theres a review on there
"I have owned one of these chargers for 5 years and have found it to be the best.
It will charge all sizes and types of 12 volt batteries. There are two selector switches, one chooses Lead acid or Gel, the other is for Car or Motorcycle.
When connected to a part charged battery, the lower LED lights whilst charging at about 8 amps. Once it is charged, the top LED lights and a low amperage pulse charge, varying between 1 and 3 amps, is applied to maintain the battery at peak level.
This is a fully automatic charger. Connect it to the battery and wait for the upper LED to light.
Simple and very effective."