[Touch Pro2, Tilt 2 Accessories] d0ugie:
We all want better battery life, no question, more than processor speed (some of us even underclock), resolution, 3D drivers; pretty much everything takes second place in our hearts to battery life. In response to that demand there are a lot of companies out there selling batteries for our phones either at the same mAh rating of the OEM (the one that came with the phone), a higher mAh rating but the battery's the same dimensions as the OEM and does not require a deeper cover and batteries that are both larger in capacity and physical size -- or so they allege. Usually these batteries are cheaper than the OEM's, mAh for mAh at least. By the way, mAh ratings, or milliamp hours, think of it in terms of the size of a gas tank you installed in your car. The higher the figure, the longer you can use your phone.

Got a Nexus One? Say hello to our sister thread! No wait, just go straight to forum.batteryboss.org right now, forget this thread.

There are battery threads all over XDA but only with vague data so I invested in equipment to rate the batteries myself, under the guidance of electrogeniuses as you can read in this thread, in order to tell you what to expect in addition to giving you figures such as how many amp hours you get on the dollar as maybe a cheap battery with an exaggerated or oddly defined rating is worth getting over an expensive and better one if you're on a budget. Not counting all the man hours that Telek, amit77 and I have put into coming up with the most reliable way to produce data, so far I've spent over $200 on different equipment to get to where we are now. By the way, OEM = made by the people who made the battery that came with your phone. I'm not asking you to donate yet or reimburse me for my troubles, rather I'd like you, the next time you buy a battery I haven't already tested, to mail it to me first so I can run a couple tests after which I will FedEx it to you at my expense. If that interests you, PM me. If you are a battery manufacturer or reseller and you stand by your claims and trust me to run legitimate tests on it that are consistent with every other test I publish in terms of procedure, PM me or post publicly.

The procedure:

I am using the Computerized Battery Analyzer III. The software which is somewhat sophisticated plots out milliamp hours (mAh) burnt over the descent of voltage from 4.14V to 3.5V which we have determined to be the level of voltage in the battery at which point the phone decides to stop charging itself and decides it's time to turn itself off because it's too low on juice. The CBA software plots out data in graphs, PDFs, CSVs, the whole deal. Looks a little like this:

In order to produce the best real-world information, numbers that are relevant to you and not just to academics, I charge the batteries with the phone as you do until the phone decides the battery is charged which for the Rhodium/Touch Pro2/Tilt 2 is 4.14 volts regardless of capacity rating. I hook the batteries up to the CBA which is plugged into my computer. With the software that came with the CBA I have the CBA test the batteries at 250mA, a current in the neighborhood of what the average user would average were he to do his thing (including having push-mail fired up with the screen on bright, downloading and browsing rss feeds, the occasional call, bubblebreaker etc) without interruption. To get a better idea of what kind of current you're using when doing various things use the attached acbPowerMeter software. I'm not Geraldo Rivera out to get the third party guys that exaggerate their numbers a little bit nor am I here to rewrite Wikipedia's take on capacity calculation industry standards. If you're a manufacturer or a battery company sympathizer and want to break my balls about voltage cutoffs, read this simple explanation which I feel sums up our position well. The point, in short, of all of this is to supply you with information that will help you choose which battery to buy.

Doug Simmons