What would be better for an atomic battery?

I'm experimenting with atomic batteries and and I'm trying to find the best form of energy. I'm debating on using beta particles and betavoltaic cells or alpha particles and alphavoltaic cells. According to the website listed in my sources, it says beta particles release energies varying from 0-3 MeV (Megaelectronvolt) while alpha particles release 2-10 MeV. Also, there is a far wider range of beta particles emitting elements. Please help me choose if you have any knowledge on the subject. Thanks in advance!