Linked by Thom Holwerda on Wed 22nd Jul 2009 18:20 UTC, submitted by tupp
Apple It seems Apple is on a roller coaster ride this week, going from bad news to good news, back to bad news again. A local television station from Seattle, US, forced the Consumer Product Safety Commission via the Freedom Of Information Act to hand over an 800-page report about fire hazards posed by Apple's iPod music players. Experts on consumer safety agree that it's time Apple makes public statements about the fire hazards posed by iPods.
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Lithium ion batteries
by JacobMunoz on Thu 23rd Jul 2009 02:53 UTC
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About a year ago, I purchased an electric scooter powered with really fancy Li-ion "nano-phosphate" LiFePo4 type:"rediculous" batteries. These are cells from A123 Systems, and they're scarry powerful (each is 3.3V @ 2300 mAH with 70A continuous drain or 120A in 10sec pulses). Now, I've been riding the scooter for a while - and these cells have really taken a beating in their lives. But I have yet to find any article about these types of cells exploding (probably helps that their laser-welded). They're also designed for industrial apps and hybrid vehicles, so I'm sure the chemistry had to be made a bit safer.

I recently bought 20 of the same '26650A' LiFePo4 from an eBay'er in China, so I'll be able to replace the existing unit with fresh cells. It also turned out to be 5 more cells than the original contains, so I'll be able to add about 25% more charge to my scooter.

But these cells are honestly terrifying - not that I've blown anything up yet, but 70 amps of continuous current per cell (5 cells series x 4 stacks in parallel)... mmmmm.. that about 280 amps @ 18VDC of kill your darn self if you're not careful. You can buy the cells from a 'developers kit' dealer that sells A123 cells with handy tabs, but they're really expensive. My cost for 20 was 80$ + 40$ s/h, waaaay cheaper than the 6 for $120 brand new. The ebay seller said they came from DeWalt 36V battery packs, and they do seem to be very fresh (good V, killer A) and essentially unused.

Needless to say, I will be soldering them with a full array of rubber protective gear.

Reply Score: 2

RE: Lithium ion batteries
by smashIt on Thu 23rd Jul 2009 09:36 in reply to "Lithium ion batteries"
smashIt Member since:

About a year ago, I purchased an electric scooter powered with really fancy Li-ion "nano-phosphate" LiFePo4 type:"rediculous" batteries.

LiFe cells can't explode like the old ones (the Fe is some kind of inhibitor for explosive reactions)
but as good as all modern cells have modified chemicals to reduce the risk of an explosion

Reply Parent Score: 2