I noticed that many sites sell replacements for the BP-2L18 battery and claim it is compatible with the HV20. They rate it between 1800 and 2000mAh which is a serious improvement vs BP-2L14.
The problem is that I can't find that battery in the compatibility list and I can't even find traces of any genuine Canon BP-2L18. This reference just doesn't seem to exist (anymore?)...
Does anybody have more information about this reference and can someone confirm it actually works on the HV20 ?