This may not be the cheapest charger, but it has a discharge function which is essential to prolong the life of NI-Cd or NI-Mh batteries. The product has pretty good reviews too.
The spec is pasted below.
The superb V8 Super Charger is capable of charging up to 8 x AA (or AAA) Ni-Mh batteries at a time. Perfect for busy people who like to save lots of money. You will not find better value anywhere in the UK today for a product with similar specifications !
The BRAND NEW 7dayshop V8 Super Charger is a top quality microprocessor controlled charger, capable of charging up to eight AA and AAA size Ni-Mh (Nickel Metal Hydride) rechargeable batteries. In use it is extra convenient and hassle free as all of your batteries are charged in their own individual and fully monitored channels. Mixing and matching at any time is no problem and naturally because eight batteries can be charged in one go it saves you time in having to remember to change the batteries over etc.
The terrific price includes a Universal Voltage Mains Adapter which makes it suitable for World-wide use (of course an adapter may also be required to fit into 2 pin Euro/USA sockets for example).
The V8 Super Charger is also supplied with a FREE 12V car lead (uses the cars cigar lighter / 12V power socket) for the ultimate in charging convenience and is also supplied with full (and easy) operating instructions...
Recharges from 1 to 8 x AA or AAA batteries at a time
Super safe microprocessor control, fitted with “Delta-V” overload detection, thermal and timer protection and also reverse polarity protection too
Smart design also incorporates a special discharger/battery saver function (blue button) for reconditioning your Ni-Mh batteries!
Automatically switches charging between AA and AAA size batteries
Green/Red LED lights indicates rapid/trickle/full charge and also warn of bad cell detection or where batteries have been inserted upside down etc.
Smart design, silver colour top plate with grey base. Unit measures H11 x W20.5 x D3cm
This unit may be used with all good quality Ni-Mh rechargeable batteries.