I purchased this item new in June 2000, and it has been unopened since. I have no plans to use it, so I am offering it for sale. Product Description The MPPT Charge Controller 60A ROVER LI series is a negative-grounded controller applicable to various off-grid solar applications. [Maximum Charging Current, Input Voltage, Input Power] The maximum charging current is 60A, the maximum input voltage is 150VDC, and the maximum input power is 800W for a 12V system, 1600W for a 24V system, 2400W for a 36V system, and 3200W for a 48V system. [Automatic Recognition of 12V/24V/36V/48V Systems] It automatically recognizes system voltages of 12V/24V/36V/48V and is applicable to various batteries, including gel and lithium batteries. [High Tracking Efficiency and Protection Functions] It boasts a high tracking efficiency of 99% with innovative MPPT technology. This maximizes the characteristics of solar panels and reduces power generation loss, allowing for the generation of more power without waste. It also has comprehensive self-diagnostic functions and protection functions to prevent overcharging, over-discharging, overload, and short circuits. [With LED LCD Screen] [With Load Connection Terminals] [Remote Monitoring & Operation Using BLUETOOTH] Main Features ・Automatically recognizes DC system voltages of 12V/24V/36V/48V. ・Applicable to deep cycle sealed, gel, flooded, and lithium batteries. ・Innovative MPPT technology achieves a tracking efficiency of 99% and a conversion efficiency of 98%. ・Prevents overcharging, over-discharging, overload, short circuits, etc. ・The LCD screen and LED indicators display system charging information and error codes, and allow for parameter changes. ・Equipped with various load controls. It can also charge over-discharged lithium batteries. ・Includes an RS232 port that can be connected to the Renogy BT-1 Bluetooth module. Important Notes ・The temperature displayed on the LCD screen is the internal temperature of the charge controller. When connecting a temperature sensor, the battery temperature can only be checked within the app. ・An inverter cannot be connected to the load connection terminals. If you are using an inverter, connect it directly to the battery terminals instead of the load connection terminals.