very sorry to read about the bike theft
i had the idea of bike tracker based on the fact that we radio track bats with UHF trackers stuck on them that last a few days and my car tracker is battery run that lasts four years - so somewhere in the middle.
My eldest had his rockhopper nicked when he was a morning paper lad. Getting his papers, locked up outside, they just cut it when he was in the shop and rode off - no one thought anything of it
we replaced his bike, now he uses an almax chain, pitlocks, kryptonite u lock and abus cable, data tracked and coded, locks weigh more than the bike