Recharge Light

       Usage: cast 'recharge light' <target> : cast 114 <target>
      Effect: Increase light's burn time
        Cost: 200
    Duration: Instant
Casting Time: 24
      Target: One light

This spell will add time onto the lifespan of a light.  There is a chance,
10-20 percent depending on caster level, that the light will be destroyed
each time this spell is cast.  This will also happen if you charge the
light with more than 24 hours of time, so be prudent with use of this spell.

The classes that get the spell recharge light are:

cleric     : Level  46 (fair)
priest     : Level  24 (excellent)
wizard     : Level  27 (average)
druid      : Level  35 (excellent)