I have said it before on this list, and I will say it again..... Charging batteries in the scanner is asking for the kiss of death.
At some point, one of the batteries will fail, and heat up enought to melt or warp the board in the scanner, which according to all of the variations of Murphy's Laws, will be out of warranty by about a month. I lost a BC250D that way. The repair cost was not terrible but it was enough to teach me that lesson.
I have purchased a LaCrosse charger from Thomas Distributing, and several sets of NIMH 2600 MAh batteries. I am very satisfied with their customer service (almost as good as Uniden...thanks Paul).
http://www.thomas-distributing.com
They carry all types of chargers, so just find one that has the features everybody suggests and the right price for your budget. Look for one that charges each cell individually. Mine lets you select several options, like regular charge (10-14 hours), a discharge-charge cycle that prevents or eliminates any memory effect and continues until peak charge is acheived (24 or more hours), etc. You can actually select a different option for each cell. For NIMH, a slower charge is better than a 1 hour quick charge, so I have several sets, which keeps one in the charger one in the radio and one in my pocket. ( and a couple extra, too).
I usually get 8-10+ hours of almost continuous use from the 2600 MAh batteries and they have some really good prices/deals, like a free plastic case to carry 4 extra batteries in.
I have also seen packages of charger & batteries in Sam's and COSTCO, so I guess Wal-Mart and Best Buy could also have them at slightly higher prices.
Good Luck.