Replacement Battery

Has anyone found a good replacement battery for the MAXX? The original bit the dust after about 2.5 years. I replaced it with "new" old stock battery which was not much better. It was about the same age as the one it replaced and was not much better. I bought an Onite battery from Amazon. Its better than the "new" old stock battery but not nearly as good as the one that came with the phone. The Battery Monitor Widget app shows it's capacity at 2500maH not the 3500maH that the original had.

Is there a reliable aftermarket battery supplier out there??

Thanks
John