I decided to restore an old Bearcat 200 XLT scanner, and rebuilt the batter pack with 1800mAh NiMH cells, Using the stock Uniden charger, how long do you think it shoud take to charge it? The manual states 12-14 hours for the 600mAh NiCd pack which seems high. Do I really need to charge this thing for a day and 1/2?