Canon EOS 30 - Battery pack.

I have just acquired a Canon EOS 30 slr. The battery pack for that model is the BP 300. However, here in the UK I saw an advert for the BP 300, and the well known dealer stated that it is also suitable for the Canon EOS 50E/50 models. When those cameras were released their battery pack was the BP 50.
Does anyone know if the BP 50 (for the EOS 50E) IS COMPATIBLE with the Canon EOS 30 ?
Thanks in anticipation, it might save me a bit money.