For years I have been using an old Uniross charger with Maplin aa/aaa rechargeable batteries, however the kids keep complaining that they don't last long and when I tested them they didn't appear to be well charged. Anyway whilst on the net to find the best rechargeable batteries ( Panasonic Eneloop) I also ended up looking for a replacement charger, most of the reviews were from USA but I came across the UK equivalent and purchased from Battery Logic the above, which also came with 10 x Eneloop 3 aa batteries. It cost £50 and arrived in 2 days so good customer service.
This is an intelligent charger which will charge up to 4 batteries of different sizes at the same time. You can select charging voltages and alike for each individual battery. It has a very useful charge /discharge function which allows you to refresh old rechargeable batteries.
It comes with detailed instructions and was easy to set up. Needless to say its now been running for 2.5 weeks and I have now restored 20+ batteries to their peak performance. Some took several days on the refresh cycle to get back to full capacity. Also the charger will identify defective batteries.
It is an excellent bit of kit and is a must buy if you use AA/AAA rechargeable batteries.