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Thread: ~~lipo help please~~

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Old 11-25-2009, 10:26 PM   #1
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Arrow ~~another lipo question~~

ok im thinking of getting a 5000mAh 7.4V 15C LIPO li-po Battery but all the crawler guys i see have one with a higher C rate like 20C or 25C can anyone help me with understanding this and will it work my ESC is 60amp if that helps at all i dont know.:?

Last edited by 73formulabird; 12-02-2009 at 07:59 PM.
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Old 11-25-2009, 10:34 PM   #2
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15c will work with a 5000mah batt. No one I know runs anywere near that big a batt in their crawler. 1500mah is plenty enough for 45min+ running most the time. I use about 200mah+ per 5min on course. The smaller the batt the more c ya need.
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Old 11-25-2009, 11:29 PM   #3
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thanks but i still dont get the 15C 25C thing????what is it
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Old 11-26-2009, 12:20 AM   #4
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c rating is the batteries safe discharge rate. the discharge amperage is a function of c rating and capacity.

discharge rate= c rating X capacity in amps

using a 2000 20c pack for example, that would be 2.0amp hours X20 = 40 amps. or better yet, 5.0 ah (5000mah) X 15c = 75 amps.

now as far as discharge rate of the battery goes, the higher the better, however you get to a point were more is useless. with a crawler you dont need much, lots of people run 1350mah 25c packs (33.75 amps discharge) with no issues. runtime and size are bigger things to worry about with a crawler, but keeping c rating in mind is impotant. i just set my friends truck up for some 1800mah 30c lipos, plenty of discharge rate and gets 45 minutes on a pack.
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Old 11-26-2009, 12:27 AM   #5
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Its the amperage discharge, the first number is constant and the second number is the burst amperage. I think a 7t puller(pull's high amperage) needs 30c battery. I'm running a 1350ma 25c battery 3s(3cells 11.1v) each cell is 3.7 volts. I ran 3 cousres in a comp. I have a Tekin FX R and a 45t motor. Each course was 7min long and had 700ma left. Hope that helps.
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Old 11-26-2009, 01:53 PM   #6
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The C rating is a disharge rating. The higher the C, The more current can be pulled from the pack.
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Old 12-02-2009, 07:58 PM   #7
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one more question what if i wire 2 batteries in series to double run time will the c rating double??????
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Old 12-02-2009, 08:18 PM   #8
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I found this on Youtube, it kinda makes it easy-ish to understand

http://www.youtube.com/watch?v=_J9qCyN7urk
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Old 12-02-2009, 09:24 PM   #9
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Quote:
Originally Posted by 73formulabird View Post
one more question what if i wire 2 batteries in series to double run time will the c rating double??????
wiring in series will double your voltage, wiring in parallel will double your mAh and will also double your discharge rating
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Old 12-03-2009, 12:16 AM   #10
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you never change the c rating, thats something thats built into the cells. a 20c pack is always 20c. when you wire in parallel you do double the amount of amps you can pull from it. using 2000mah 20c 7.4 volt for an example

in series- 2000mah, 20c 14.8 volts- safe to pull 40 amps
parallel- 4000mah, 20c, 7.4 volts- safe to pull 80 amps

c rating is fixed, max discharge rate is C x mah /1000
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