A few days ago I got a Yoobao 2400MAH battery on ebay for $25 shipped. Here's my little review so far after a few days of use.
Background: I'm an avid RC flyer. I own electric powered and gas powered planes and have done a lot of work with Lipo and Li-ion batteries and have applied the same things I've learned from there to any and all batteries.
Few things I've learned is never let a battery drain to it's bare minimum. I've read numerous times that one should let the battery die all the way and charge it all the way and let it die again. For Lipo and Li-On, 80-90% drain is ideal before recharging again. I'll continue with this later. This does not apply to the G1 though, just a general pointer. Read post 11 to see why this does not apply to G1.
Now on to the battery.
The battery comes with the the extended cover. Which has a nice rubbery feel to it.
The battery came with the charge at 70%, which is nominal for shipping and storage. i got it and plugged it in and charged to to max. I then used it through out the day and right off the bat, it was performing wonderfully. By the end of the day, I still had 60% power left, when normally, I would have drained the stock battery by now. I did not charge the battery that night (Monday night) and by morning still have 50% charge. I charged it when it was down to about 15%, a full charge took about 2.2 hours. Which sounds about right, assuming the wall charger was providing 1Amp constant, the 2.2 hours of charge time equates to about 2200Mah of charge.
From a full charge, I've watched a 2 hour long movie, gtalked, SMSed and it has drained about 40% (60% remaining).
It is typically offering twice the length then my stock battery was, Though I've had it 3 days, I will continually update this thread.
i do have the tools and equipment to measure the charge this batter takes in So I will do that tonight and report my findings. I plan to drain the battery to 15% and charge with my digital charger and see how many MAH it takes in. I expect it to take in minimum 2000mah at 85% discharge.
So far, I give it a thumbs up especially at $25.
My brother has the seido 2600. I will test that as well.
Conditioning the Li-on battery by draining it to 0% and recharging and then draining to 0% is rather harmful to the battery. Lipo and Li-on cells do like going below 3.0-3.2V. The Nominal Voltage of the cell is 3.7V, a fully charged cell is at 4.2V-4.25V or so. Dropping it below 3.0V cause more harm to the battery then good. (Again this does not apply to G1)
Try to avoid draining the battery all the way if you are not able to charge it. Most phones have a cut off point, and my guess is for the G1 battery, it's 3.2V, or I hope it is (actually, it's 3.5V as you will read about it in post 11). But you use the phone to where it cuts of, and are not able to charge the batter for a few days, then that could drop the voltage to below 3.0 (over time). I've seen people do this when they use multiple batteries, and end up killing all of them because they let them sit while fully discharged. Big no no with Li-ons.
LI-on doesn't suffer from memory loss , charge them whenever possible. They do how ever become uncalibrated. Meaning if you constantly plug it in at random discharges (which is perfectly fine), the state of charge may differ from the actual charge gauge. Simple problem to resolve, Drain the battery too 3.2V ( I will post if draining the battery on the g1 to 0% is 3.2V or not) and fully recharge.
More numbers on the Yoobao, Seido and stock batter later.