I have the Psycosomething another, I'm trying to think of the name of the brand, the logo is a thumbprint with a swirl in the middle, only place you could find this brand is at Target around here at least.
the battery packs last for about 20-30 hours at a time and take an hour or so to charge, I DON'T put them back in the charger non-stop because that'll ruin NiCAD batteries pretty quick (cause they'll always trickle charge) but unlike some of the other recharge packs you can see the batteries start to fade in power and you'll have ample time to charge them before they die on you while playing
Also I liked their base station and packs the best and they were the cheapest out there as well, charger base and two packs for 20$ I think, and I've had much better luck compared to the Nyco brand. You can pick up another two packs for 10$ I think.
They also make the best battery powered IR Sensor Bar as well, has a 15-20 hour time, can charge off anything with a USB port. And it's not Ginormous
I grabbed a couple of cheap replacement battery compartments that charge over USB from eBay over a year ago and have never had any problems.
They're only 1800mAh (although you can get much bigger) so the charge only lasts for about 4 hours but that's normally enough for me. Basically you plug the usb cable in the back of the Wiimote and BINGO! Works a treat via either the PC or Wii although I tend to recharge using the PC just in case charging via the Wii on standby causes problems. I'd recommend these over a charging station cos they still work fine with covers on the remotes (I just made a small hole in the cover for the cable) If you have a cover on the remote they tend not to fit in those Nyko-style docking stations
I bought an internal Wiimote battery system from Gamestation in UK, it has a battery block that fits in the remote and a replacement battery cover that has two contact plates on it that touch the batteries and on the outside there are also two plates, this then just slots into a wiimote charge station plugged into the USB port, charging is really quick.