Summary: I bought this as a replacement for my Canon EOS and I didn't expect it to do as good as it has. I can take several hundred shots before it goes down one bar. I'm glad I didn't buy an original because I'm getting (if not better) performance, for a fraction of the price.
Summary: The Lenmar DLC511 I bought in June 2012 just died (as of Oct. 2013). It no longer holds charge. So this battery only lasted me 1 year and 4 months. Although it is probably out of warranty, and Lenmar is probably not on the hook for any liability, I must point out that this is not acceptable life for a rechargeable battery. The Canon battery I bought back in 2008 is still usable (after 5 years).
Summary: In the past I have been skeptical of "off-brand" batteries, however as my cameras age I become reluctant to spend the money on the Canon brand battery. So far, the Lenmar has worked perfectly well. Please be aware, however, that the 'Lenmar' is ever-so-slightly smaller than the real deal. [Perhaps for patent reasons?] As a consequence, the plastic "shield" that covers the contacts on the Canon battery won't fit the Lenmar - it falls off.
Summary: I might of gotten a bad battery. This thing would not hold a charge at all. Showed it took 100%, then when used the next morning it was empty. Again it might have just been the batch but this one is no good.
Summary: I've had good luck with Lenmar products in the past and this one is no different. Great capacity! I haven't actually counted how many photos it allows me to shoot before needing a charge but I can easily go for 2 weeks shooting here and there (somewhere between 500-1000) without having to charge my Canon 20D.
Summary: I purchased two Lenmar DLC511 batteries for my Canon EOS 50D and they both died after about 2 uses. Seems like they had a bad lot. But how can you return something like this? I'm not sure what I can do.
Summary: I purchased five of these over the past two years for my 50D/5D cameras. Even the oldest one still works like new and they have all worked as well as the original OEM Canon battery. I have been very impressed with these batteries and recommend them to other photographers. The value cannot be beat. If you are looking for an extra or replacement battery for your camera, this one is a great product and even better value.
Summary: you can find batteried for a little less, but the lenmar have always treated me well and not given any firmware nagging like some other generics can. does not have the full 1500mAh Capacity, more like 1200, but still decent.