I have a Northwestern Bell 36007 cordless phone. The battery conks out
much sooner than it used to, so I assume it's time to purchase a
replacement battery. The problem is the three stores I have been to so
far apparently don't recognize this model (at least in the compatibility
directories)!

For what it's worth, it uses an NICD 3.6 V rechargeable battery, 450
mAh. As far as type/size/plug, I have found similar batteries in these
stores, but none with the same milliAmperehour value (450).

Does this matter? Isn't this value merely how long the battery will keep
a charge? Is it safe to go with a 3.6 NICD battery that is 1,000 mAh?

TIA.