I have been through a couple of different brand batteries for my Captivate.
I tried the OEM that was listed at the top thinking it would be good quality at a little higher price. I was wrong the battery gave 75% battery life then the original battery that came with the phone.
I tried 2 batteries and charger deal and that was a waste a time. I didn't think it was going to be good the batteries didn't even have a brand label. The price seemed a little low to be true.
Next I purchased the RND Power Solutions Brand and it actually worked out.
The first 2 weeks I was swapping the batteries to measure the difference in battery life.
I do think the RND Power Solutions brand out performed the original a little.
It all depends on the daily use.
I am satisfied with my purchase and would buy again from this company.
If anyone is interested here is the battery
Amazon.com: Premium Lithium-Ion Battery (EB575152VA) for Samsung Galaxy S (Epic 4G D700 (SPH-D700), Captivate i897 (SGH-i897), Vibrant T959 (SGH-T959), and GT-i9000) and Samsung Focus i917 (SGH-i917): Electronics