Can a headlight battery be reconditioned if it won't hold a charge? I have an older CygoLite headlight that I used for commuting for a couple years.  It's been in storage for about 12 months, and now it seems like the battery won't take a charge.  I think its a variation of a NiCad battery, not lithium. The battery looks like this:



Is there a way to recondition a battery or do I just need to replace it?

Note - I have plugged the light assembly into another similar battery and it works, so I know it's not the bulbs.
The battery is probably shot but the battery pack can be rebuilt.  An outfit like "Batteries Plus" (in the US) can do it.  Or you can generally do it yourself if you're fairly clever (though getting it professionally rebuilt is better because they have the right spot welder, etc).

(It would be nice if the light mfgrs would use standard tool batteries rather than their own designs.  It would be fairly easy to build an adapter to hold one in a water bottle cage, eg, and then replacements would be readily available and you could use the tool charger.)