A note of caution. The power output from a UPS while running on battery is not a pure sine wave like line AC. Its an approximate sine wave consisting of a coll

A note of caution. The power output from a UPS while running on battery is not a pure sine wave like line AC. Its an approximate sine wave consisting of a collection of square waves. This output is generally very noisy (i.e. has a lot of high frequency elements). The output is "close enough" to a sine wave for most electronics to run but the high frequency noise is damaging to the input circuits because they generate a lot of heat. This problem is worse on the low-end UPS's because one way to cut the costs is to save money on the DC-to-AC converter and accept more noise on the output line when running on battery. The higher-end UPS's (particularly models that are designed to run long term) have higher quality DC-to-AC converters which is why they are more expensive, not due to just larger batteries. One final note, this project seems like a really uneconomical use of time and money.