Inverter saved the day

[BC Mosaic]

Well the power went out in my neighborhood very early this morning. Luckily, I am the sort that thinks along the lines of, "What if this or that thing should happen?" and then implement a fail-safe remedy (hopefully). With my set up the tank could not handle a power outage or else there'd be an overflow happening onto the floor plus all the critters would suffer. So when I first set up the system I got myself a deep cycle battery from Canada Tire (about $150.00) and a used inverter from a member here (cheap on eBay as well) and hooked it up to my return pump. This way, should there be a power outage, there will always be water circulating and everything should survive until the battery is drained of course. This should take awhile because I only have the one pump connected to it - the most important element in the system.
The reason I knew there was a power outage was because when the inverter kicked in the battery/inverter (?) whined a high pitch sound that woke me up (I sleep with my tank ). Is it normal for it to do this?
I think that this was a very good investment on my part and if no one minds, I'm giving myself a pat on the back. LOL
Just thought I'd share.