Hi - Thanks for that, yes you're correct the UPS will last up to around 2hours. We thought the best approach would be to take SQL down cleanly, only if the UPS kicks in as we're unable to get a definitive answer that the work will definitely have an impact.
I will of course check the backups prior to doing anything. I believe when we've had a power down before we've checked any sql jobs and have then taken the Server down and powered up when safe to do so.
Does this sound like a plan?