Timeline for Why can different batteries with the same voltage send different currents through the same object?
Current License: CC BY-SA 2.5
17 events
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| Apr 13, 2017 at 12:46 | history | edited | CommunityBot |
replaced http://skeptics.stackexchange.com/ with https://skeptics.stackexchange.com/
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| Aug 9, 2013 at 22:55 | answer | added | Anthony X | timeline score: 1 | |
| May 26, 2011 at 22:00 | comment | added | dmckee --- ex-moderator kitten | You can get an arc from a 9V "flashlight" battery if you use a NiCd or Li-ion cell. Been there. done that. | |
| May 26, 2011 at 21:39 | answer | added | joebanana | timeline score: -5 | |
| Apr 12, 2011 at 13:27 | vote | accept | Casebash | ||
| Apr 2, 2011 at 17:15 | comment | added | David Cary | There's a usually unspoken rule of thumb when designing stuff with batteries: The people designing the battery promise they will keep the voltage within a certain range as long as the the current pulled from the battery is less than some maximum current. The people designing other stuff promise to pull less than some maximum current from the battery as long as the voltage applied is in the normal operating range. When these promises are violated, the convenient simple rules of thumb we use ("batteries put out a constant voltage") don't work anymore. | |
| Apr 2, 2011 at 15:42 | history | edited | Georg | CC BY-SA 2.5 |
edited title; edited title
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| Apr 2, 2011 at 14:53 | comment | added | David Cary | The cold cranking amperes (CCA) rating of a starter battery is defined as the amount of current a battery can deliver while maintaining at least 1.2 V per cell (under certain conditions) -- that is, maintaining at least 7.2 V across the terminals of the battery, which is much less than the 12.6 V fully-charged open-circuit voltage or the 11.9 V fully-discharged open-circuit voltage of the same "12 V" battery. I suspect the actual voltage across that little 12 V during this experiment is much lower. | |
| Apr 2, 2011 at 14:45 | comment | added | Omega Centauri | And you can always decrease the effective internal resistance by ganging several similar batteries together in parallel. Put twenty car batteries together in parallel, and the short circuit voltage can become frighteningly high. | |
| Apr 2, 2011 at 14:14 | comment | added | Zo the Relativist | And beyond what everyone else said, it should be explicitly stated that Ohm's law isn't a universal law of nature, like Newton's law of gravity, or the Maxwell equations. It is an empirical observation about how some materials behave in some situations. | |
| Apr 2, 2011 at 10:02 | answer | added | Georg | timeline score: 9 | |
| Apr 2, 2011 at 8:18 | answer | added | Martin Gales | timeline score: 3 | |
| Apr 2, 2011 at 7:47 | answer | added | Edward | timeline score: 3 | |
| Apr 2, 2011 at 7:30 | comment | added | anna v | You could check this article in wikipedia en.wikipedia.org/wiki/Battery_%28electricity%29 , "battery capacity and discharging". | |
| Apr 2, 2011 at 5:00 | history | edited | Casebash | CC BY-SA 2.5 |
edited title
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| Apr 2, 2011 at 4:54 | history | edited | Casebash | CC BY-SA 2.5 |
added 52 characters in body; added 54 characters in body
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| Apr 2, 2011 at 4:42 | history | asked | Casebash | CC BY-SA 2.5 |