Sony Quick Battery Charger with 4 AA Ni-MH Rechargeable Batteries

It doesn't say so in the product description page here anywhere (and I can't even find this charger on the Sony website), so here you go: it takes about 4.5 hours to fully charge the four 2300mAh batteries that come with the charger. Which I kinda like--I like that it's not a dumb charger (timed charger w/o regard for existing charge or overcharge) like the cheaper Sony charger here on Amazon.com (BCG-34HLD4), nor does it take inordinately long (some others I checked out take as long as 8-12 hours), but it's not a superfast 1-hour charger that super-heats up the batteries during the charge (and potentially reduce the battery service life).
The charger has the outlet plugs built-in, so there is no separate AC adapter. Be sure to keep the charger bay door open during charging to help dissipate the heat.
The batteries are Sanyo-brand ("HR" imprint on them) marketed under the Sony label.