Li-ion Battery Charger parameters: Input:AC 100-240V 50/60Hz Output:54.6v 4a (max) Output connector diameter: DC 1 prong 5.5*2.1/2.5mm Connector electrode polarity: internal + external - (please make sure the output electrode of the original charger is the same as this charger) Suitable for battery parameters: 48v lithium-ion battery packs Charging mode: CC-CV Attention: 1. After getting the charger, please access the AC power supply, see whether the LED indicator on the charger panel is bright green (bright green indicates that the charger is intact), access to the battery after the charger to red charging state, the battery is almost full of time there will be indicator light flashing, a slight flicker is normal, when it turns into a green light, you can keep continue to charge for half an hour until full (because the charger will turn to a green light to continue to charge the battery with a very small current, this is the first time that the charger will continue to charge the battery with a very small current. (because after the green light, the charger will continue to charge the battery with a small current, which is to better protect the battery) Special Tips: 2. If the charger can't charge normally, you can try to unplug the interface again, the charger will work better if the contact is good. If the battery interface has been used for a long time, there is wear and tear, can also cause the charger and the interface contact is poor and caused by the situation of not charging, there are any problems can be the first time to leave a message to the staff of YZPOWER charger! 3. Please unplug the AC charger in time after it is full. 4. Don't use it in humid environment. 5. Please do not cover the charger when it is working.