alan smith wrote: > OK..lets look at it this way. I have a new product to design. Its not really a portable device like a cell phone, more of laptop but much less power requirements. Balancing costs vs safety vs what the product manager wants or needs......should I attempt to convince them that NiMH is the best way to go? Ive taken over this from a now departed engineer so there is some history that I am not really privy to, but I did make mention that charging Li-Ion is a tricky thing to do and they all said...yes yes we've been made aware of....etc. They also want fast charging of the cells if possible. > There's more to this than meets the eye. Some battery pack makers will insist that the chargers to be used meet engineering standards. There are several NiMH charger chips that qualify well; LT has several. I suggest that your redesign include the charger as part of the product; that precludes the user putting a raw wallwart on it and blowing it up. NiMH's fast charge quite well, but temperature MUST be monitored. Most chargers handle this properly. The switching type are particularly nice, because they eliminate charger pass-element heat losses. The NiMH knee is no more complex to handle than the Li-Ion knee (dip at end-of-charge point). BTW, I think I have seen some reputable firms offering 3300mAH 'AA' cells. Sanyo and Sony have very good cells. --Bob > Bob Axtell wrote: Yes. Some variants of NiMH are very strong (3000maH in 'AA' size, for > example). They have > improved monthly since Lithium Ion was released. There have been few (if > any) improvements > in Li-Ion during that same period. > > To use NiMH instead of Li-Ion would require cellphone redesigns all over > the world, and a SLIGHT > increase in weight- but the safety benefits are major. > > > > alan smith wrote: > >> OK...so whats the BEST next choice for power density, etc....if Lithium Ion are not the best....NiMHy ? >> >> >> --------------------------------- >> Stay in the know. Pulse on the new Yahoo.com. Check it out. >> >> > > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist