> NiMH cells need a "forming" charge in my experience. I do it with a > current source at 0.1C for 14H. This is done *without* end-of-charge > detection of any kind. Just a straight-up current source. The cells will > be overcharged a little, but they can handle it at this current. > > I discharge the batteries first to around 1.0V at 1C with a constant > current load, then do the forming charge above. I repeat this a few > (4-5) times, and then use the batteries. So far they are holding up > well. These are Eneloops purchased locally at full price, by the way, so > they're most likely genuine. (1) I'd be extremely interested in knowing what sort of voltage you get at around 400 mA discharge when anywhere between say 25% and 75% of full capacity. 400 mA would require ABOUT 3 Ohms - but anything from about 2.7 to 3.9 Ohms would probably suffice. (2) Mine were purchased at a retail store from a company that has a number of stores and that is a market leader in computer & peripherals and accessory sales. Effectively they WERE full price and sold on the open market in direct store-front competition. Under those conditions "cheap" should mean "competitive" and not "fake". IF the batteries are fakes they are very well done. I'm reasonably sure that they are. Still testing. I am well used to NimH charging with various termination means. I use high capacity cells for camera use and note the capacity rise over the first few cycles which is widely mentioned in the literature. My experience with modern high capacity cells is that they are at about full capacity by the 3rd full cycle. The ones I am testing are on about their 5th whole cycle. (Mainly 2A charge and 400 mA discharge as that matches available Sanyo data). Being LSD (allegedly) they came reasonably well charged, but not as high as I'd expect. So far none of my cells under test has quite reached guaranteed minimum rated capacity. For solar lighting use I usually use lower capacity cells. On occasion I've carried enough of them with me (100's) that security interest was the final nail in missing a flight. ___________________________________ Sanyo spec is at 20C. I'd be "close enough" but not measured. Battery temperature rise is moderate on charge and low on discharge. Sanyo data says Vbat should be ABOUT 1.28V falling to 1.25V across the 75% to 25% capacity range at 400 mA, whereas I'm seeing typically 1.225 or less. More in 1st 1/4. eg typical only. Odd mAh are due to "walk past tester and take a reading" sampling method. Time for a logger :-). mAh Vbat 72 1.31 260 1.24 960 1.225- 1650 1.14 Differences are "subtle" but consistent and noticeably separated from Sanyo data. Vbat on charge at 2A is noticeably lower than Sanyo data (a good thing all else being equal. Alas, all else isn't). Russell --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .