Just bought a Sony HC53E Camcorder. Very annoyingly my old, identical looking, same 7.2v, Sony NP-FP Camcorder batteries from my previous defunct model [Sony HC22E] don't fit this new HC53E camcorder though, thanks to a few mm more plastic on the base lugs and Sony's new [anti-copying] info-lithium chip. Trim the old NP-FPs to fit in the HC-53Es NP-FH slot and the camera says 'incompatible battery' - i.e. it's got an old style info-chip, even though it is a Sony battery of the right shape, voltage and power. So I had to buy one of these `genuine' Sony NP-FH50 as a spare battery [it's the same physical size as the NP-FH30 supplied with the camera, but with a tad more power reserve].
Sony have nobbled the new HC-53E camcorder so that cheaper generic ones can't work without a naff patch cable and thus can't provide the very useful 'time and % battery charge left' graphical info on-screen. This anti-piracy mod isn't to stop others manufacturing batteries and passing them as off as counterfeit Sony's [the 'generic' were always branded], it's simply trying to force you to buy the rather overpriced Sony batteries that can cost over half the price of the entire camcorder. That said I got this Sony NP-FH50 for around £30 from Amazon resellers, which wasn't bad value [although my complete Sony Camcorder + NP-FH30 battery was only £120 from Amazon].
You can recharge these Sony NP-FH50 batteries in the camera, but I bought a £15 generic mains/12v car charger combo, so that I can recharge one battery while filming with another.