Choosing a LiPo battery, understanding C rating

[KyleRC]

I have been wondering for a while. Does anyone know if the C RATING effects the temperature of the electronics but NOT the battery.

 

[WoodiE]

I have been wondering for a while. Does anyone know if the C RATING effects the temperature of the electronics but NOT the battery.

A higher C rated battery will not make your motor run cooler. A higher rated C battery MIGHT run cooler with a higher C rating though. Thought being if you have a low C rated pack in your RC that is drawing more amps than the pack can comfortably supply the battery temp will go up, in this case a higher C rated pack would result in a cooler running battery.

Think of it this way, amps are pushed not pulled. Since the C rating of a battery is essentially the rate of which it can discharge - if you have a 5,000mah 30c battery it can have 150 amps pulled from it. Say your motor is pulling 100amps - the 30c battery is more than sufficient. Now lets say you have a 5,000mah 40c battery that's capable of 200 amps, your motor will still only pull 100 amps so the extra 100amp doesn't make a difference to your motor as your motor has no idea what your battery C rating is rated at.

A higher C rating might possibly keep your battery a little cooler but will not have much effect on your motor.

 

[KyleRC]

A higher C rated battery will not make your motor run cooler. A higher rated C battery MIGHT run cooler with a higher C rating though. Thought being if you have a low C rated pack in your RC that is drawing more amps than the pack can comfortably supply the battery temp will go up, in this case a higher C rated pack would result in a cooler running battery.

Think of it this way, amps are pushed not pulled. Since the C rating of a battery is essentially the rate of which it can discharge - if you have a 30c battery it can have 150 amps pulled from it. Say your motor is pulling 100amps - the 30c battery is more than sufficient. Now lets say you have a 40c battery that's capable of 200 amps, your motor will still only pull 100 amps so the extra 100amp doesn't make a difference to your motor as your motor has no idea what your battery C rating is rated at.

A higher C rating might possibly keep your battery a little cooler but will not have much effect on your motor.

Thanks. I was thinking about ordering a gens ace 3s 45c 5000mah battery and didn't want my temps to go up any more than my old 20c 3s 6400mah.

 

[WoodiE]

Thanks. I was thinking about ordering a gens ace 3s 45c 5000mah battery and didn't want my temps to go up any more than my old 20c 3s 6400mah.

Nope, you shouldn't have any problems at all. In fact some manufacturers tend to overrate the C rating on their batteries so it's better to go with a higher C rating than you think you need rather "just enough" or a lower rating.

Not saying Gens Ace overrates their C rating - just saying in general.

Just remember that amps is the most important thing to keep in mind and how you can calculate that is by using this formula:

mAh * C-Rating = AMPS

Example:
5000mAh * 45c = 225,000 (225 amps)
6400mAh * 20c = 128,000 (128 amps)

 

[KyleRC]

Nope, you shouldn't have any problems at all. In fact some manufacturers tend to overrate the C rating on their batteries so it's better to go with a higher C rating than you think you need rather "just enough" or a lower rating.

Not saying Gens Ace overrates their C rating - just saying in general.

Just remember that amps is the most important thing to keep in mind and how you can calculate that is by using this formula:

mAh * C-Rating = AMPS

Example:
5000mAh * 45c = 225,000 (225 amps)
6400mAh * 20c = 128,000 (128 amps)

How much do you think batteries tend to be over rated?

I was wondering if it was ever possible to have a C rating that's too high?

 

[zukicidal]

I thought the c rating basically effects how responsive your power delivery is. Like a 20c will provide less torque at start up than a 30c. I keep reading how the guys with 30c and up are breaking driveshafts, etc. I have no issues with my 5000 20c.

 

[xlDooM]

Your battery, ESC and motor can all restrict the current used by your RC and therefore maximum torque. For a stock Amp for example, a battery that can deliver 300A will not be quicker than one that delivers 150A. The motor and ESC just can't use more than ~120A in my experience.

 

[KyleRC]

Is it ok to run a flight battery in my truck it is a gens ace 45c 3s 5000mah i use a 6400mah 20c right now an i want a little more kick.

 

[xlDooM]

Flight and car batteries are the same except car batteries usually come in plastic casing rather than just shrink wrapped. Be careful though, the stock electronics of most ECX trucks will not take your 3s, and even if you have aftermarket 3s capable ESC and motor, most people find it pushes the performance of these vehicles into break-stuff-all-the-time territory.

What RC do you run?

 

[KyleRC]

Flight and car batteries are the same except car batteries usually come in plastic casing rather than just shrink wrapped. Be careful though, the stock electronics of most ECX trucks will not take your 3s, and even if you have aftermarket 3s capable ESC and motor, most people find it pushes the performance of these vehicles into break-stuff-all-the-time territory.

What RC do you run?

I run the ruckus 3s 3000kv and metal drivetrain

 

[Jeb]

I run a 40c 6200 and 45c 5000 in my amp with a 4000kv and have never snapped a driveshaft, although I spin through differentials about every 2 months. I clocked them at 38mph and can't imagine making them any faster. I have to limit throttle to 85% to keep them in control while racing. Any faster is just useless unless you're just running speed tests in straight lines. I run exclusively on gravel and dirt tracks.

 

[KyleRC]

I run a 40c 6200 and 45c 5000 in my amp with a 4000kv and have never snapped a driveshaft, although I spin through differentials about every 2 months. I clocked them at 38mph and can't imagine making them any faster. I have to limit throttle to 85% to keep them in control while racing. Any faster is just useless unless you're just running speed tests in straight lines. I run exclusively on gravel and dirt tracks.

Are those batteries 3s

 

[Jeb]

Are those batteries 3s

No just 2s. I did however have to put a 90c 7200 on my 4x4sct. The motor was asking for more juice than 45c could deliver. I was melting solder and melting deans plugs. I had to turn the throttle endpoint down to 75% to keep from melting things. Trying the new battery in tomorrow's race!

 

[KyleRC]

No just 2s. I did however have to put a 90c 7200 on my 4x4sct. The motor was asking for more juice than 45c could deliver. I was melting solder and melting deans plugs. I had to turn the throttle endpoint down to 75% to keep from melting things. Trying the new battery in tomorrow's race!

Is the amp good for racing

 

[Jeb]

Is the amp good for racing

My son is 10 and has only had his Amp since Christmas and rutinely places first in the kids group. My Amp get's a lot of seconds. The center of gravity is a little high for racing, but I've committed to running it the full season. Mine is extremely modified, but I'm hanging with Losi's, Associated, Tekno, Traxxas, etc. The track owner is wicked impressed with how well my Amp does against race designed machines. I'm still making adjustments, but I see a 1rst place happening by the end of Summer. This little truck has taught me a lot.