--===============0024485543== Content-Type: text/plain; format=flowed; charset="gb2312"; reply-type=original Content-Transfer-Encoding: 7bit Li-ion cells are available without built-in protection. You cannot count on it being present. A discharged cell will try to absorb more than the charger ratings, you need something besides the internal resistance of the regulator to assure a safe operation. John Ferrell http://DixieNC.US ----- Original Message ----- From: "microsoftwarecontrol" To: Sent: Tuesday, May 02, 2006 7:10 AM Subject: [EE] stop wasting time on Li-ion and Acid Lead battery charging I recently suddenly realized that Li-ion battery can be simply charged by a 4.2 contant V source adding a max current limit resistant. That means a cheap LM317 for 2A charging or a 5A voltage regulator, plus a 1 Om 5W resistant, will do the job fine. cost is 5 dollar all together. It is sufficient, and has a basis: every Li-ion pack has build in protective pcb already. So, why still bother with the long list of Li-ion battery charging IC? Acid Lead battery is the same story. Am I wrong in this point? -------------------------------------------------------------------------------- > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --===============0024485543== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --===============0024485543==--