Tests of batteries being sold for HTC's Nexus One, Incredible, EVO 4G, Hero, Desire and Touch Pro2/Tilt 2. Thorough explanation on MobileCrunch. Fire up forum.batteryboss.org.
Updated August 7th (today's May 24th).

Battery description

Rated at

Tested at

Rated v tested

$ per amp hour

 Cost+US S&H+tax

Remarks

 Made possible by
Nexus One, OEM 1400mAh 1357mAh png/csv 97% $18.42 $25, link N1's OEM setting the bar high MobilityDigest
N1, Seidio 3200mAh 2691mAh png/csv 84% $28.19 $75.85, link Well at least Seidio beat Mugen Roto
N1, Seidio 1600mAh 1305mAh png/csv 82% $38.29 $49.97, link Seido's apparent playbook Roto
N1, Cameron Sino oversized 2400mAh 2029mAh png/csv 85% $10.79 $21.90, link Not a bad deal, includes door Roto
TP2 OEM standard issue 1500mAh 1414mAh png/csv 94% $10.60 $14.99, link Seller may no longer be legit Sean Graham

TP2 OEM, mini

1100mAh

1054mAh png/csv

96%

$7.57

$7.98, link

 OEM rated right AT&T warranty
TP2 Mugen 1800mAh 1414mAh png/csv 79% $24.01 $33.95, link Mugen is disputing our methods Jeremy Riley
TP2 Mugen, exchanged 1800mAh 1256mAh png/csv 70% $27.03 $33.95, link Seriously Mugen? Mugen, Jeremy
TP2 Seidio, light use 2 mos 1750mAh 1383mAh png/csv 79% ≤$28.56 $39.50, link Not new but still disappointing Jason Weaver
TP2 No name #1 1500mAh 1237mAh png/csv 82% $5.58 $6.90, link Package deal, two batts Doug Simmons
TP2 No name #2, large 3600mAh 2466mAh png/csv 69% $8.02 $19.85, link Nowhere near claim, bad door MobilityDigest
TP2 Fake OEM #1 1500mAh 1210mAh png/csv 81% $5.17 $6.26, link Counterfeit, seller removed item MobilityDigest
TP2 Fake OEM #2 1500mAh 826mAh  png/csv 55% $7.15 $5.85, link Bad counterfeit, seller refunded Doug Simmons
TP2 Fake OEM #3 1500mAh 1248mAh png/csv 83% $5.01 $5.85, link eBay seller ibestone still faking Shawn Martell

TP2 OEM, used 6 months

1500mAh

1307mAh png/csv

87%

≤$11.47

$14.99, link

 Not bad for 6mos use MobilityDigest

TP2 Andida, light use 4mos

2000mAh

1198mAh gif/csv

60%

≤$8.34

$9.99, link

BS mAh but good cheapo

 MobilityDigest
TP2 Andida, new 2000mAh

1101mAh png/csv

55%

$9.07

 $9.99, link Yikes, worse than the used one Shawn Martell
TP2 OEM, new 2150mAh 2150mAh png/csv 100% $18.36 $39.47 TP2/AT&T Jackpot! Boldface appropriate! Wade Woosley
Hero, no name, oversized 3200mAh

1790mAh png/csv

56%

$6.14

 $10.99, link Weak but cheap Dan Mason
Hero, Mugen, oversized 3200mAh

2396mAh png/csv

75%

$33.37

 $79.95, link Wow Mugen, $80 for this? Jason Triplett
Incredible OEM used 1m 1300mAh

1269mAh png/csv

98%

$25.95

 $32.93, link Okay but phone can take 1500s Jasper Williams
EVO 4G stock OEM 1500mAh

1443mAh png/csv

96%

$28.34

 $40.90, link As expected OEM delivers John Doward
EVO 4G, AMZER 1800mAh

1422mAh png/csv

79%

$42.15

 $59.94, link Still testing but what a ripoff Carl Willi
EVO 4G, Seidio, oversized 3500mAh

2821mAh png/csv

81%

$27.38

 $77.25, link Not cheap but hey, best mAh Carl Willi
EVO 4G, ebay, oversized 3000mAh       $10.00, combo En route from Hong Kong Steven J. Sromek
Average result of discharge tests from 4.1V to 3.5V, the devices' cutoffs, at 250mA. Procedures for all batteries idendical, fair and square, so stop whining Mugen.
Data of intrigue Remarks
Mugen 1800mAh vs OEM 1500mAh, both new, head-to-head png/csv Despite Mugen's 20% higher claim and 226% price markup, results equal
New OEM 1500mAh vs six month daily used OEM 1500mAh png/csv When used as primary battery, OEM ages 1.3% a month or 7.7% over six months.
Fake OEM #1 and No name #1 png/csv V / aH congruent, suggests this counterfeit and this no name share manufacturers.
Traffic to this site? About 25563 pageviews plus 0 views of the data on the XDA forums (N1, TP2).

A word on counterfeits. An article I wrote on fakes. Here's a provocative follow-up. Hmm, sounds familiar. Hey I just bought (and started battery testing) a Nexus One!
What's wrong with this picture? Mugen engineers to me: "These numbers are meaningless." Seidio defeating Mugen in claimed versus actual and in cost per amp hour (see table).
Don't understand everything or want to express your emotions? Good thing we've got a forum for that. HTC's 2150mAh for TP2 clocks in at 2150mAh! What are the odds?
Just cranked out an angry rant about lack of battery juice innovation. I'm looking for a full-time job in NYC so go here to contact me and I'll give you my resume, portfolio and gratitude.

If this data got you excited and you want to vent, go here. Post something while you're there. But please, try to resist spamming, c'mon.

Thank you Radical RC for supplying me with the West Mountain Radio's Computerized Battery Analyzer III. Hope this helps all of you.

If you want to publish any of this data on your own website for commercial purposes (meaning if you're selling something, not if you're recommending a battery to someone in a forum or whatever), do me a favor and ask first. Ahh screw it, just post the data, public domain baby.

Doug Simmons