This 28v 1.4 AMP Intelligent High Frequency Charger is only suitable for MOTOCADDY 28V M LITHIUM golf trolley batteries fitted with GREY & BLACK battery connectors. Stage “Ip” is a pre-charge function for deep discharged battery packs - This is helpful for battery cycle life! When the battery is recovered by the small current pre-charge, stage “Im” will give bulk current charging (up to 50W). Then, “Um” stage is followed, the output voltage is limited on C.V. point until the charge current has fallen to 0.1 C.C. value. We are aware of cheaper units on the market but this is a quality product developed specifically for the use with lithium golf batteries - You will NOT be disappointed with the results! the store no longer allow us to link to our help pages or offer a phone number, so please refe.