These batteries were nearly fully-chareged already when received. I've used several sets of the Ansmann 2850s in my power-hungry camera for th epast 4-5 years and two sets last at least two years (at which point I use them in a less-hungry cmera) of near-daily use, swapping them out for charging as needed, with one set kept on maintenance-charge while the other is in-use so I'm never 'waiting' for charged batteries.I decided to try this "slim line" version for the first time -- not because of the 0.15mm smaller diameter (not an issue with my cameras tho sometimes an issue in some professional transmitting microphones) -- since they are fully rated at 2850mAh and for high/continuous current drain applications. Whereas the 'regular diameter' Ansmann 2850s might only be 2650 (if you read the fine print), this slim-line 'pro' version is fully rated at 2850mAh and tho I'm still using the first set I charged, so far they have lasted for three days [edit: 5 days now] of daily intermittant use and the camera still shows as full-charge, so I'm satisfied these are a good choice. If that turns out to not be the case longer term, I'll update this review, but I fully expect these to be up to he task.Btw, I've tried other 'big-brand'-name and also some lesser known 2900s and 3000mAh NiMh in the past and none could keep up with these Ansmanns, especially in cold weather and that is based on the regular 2850 (2650 min) Ansmanns I've used. There is clearly a rating game with NiMh batteries as borne out by controlled test reviews I've read but these Ansmann Slim Lines seem to be one of the few (and possibly the only 2800+rated) ones that actually test and perform as stated. It seems that ones rated at below 2500 are more likely to actually meet or come close to meeting their ratings but I am not aware of any rated at/over 2700 mAh that consistently do, except for these. If I ever find any I will surely try them since actual performance is what matters to me, not bogus marketing numbers that might occasionally be true under certain unrealistic conditions. In short these Ansmanns do consistently deliver in the real world.As with all NiMh, their performance (total true capacity and idle charge-bleed rates) do begin to decline in short order but the Ansmanns have proven satisfactory even after two full years of daily use -- when they get relegated to a less hungry camera (for another 12-18 months). I see lots of talk of good experience with Enerloop but, while I like the Enerloop idea, they simply do not have anywhere near the capacity/performance of these -- even their highest rated.In short these have become my standard-bearer NiMh battery and if another comes along that should prove better I'll be the first to switch -- real-world reliable performance is all that matters to me....
