Comments on: Li-Polymer: to charge, or not to charge http://www.intelliot.com/blog/archives/2005/08/25/li-polymer-to-charge-or-not-to-charge/ Thoughts, opinions and fascinating discoveries by Elliot, a student at USC Fri, 16 May 2008 02:20:57 +0000 http://wordpress.org/?v=2.5.1 By: Geek Mother http://www.intelliot.com/blog/archives/2005/08/25/li-polymer-to-charge-or-not-to-charge/#comment-403964 Geek Mother Wed, 05 Mar 2008 20:22:23 +0000 http://www.intelliot.com/blog/archives/2005/08/25/li-polymer-to-charge-or-not-to-charge/#comment-403964 yeah, use it as if it were just Li-ion. Pretty much the same to be honest yeah, use it as if it were just Li-ion. Pretty much the same to be honest

]]> By: B Burton http://www.intelliot.com/blog/archives/2005/08/25/li-polymer-to-charge-or-not-to-charge/#comment-311313 B Burton Wed, 12 Sep 2007 12:39:28 +0000 http://www.intelliot.com/blog/archives/2005/08/25/li-polymer-to-charge-or-not-to-charge/#comment-311313 The articles at this site http://www.batteryuniversity.com/partone.htm should be of interest to you if you haven't found them yourself already. Lithium- Ion Batteries do not have memory like the Nickel-Cadmium chemistry does. It is however important to let the battery drop low enough to cause the device to cut off at least once every 30 cycles. This ensures that the batteries internal safety switch resets, which is supposed to add life to its over all cycles. Lithium batteries don't mind if you use them for a short time and then recharge to maximum. The internal resistance of the lithium ion battery is moderate unlike its counter parts the alkaline and nickel based batteries which is high. Note that the lead -acid batteries found in cars and other devices have the lowest internal resistance which means they can run longer and deliver more of the power stored in them per second there just bulky and toxic. However lithium based batteries have the highest stored energy 4.2v(initial charge) per cell instead of 1.5 volts per cell as with other batteries. (standard AA type) There flat construction is possible due to extremely thin layers stacked upon each other instead of being rolled into a can. Perfect for cell phones and PDA's, not so good for power tools and medical equipment. Lithium Ions exhaust rapidly under heavy current loads and the battery can vent gas if operated or left in temperatures over 120F and if charged improperly. (ie. hot cars with windows rolled up) An internal safety circuit is built into them to insure the battery is forced open in case of overheating to prevent it from corroding internally which can destroy it. Solid lithium plating can occur in excessive temperatures or if foreign metals like copper, iron and others left over from manufacture come in contact with the active materials inside. If the battery is left in a "dead" state for to long then a recharge is no longer possible from a regular wall or car charger. That happened to my AT&T 8525 when I first bought it from the previous owner. The phone was brand new and he had only had it for about a week. When I bought the phone, it wouldn't power on at first. I figured "Oh well, it probably just needs to be recharged." I was mad when the next morning I woke up and had, had the phone on charge all night but the phone still would not turn on. I had used the charger that plugs in the wall, and it was charging at .5 amps or .5C. I was beginning to think I had bought a piece of crap. I then used the USB charger that links it to my computer (a USB cable with a special end for the phone) to charge it, the battery was so dead it wouldn't even turn on with it plugged to the computer. I said, "Well I will let it sit for an while and see what happens" Later on I checked it and the light had went from red to orange/yellow. I pushed the power button and BAM it came to life. I could then see the charge status of the battery and it was at 90% and at 100% the charge light turned green. When I first got the phone I didn't know anything about lithium ion polymer or lithium anything really. It was after that incident I became interested in there construction, and chemical composition. The site I learned all this from and more is at the top of this reply. The articles at this site http://www.batteryuniversity.com/partone.htm should be of interest to you if you haven’t found them yourself already. Lithium- Ion Batteries do not have memory like the Nickel-Cadmium chemistry does. It is however important to let the battery drop low enough to cause the device to cut off at least once every 30 cycles. This ensures that the batteries internal safety switch resets, which is supposed to add life to its over all cycles. Lithium batteries don’t mind if you use them for a short time and then recharge to maximum. The internal resistance of the lithium ion battery is moderate unlike its counter parts the alkaline and nickel based batteries which is high. Note that the lead -acid batteries found in cars and other devices have the lowest internal resistance which means they can run longer and deliver more of the power stored in them per second there just bulky and toxic. However lithium based batteries have the highest stored energy 4.2v(initial charge) per cell instead of 1.5 volts per cell as with other batteries. (standard AA type) There flat construction is possible due to extremely thin layers stacked upon each other instead of being rolled into a can. Perfect for cell phones and PDA’s, not so good for power tools and medical equipment. Lithium Ions exhaust rapidly under heavy current loads and the battery can vent gas if operated or left in temperatures over 120F and if charged improperly. (ie. hot cars with windows rolled up) An internal safety circuit is built into them to insure the battery is forced open in case of overheating to prevent it from corroding internally which can destroy it. Solid lithium plating can occur in excessive temperatures or if foreign metals like copper, iron and others left over from manufacture come in contact with the active materials inside. If the battery is left in a “dead” state for to long then a recharge is no longer possible from a regular wall or car charger.

That happened to my AT&T 8525 when I first bought it from the previous owner. The phone was brand new and he had only had it for about a week. When I bought the phone, it wouldn’t power on at first. I figured “Oh well, it probably just needs to be recharged.” I was mad when the next morning I woke up and had, had the phone on charge all night but the phone still would not turn on. I had used the charger that plugs in the wall, and it was charging at .5 amps or .5C. I was beginning to think I had bought a piece of crap. I then used the USB charger that links it to my computer (a USB cable with a special end for the phone) to charge it, the battery was so dead it wouldn’t even turn on with it plugged to the computer. I said, “Well I will let it sit for an while and see what happens” Later on I checked it and the light had went from red to orange/yellow. I pushed the power button and BAM it came to life. I could then see the charge status of the battery and it was at 90% and at 100% the charge light turned green. When I first got the phone I didn’t know anything about lithium ion polymer or lithium anything really. It was after that incident I became interested in there construction, and chemical composition. The site I learned all this from and more is at the top of this reply.

]]> By: F Ross http://www.intelliot.com/blog/archives/2005/08/25/li-polymer-to-charge-or-not-to-charge/#comment-15793 F Ross Thu, 29 Sep 2005 17:23:15 +0000 http://www.intelliot.com/blog/archives/2005/08/25/li-polymer-to-charge-or-not-to-charge/#comment-15793 MIght be a bit late in responding...... You can treat a "Li Polymer" battery the same was as Li-ion. I.e. you don't have to let it run down. Li Polymer is largely a marketing ploy. For all practical purposes your battery is Li-ion. MIght be a bit late in responding…… You can treat a “Li Polymer” battery the same was as Li-ion. I.e. you don’t have to let it run down. Li Polymer is largely a marketing ploy. For all practical purposes your battery is Li-ion.

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