Comments on: Multimeter experiment with voltage and current http://www.andybrain.com/sciencelab/2008/01/01/multimeter-experiment-with-voltage-and-current/ Science Experiments for Kids, Parents and Teachers Sun, 23 May 2010 06:42:39 +0000 hourly 1 http://wordpress.org/?v=3.0.4 By: Andy Kaiser http://www.andybrain.com/sciencelab/2008/01/01/multimeter-experiment-with-voltage-and-current/comment-page-1/#comment-157 Andy Kaiser Tue, 17 Feb 2009 03:58:31 +0000 http://www.andybrain.com/sciencelab/2008/01/01/multimeter-experiment-with-voltage-and-current/#comment-157 Hi Randall, Thanks for the information. I'm not sure I agree with your assessment of danger, however: What standard battery and wire combination can you come up with that will explode or cause a fire? Or perhaps, I should prefix the article with something like "perform these tests on a AA or AAA or watch battery only". Andy Hi Randall,

Thanks for the information. I’m not sure I agree with your assessment of danger, however: What standard battery and wire combination can you come up with that will explode or cause a fire? Or perhaps, I should prefix the article with something like “perform these tests on a AA or AAA or watch battery only”.

Andy

]]> By: Randall Francis http://www.andybrain.com/sciencelab/2008/01/01/multimeter-experiment-with-voltage-and-current/comment-page-1/#comment-156 Randall Francis Tue, 17 Feb 2009 02:40:10 +0000 http://www.andybrain.com/sciencelab/2008/01/01/multimeter-experiment-with-voltage-and-current/#comment-156 Energizer battery manufacturer has a website with a datasheet for every battery they have. The alkaline tiny AAAA cell and the alkaline huge D cell both have an internal resistance of from 150 to 300 milli-ohms. 1.5V with a 300 milli-ohms resistance is a current of 5A into a short circuit and is a current of 2.5A into a load of 300 milli-ohms when the battery cell is brand new. Energizer Ni-MH rechargeable cells (their C and D cells have a little AA cell inside) have an internal resistance of only 30milli-ohms so their max current is almost 40A for a moment. __________________ Uncle $crooge Energizer battery manufacturer has a website with a datasheet for every battery they have.

The alkaline tiny AAAA cell and the alkaline huge D cell both have an internal resistance of from 150 to 300 milli-ohms.
1.5V with a 300 milli-ohms resistance is a current of 5A into a short circuit and is a current of 2.5A into a load of 300 milli-ohms when the battery cell is brand new.

Energizer Ni-MH rechargeable cells (their C and D cells have a little AA cell inside) have an internal resistance of only 30milli-ohms so their max current is almost 40A for a moment.
__________________
Uncle $crooge

]]> By: Randall Francis http://www.andybrain.com/sciencelab/2008/01/01/multimeter-experiment-with-voltage-and-current/comment-page-1/#comment-155 Randall Francis Tue, 17 Feb 2009 02:33:40 +0000 http://www.andybrain.com/sciencelab/2008/01/01/multimeter-experiment-with-voltage-and-current/#comment-155 Shorting out fully charged batteries is not a good pratice since thet can explode or cause a fire depending on the type of battery and size or wire used. I would recommend removing this from your web site before kid hurts them self. Shorting out fully charged batteries is not a good pratice since thet can explode or cause a fire depending on the type of battery and size or wire used. I would recommend removing this from your web site before kid hurts them self.

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