Amount of Energy in Elemental Masks

You’ve said before that elemental masks have some amount elemental energy, but that they can’t regenerate their power while Toa can (Official Greg Dialogue | Page 105) How much elemental energy (as in fuel before it loses its power) do these masks have compared to Toa? Toa elemental power doesn’t seem to last very long before needing to recharge, so do the masks have more energy than a Toa, or about the same?

If about the same (or even less), and assuming a Toa wears an elemental mask of their own element (example: a Toa of Fire wearing a mask of Fire), does the mask act more like an emergency reserve for when they have lost access to their normal amount of energy?