Michael Latas--
Nice post on LiPoly. I think new comers and thread regulars alike should keep looking at different chemistries. I know I do. Please note the following additions:
LiPoly and LiOn zealots have got to acknowledge the manufacturing risks and factor those into their thinking about market penetration and the acceptance of those chemistries. How would you like to be the property, fire, and casualty underwriter for each of Sony, Valence, and Ultralife all of whom have had major fires at their manufacturing facilities? Buying Lithium batteries may get to be a lot like buying new private aircraft-- they work but over 1/2 the cost is current and future insurance premiums. Even if one buys the notion that a polymer electrolyte is safer in operation, the manufacturers must still handle lithium in dessication rooms. A battery chum once referred to lithium battery experimenters as "war lords": they were deep in the dungeons of the building in bomb proof rooms.
Second, what about cost. All of these Lithium chemistries are way more expensive than NiMh. Let us not forget net vs. gross cost, and net energy density vs. gross energy density, with the difference in each case being due to the need for redundant charge control systems. The 10 cell LION (traitor!) battery I just replaced for my laptop cost $240. Even allowing for a 75% margin along the way to my desk, this is still $6 per cell, or around 4-5x what NiMh might cost (not available as an option on my laptop). And I most assuredly did not get 500 cycles.
Third, despite what these mfgs say, the safety issues ARE NOT RESOLVED to everyones satisfaction. Why are the FAA and the NTSB concerned about *shipping* (let alone using) Lithium batteries by air if they are so dang safe? Why are the computer mfgs lobbying the airlines NOT to put in flight recharging facilities in place if they are so dang safe?
Note that my first and third points are about safety in manufacturing vs. safety in use. LION manufacturing involves highly flammable solvents. LION and LiPoly both inovlve handling the explosive lithium at some point. The third point was getting at safety in use. Apparently these manaufacturers haven't yet convinced some very important folks. |
