# Why is 4C quoted as 400 amps

1. Apr 7, 2010

### robinfisichel

http://evcomponents.com/cscart/index.php?dispatch=products.view&product_id=29862 [Broken]

for example

I thought Coulombs SI units was A.s so for 1 second 4C = 4A, am i wrong?

Last edited by a moderator: May 4, 2017
2. Apr 7, 2010

### stewartcs

The C is probably for Roman Numerals...which means 100. Hence, 4C = 4 x 100 = 400, 12C = 12 x 100 = 1200.

CS

Last edited by a moderator: May 4, 2017
3. Apr 7, 2010

### mheslep

No the 'C' in the battery rating refers to battery capacity. '1C' is synonymous with the 'amp-hour' rating of the battery, and is the the rate at which the battery totally discharges in something a little less than one hour. For the OP's example, 4C=400A means the battery would supply 400A for 1/4 hour, but one needs to see the battery discharge curve for tje exact meaning as the curves are not linear.

http://www.batteryuniversity.com/partone-16a.htm [Broken]

Last edited by a moderator: May 4, 2017
4. Apr 8, 2010

### robinfisichel

Thanks mshelp! You seem to be answering a lot of my questions lately! Im not sure i completely understand but I get the idea now, C is NOT coulombs!

Last edited by a moderator: May 4, 2017