battery and frame DIY

Hello!
Is it possible or easy to attach a 36V battery to the bottle holder taking into account that the frame tube is round or circular? Will the battery and its support hold in place with just 2 screws? I doubt it a lot, but you can still convince me ...

I attached my 36v battery on my steel frame, with 3 holes. 2 were already predrilled ( not bottle holder holes) and i drilled one more fore safety reasons. No problems so far.