Quotes from the instructions, don't have scanner otherwise would have linked it.
"Charge for 12 hours on first charge"
"Normal charging will take 1-3 hours depending on application and frequency of charge"
Green light (with no batteries on charger) - Charger recieving power
Orange light - Battery is being charged
Green light (with batteries on charger) - Batteries charged, however on first charge the green light may come on early, leave them for the 12 hour charge.
Charger was designed for US 110v ac or 12v DC car outlets, so check whether yours has a transformer prior to putting on UK 240v. (Maplins £11 if you need one).
www.code242.com may have more info.
Hope that helps.