U-series uninterruptible power supply controller with quick-connect spring-clamp terminals. It is compact and easy to install. Longest buffer time in class. Easy battery access. Stable output voltage in buffer mode. Superior battery management for longest battery life. Temperature compensated battery charging. Comprehensive diagnostics and monitoring functions. Replace battery signal included. Electronically overload and short circuit protected. 50% power reserves. Selectable buffer time limiter. Suitable for 3.9 and 40 Ah between battery sizes.