I have had this for some time. It used to work great but the batteries need replacing now. They are easy to replace, I've done others before. Just by the battery and plug on with slip on terminals. It is charging and the monitor voltage LEDs are working good. it just needs some new cells. sold AS-IS. this is a 6V battery pack. each cell is a 2V 2.5AH   no charger included. just needs a 9VDC 500mA adapter to work