Newbie needs help! - Page 2 - Electronic Circuits Projects Diagrams Free

bryan1 · 31st July 2006, 08:33 AM

Well I pulled apart a brandnew laptop battery I got to use the lithium ion batteries for my electronic projects. These batteries are rated at 4.5 volts and 4 amp hours so I've put 3 of them in series to get a 13.5 volt battery pack. All I do to charge them is stick them on my nife batterybank which at night usually sits around 13.5 to 14 volts. I've left that battery pack on the nife batteries for nearly a week after I forgot to take them off and when I did take them off they weren't hot and were sitting on 13.8 volts

. I know this isn't the ideal way to charge a lithuim battery but 12 months down the track that little battery pack is still going strong.
Note I only do this as I know the top voltage my nife batteries can do is 15 volt due to the shunt regulator circuit I made diverts the excess voltage to a dumpload.

OpPoSiTe · 31st July 2006, 10:30 AM

Ok, now im getting confused

:S

audioguru · 31st July 2006, 01:28 PM

I just looked into a Sanyo cell phone's Li-Ion battery. It is rated for 3.6V. Inside it has two cells a little bigger than an AA size in parallel measuring 3.755V (it hasn't been charged for about 6 years) and a very small circuit board packed with ICs and things. I don't know the power adapter's voltage for this phone and I don't know if the electronic circuit inside the battery is its charger.

StopGo · 7th August 2006, 06:16 PM

Really risky idea...

The nokia battery (BL-5C) is a bare bones Li-ion, it has no protective supervisory circuit, if you fail to charge it right then you risk exploding batteries and the *very* nasty stuff inside them getting out.

philba · 9th August 2006, 05:08 AM

dramatic (but poor quality) video of the result from LiPo over charging. http://video.google.com/videoplay?do...60570423705609

article on LIthium battery pack explosion: http://www.cdc.gov/niosh/fire/reports/face9939.html

does your notebook run a little hot? http://www.engadget.com/2006/07/28/a...aptop-ignites/

there are tons of stories out there. don't screw around with lithium batteries.

31st July 2006, 08:33 AM	(permalink)
bryan1 Experienced Member	Well I pulled apart a brandnew laptop battery I got to use the lithium ion batteries for my electronic projects. These batteries are rated at 4.5 volts and 4 amp hours so I've put 3 of them in series to get a 13.5 volt battery pack. All I do to charge them is stick them on my nife batterybank which at night usually sits around 13.5 to 14 volts. I've left that battery pack on the nife batteries for nearly a week after I forgot to take them off and when I did take them off they weren't hot and were sitting on 13.8 volts . I know this isn't the ideal way to charge a lithuim battery but 12 months down the track that little battery pack is still going strong. Note I only do this as I know the top voltage my nife batteries can do is 15 volt due to the shunt regulator circuit I made diverts the excess voltage to a dumpload. __________________ " The only way to avoid human error is to avoid the use of humans"

31st July 2006, 01:28 PM	(permalink)
audioguru Experienced Member	I just looked into a Sanyo cell phone's Li-Ion battery. It is rated for 3.6V. Inside it has two cells a little bigger than an AA size in parallel measuring 3.755V (it hasn't been charged for about 6 years) and a very small circuit board packed with ICs and things. I don't know the power adapter's voltage for this phone and I don't know if the electronic circuit inside the battery is its charger. __________________ Uncle $crooge

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31st July 2006, 10:30 AM	(permalink)
OpPoSiTe New Member	Ok, now im getting confused :S

7th August 2006, 06:16 PM	(permalink)
StopGo Experienced Member	Really risky idea... The nokia battery (BL-5C) is a bare bones Li-ion, it has no protective supervisory circuit, if you fail to charge it right then you risk exploding batteries and the very nasty stuff inside them getting out.

9th August 2006, 05:08 AM	(permalink)
philba Experienced Member	dramatic (but poor quality) video of the result from LiPo over charging. http://video.google.com/videoplay?do...60570423705609 article on LIthium battery pack explosion: http://www.cdc.gov/niosh/fire/reports/face9939.html does your notebook run a little hot? http://www.engadget.com/2006/07/28/a...aptop-ignites/ there are tons of stories out there. don't screw around with lithium batteries.