I know I'm a bit late here, but thought I'd share!
I have a datatool 3 in my Fazer, and just did something similar. I removed the battery for a few months over the winter.
Your method will work, but if you want to be careful and avoid spiking the alarm, you should do the following:
- Put the bike into service mode
- Remove the alarm fuse, then remove the bike battery
- It will continue to beep for a day or two until the alarm battery goes flat
(I stuffed bluetack into the holes in the alarm which made the beeping almost unnoticeable.)
- Replace the bike battery, then replace the alarm fuse. It should still be in service mode.
As everyone says though, you'll probably be fine with the battery in if it's just for a couple of weeks!