What "C" lipos to use?

[MrTross]

Running a 13.5t brushless system on my touring car on a local club track quite windy with a small strait what "C" rating lipos would you surgest to use as allot of people seem to use 65c + but been told I don't need that much?

[haris]

what is the make and specs of your ESC ?

[dale]

Short version; anything at 40C or above will be fine.


Long version...

The motor will only draw the current that it requires; a battery can't force extra current into the motor. So, as long as the current rating of the battery is more than the motor requires, the motor will achieve its maximum and there's no need to spend money going any higher on C-rating.

Even with boost on a high-grip surface a 13.5T won't pull much more than about 80 amps (outdoors my boosted 10.5T only pulls 70A maximum). If the battery is 5000mah capacity, this means you need a battery of just 16C (80A / 5Ah = 16C).

The problem is that all the 'C' numbers on the batteries are total lies, because you can definitely tell the difference between a 20C and a 40C battery, which you wouldn't if they were really rated this high. But even with 10.5 boosted I can't feel (or see on the stopwatch or data-logger) the difference between 40C and 60C. So maybe the quoted numbers are about double what they are actually capable of. So for most racing, 40C is enough.

[MrTross]

The speed controller is a hobbywing xtreme stock 60a with a 13.5t motor

[Chrisfoster1971]

interested in comments also as just got a second hand blitz with a bullimore 8.5t motor, not sure of exact model of hobbywing esc but it aint huge. Was looking at VPracing/Vapextech Lipos to install but dont want to waste cash on stuff if it aint gonna be right