I have Duracell duralock rechargeable batteries with 15 min charger. These batteries run pretty good, but I keep getting error reading while charging. Sometimes, I worry these may fail anytime soon.
I never use rapid (15 min) chargers. Quick charging batteries will shorten the life (amount of charges you get) significantly. If all you use is quick chargers it can shorten the batteries overall life cycle by more than 50%. My Energizer chargers take between 4-8 hours to fully charge the batteries depending on how depleted they are, and using those chargers my batteries should be good for up to 1500 Charge cycle's.