Tripp Lite SMART2200SLT 12V 9Ah UPS Battery - This Is an AJC Brand Replacement

Someone asked me what I think about the Smart2200SLT used to provide protection and backup power for our Laboratory Instraments and associated computer system. I scratched my head, the fact is I don't think about it, ever, it just works. Installed in 2009 in central Florida where lightning results in numerous power interuptions every week, it has performed flawlessly for 4 years. It is so reliable and effective that power for our laboratory instraments is a non-issue. Annual testing shows it still provides a constant 10 amps for well over 20 min.

Specification for noise according to its PDF is < 50 dBA front side at 1 meter. Mine produces 50 dBA when its always-on 80mm fan is running at its minimum speed. The fan runs on high speed roughly 1/3 the time, low speed roughly 1/2 the time, and medium speed the rest. It determines what speed to run, on no particular basis I've been able to discern. Noise level here 1 meter from front is ~50 dBA on medium, and ~55 dBA on high, which is nearly triple the claimed noise level (3 dBA is a doubling of volume). On high it drowns out every other sound in this building unless I turn the stereo on quite loud or run the vacuum cleaner, laser printer or electric drill. This should have had either a 120mm fan that provides enough air at a considerably lower noise level, or a revised design that does not produce so much heat as to require so much airflow. Heat from fan's output is too low to be detectable to a hand placed adjacent. This UPS is clearly too loud for a home or professional office. It's like having a printer running non-stop.