if you do this, you should still get good batteries and a charger since the will effectively last forever. Examples of these are the Mignon's shown also on the Ansmann site, which go up to 28500ma.