So why am I interested in battery chargers? Partly for environmental reasons (we throw away too many batteries), partly for efficiency (we don't make good use of our batteries). I think rechargeable batteries are a great case study on making more efficient and environmentally-friendly use of our resources.
What do I want from a battery charger? Much of what the top-end battery chargers do: separate channel charging; smart charging cycle management; refresh/reconditioning; battery capacity testing; etc. This is all useful getting best use out of batteries, and in lengthening the mean time before replacement.
But what battery chargers don't seem to do, however, is collect data. Charging data (voltage/time) and battery capacity testing data can easily be collected by a charger and communicated to computers via wifi (or Bluetooth). This information could be transmitted back to manufacturers (via the Internet) to aid in their battery or charger development, and to give them real-world use data. To get really granular data, each battery could be printed with a unique barcode or QR code. This would allow sensors in the charger to collect per-battery data, transmitted to users, and back to manufacturers. (Consumers could be provided with stick-on bar codes to label up existing batteries.)