Lithium battery for made in China facial and nose hair trimmer? - Page 1
Forum section: electronics / general

author: Boris_yo
author_rank: Frequent Contributor
timestamp: April 19, 2014, 02:55:47 pm
content: You know those gadget things from China, right?I have 2 of those you see below picture:What I have noticed is that they are more effective on lithium AAbatteries that alkaline AA batteries.But I am concerned about using lithiums in them.Are lithiums safe to use in such gadgets?I know that alkalines corrode, but what happens with lithiums?Thanks.

author: SeanB
author_rank: Super Contributor
timestamp: April 19, 2014, 03:07:38 pm
content: Disposable use once Lithium batteries are fine, the usual caveat about not shorting them, leaving flat ones in the unit or burning them still applies. If you recharge them, try to use them for welding or crush with a hammer you might have an issue, but in those cases your long nasal hair will not be the thing being trimmed at the same time.If you are worried try tweezers and pull.If very brave go to the salon and have them waxed, or use hair removal gel.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: April 19, 2014, 04:09:09 pm
content: Quote from: SeanB on April 19, 2014, 03:07:38 pmYou are not writing clearly today...I was referring to AA lithium batteries like of Energizer. You mentioned they can be rechargedbut I never knew they can actually. Is this true?

author: SeanB
author_rank: Super Contributor
timestamp: April 19, 2014, 04:48:28 pm
content: Recharging them will plate out lithium metal, and then it will grow a dendrite through the separator and make a flaming battery. They are not rechargeable at all. Same for drawing too much cureent which overheats the internal current carrying plates, or damaging them which shorts them out. All result in a fast discharge, evolution of heat and gas which results in an explosive release of the inner contents.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: April 19, 2014, 05:45:27 pm
content: Quote from: SeanB on April 19, 2014, 04:48:28 pmNot sure why you assumed I want to recharge them.And drawing too much current? Not a case with suchsmall gadgets.

author: theatrus
author_rank: Frequent Contributor
timestamp: April 19, 2014, 06:59:08 pm
content: Quote from: SeanB on April 19, 2014, 04:48:28 pmThe Energizer LiFe (1.5-1.8V) cells are really well protected. You can short them out and their safety features work admirably.Under no circumstances should you use a Chinese cell here. A flaming (self ignited due to internal short) battery once rocketed out of a product and almost tanked the small startup.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: April 19, 2014, 07:25:10 pm
content: Quote from: theatrus on April 19, 2014, 06:59:08 pmWhat can you tell me about 14500 and 18650 chinese lithium batteries? I ask in general because you sound like you had experiences with low quality batteries.

author: theatrus
author_rank: Frequent Contributor
timestamp: April 19, 2014, 10:22:58 pm
content: Can't tell much about them, but I would shy away from any discount lithium cell.Note that for LiFeS2 cells, the starting voltage is 1.7V, and they have a much flatter/step voltage curve:http://data.energizer.com/PDFs/l91.pdfFor an unregulated DC motor that will speed it up somewhat.