Does ?c? rating make a real difference

[The noob guy]

I have smc 6300 135c and 7600 120c and barely notice the difference. Smc has a 7700 150c now and Im eager to try but not sure it will make a difference. Any idea?

[Panchothedog]

Not until you really start pulling the amps. The harder you run them, or the longer you run them down the lower C rated batteries will puff and potentially ruin themselves sooner. Under normal circumstances very difficult to tell the difference.

[NativePaul]

Yes C rate makes a difference a battery capable of a higher C rate will have a lower internal resistance, thus will run cooler for a given load and will sustain higher voltages under higher loads. There is no such thing as a free lunch though and a battery capable of a higher C rate will be heavier than a battery capable of a lower C rate, so you can either have more capacity for the same weight or a lighter boat with lower C cells.

Like pretty much everything in FE boating, it is a compromise and for every positive there will be a negative. What is the best battery for me won't necessarily be the best battery for you, hell the best battery for me varies from boat to boat, or even with the same boat depending on how i want to run it. There is no best battery, just a best battery for your individual use case.

What doesn't make a real difference except to your wallet is marketing BS, and there is a LOT of that going on with LiPo C rates and while MaxAmps "150C" actually being 15C and Spectrum "100C" actually being 30C are some of the worst offenders given their premium price, it is certainly not limited to them, SMC distribute some of the best LiPo batteries available, including their "150C" being the the highest discharge rate battery you can buy today, but this pinnacle of current high C rate battery technology is still only an actual 55C. I know of zero RC LiPo distributers that put accurate C rates on their labels, so only testing can sort the wheat from the chaff and RCgroups is probably the best place to find those tests.

Having said that, while they are all lying to us about their C rate, generally within each distributor's range the higher the C rate on the label, the higher the actual C rate. So you can be fairly confident that the SMC 135C will be more capable of high C rates than SMC 120C, and Turnigy Panther 70C will be more capable at high C rates than Turnigy Panther 40C, just not necessarily that SMC 120C will be more capable than Panther 70C.

While SMC 150C are capable of the highest real C rate, if you are not currently trying to pull more current than your SMC 120C and 135C can supply, that part of the equation is moot, but the lower internal resistance it has to get that higher C rate will give you a higher voltage under heavy loads and thus more RPM to the prop, but they are also heavier which will increase your boat's drag, there are a myriad of boat and driving factors that may make it a positive or negative overall change, or no change at all, and if there is a change i have no idea if you are racing/timing/logging close enough to notice it either way. In the past I have switched from a real 15C to a real 40C battery which allowed me to prop up further and gain nearly 10mph in SAWs, but trying to use that same battery in a Naviga race cost me 2 laps in a 6 minute race as the weight effected the cornering which far overcame the few extra RPM under a lesser load that I got when I wasn't propped up.

[Doby]

Take all Mfr's "C Ratings" with a major grain of salt.

[fweasel]

Yes C rate makes a difference a battery capable of a higher C rate will have a lower internal resistance, thus will run cooler for a given load and will sustain higher voltages under higher loads. There is no such thing as a free lunch though and a battery capable of a higher C rate will be heavier than a battery capable of a lower C rate, so you can either have more capacity for the same weight or a lighter boat with lower C cells.

Like pretty much everything in FE boating, it is a compromise and for every positive there will be a negative. What is the best battery for me won't necessarily be the best battery for you, hell the best battery for me varies from boat to boat, or even with the same boat depending on how i want to run it. There is no best battery, just a best battery for your individual use case.

What doesn't make a real difference except to your wallet is marketing BS, and there is a LOT of that going on with LiPo C rates and while MaxAmps "150C" actually being 15C and Spectrum "100C" actually being 30C are some of the worst offenders given their premium price, it is certainly not limited to them, SMC distribute some of the best LiPo batteries available, including their "150C" being the the highest discharge rate battery you can buy today, but this pinnacle of current high C rate battery technology is still only an actual 55C. I know of zero RC LiPo distributers that put accurate C rates on their labels, so only testing can sort the wheat from the chaff and RCgroups is probably the best place to find those tests.

Having said that, while they are all lying to us about their C rate, generally within each distributor's range the higher the C rate on the label, the higher the actual C rate. So you can be fairly confident that the SMC 135C will be more capable of high C rates than SMC 120C, and Turnigy Panther 70C will be more capable at high C rates than Turnigy Panther 40C, just not necessarily that SMC 120C will be more capable than Panther 70C.

While SMC 150C are capable of the highest real C rate, if you are not currently trying to pull more current than your SMC 120C and 135C can supply, that part of the equation is moot, but the lower internal resistance it has to get that higher C rate will give you a higher voltage under heavy loads and thus more RPM to the prop, but they are also heavier which will increase your boat's drag, there are a myriad of boat and driving factors that may make it a positive or negative overall change, or no change at all, and if there is a change i have no idea if you are racing/timing/logging close enough to notice it either way. In the past I have switched from a real 15C to a real 40C battery which allowed me to prop up further and gain nearly 10mph in SAWs, but trying to use that same battery in a Naviga race cost me 2 laps in a 6 minute race as the weight effected the cornering which far overcame the few extra RPM under a lesser load that I got when I wasn't propped up.

Mic drop...

[tbonemcniel]

Yes C rate makes a difference a battery capable of a higher C rate will have a lower internal resistance, thus will run cooler for a given load and will sustain higher voltages under higher loads. There is no such thing as a free lunch though and a battery capable of a higher C rate will be heavier than a battery capable of a lower C rate, so you can either have more capacity for the same weight or a lighter boat with lower C cells.

Like pretty much everything in FE boating, it is a compromise and for every positive there will be a negative. What is the best battery for me won't necessarily be the best battery for you, hell the best battery for me varies from boat to boat, or even with the same boat depending on how i want to run it. There is no best battery, just a best battery for your individual use case.

What doesn't make a real difference except to your wallet is marketing BS, and there is a LOT of that going on with LiPo C rates and while MaxAmps "150C" actually being 15C and Spectrum "100C" actually being 30C are some of the worst offenders given their premium price, it is certainly not limited to them, SMC distribute some of the best LiPo batteries available, including their "150C" being the the highest discharge rate battery you can buy today, but this pinnacle of current high C rate battery technology is still only an actual 55C. I know of zero RC LiPo distributers that put accurate C rates on their labels, so only testing can sort the wheat from the chaff and RCgroups is probably the best place to find those tests.

Having said that, while they are all lying to us about their C rate, generally within each distributor's range the higher the C rate on the label, the higher the actual C rate. So you can be fairly confident that the SMC 135C will be more capable of high C rates than SMC 120C, and Turnigy Panther 70C will be more capable at high C rates than Turnigy Panther 40C, just not necessarily that SMC 120C will be more capable than Panther 70C.

While SMC 150C are capable of the highest real C rate, if you are not currently trying to pull more current than your SMC 120C and 135C can supply, that part of the equation is moot, but the lower internal resistance it has to get that higher C rate will give you a higher voltage under heavy loads and thus more RPM to the prop, but they are also heavier which will increase your boat's drag, there are a myriad of boat and driving factors that may make it a positive or negative overall change, or no change at all, and if there is a change i have no idea if you are racing/timing/logging close enough to notice it either way. In the past I have switched from a real 15C to a real 40C battery which allowed me to prop up further and gain nearly 10mph in SAWs, but trying to use that same battery in a Naviga race cost me 2 laps in a 6 minute race as the weight effected the cornering which far overcame the few extra RPM under a lesser load that I got when I wasn't propped up.

Well said