FWIW if anyone needs a charger and doesn't want to pay $150+ for a used Canon one, I purchased a $30 ebay R/C battery charger (supports nicad, nimh, lipo, etc) and it works fine charging/discharging the NP-E3. It comes with the AC brick as a separate unit or built into the charger for the same price:
The charger came with an adapter with alligator clips and there's just enough room to clip the main battery terminals to make it work (there's a polarity detector as well that shuts down the charger, in case you reverse it). You're able to set the discharge/charge rates so it is more flexible than the OEM Canon one, and in fact if you set it to the minimum 0.1a to slow discharge/charge you are theoretically doing more good to the life of the battery than with the higher rates the Canon charger does so. I guess the Canon charger is aimed more for quick charging (that's what "pro"s would want anyways) which isn't the best for the battery.
It is able to save your settings so you can just recall whatever you used last for a particular type of battery, and it also allows you to do several cycles one after the other. I'm on 3 of 3 cycles on the battery I'm cycling right now--I just told it nimh battery, do 3 cycles at 0.1a discharge, 0.1a charge, and it's all unattended so I don't have to keep hitting "refresh" to start a new cycle. I suppose you could use it for any other battery in your house if it's a supported type, so it's well worth the purchase if you ask me!
Apologies to anyone who might be trying to sell their Canon charger right now, if this post reduces the demand when people realize it's not the only charger that can do it!! lol
Some bodies, some lenses, and that's all I'll list in case the wife sees this.