i also use 10Ah NiMH D cells on my bot.
i haven't been able to find a particularly good charging solution as yet.
the charger i'm currently using is similar to the first link Vidam posted.
it's not ideal because after a charge it drops to a trickle charge of 100mA which is pretty pointless on a 10Ah pack. (the one in Vidams link trickle charges at 250mA which is a little better but still less than ideal.)
i think i'll have to give up and build one which kind of sucks because i'd rather be building the robot.
my ideal charger would sense battery voltage and quick charge the pack @3A up to about 13.5V then drop to about 700mA and trickle charge at that level indefinitely.
that way i could have the bot drive into it's charging station and start charging without human intervention.
dunk.