Originally Posted by AdrianM
Yup but what does that really mean? Are the 7.2v nominal 1400SCR packs that I ran in 1985 really the same as the 7.2v nominal IB3800's today....nope.
In the grand scheme of things the 0.2v increase is insignificant. The really big deal is how much lower the IR of the LiPo's are and how much more capacity they have.
Adrian - So 200mv (0.2 volts) are insignificant...
I am glad to hear that because there are people in this industry that claim that 0.005v (5 millivolts) make a difference and sell battery packs rated by VOLTAGE NUMBERS.
THANKS FOR PROVING THIS as AXXIS RACING has been saying this all along.
VOLTAGE IS INSIGNIFICANT... POWER DEFINES A BATTERY. (IR,TRANSIENT RESPONSE, and other values define a GREAT battery, not a few millivolts)
There are many factors that make a battery PERFORM, and numbers alone do not dictate that. Anyone that is an experienced engineer that does ongoing battery research knows that. Testing batteries under different parameters as Axxis Racing does helps us find the best performing batteries. The industry standard equipment used to test and match batteries can not perform ANY OF THESE TESTS.
I am not saying thatthey are doing the WRONG things, I just say that there are much better ways to test, enhance, and match batteries.
I have been saying that all along (over 18 years...the voltage issue). Yet, the INDUSTRY keeps matching batteries by voltage and charging much more for an extra millivolt. (A 1.199 v a 1.200) Yet, you can have cellswith LOWER Vavg that will perform much better, yet people ignore them and go for the one with the highest voltage...even if its 1 mv.
Like you said, IT IS INSIGNIFICANT... and you are talking about 200mv (0.200) not just a few millivolts
and you are CORRECT!
ALL motors have a Kv constant, right?
So what does that mean? Well, if you have a motor with a Kv of 3.5 (3500 RPM/volt) like a typical stock motor, that motor will turn 4095 (NO LOAD) rpms at 1.170 volts and 4200 rpms at 1.200...a difference of 30 millivolts (0.030volts) and a total NO LOAD RPM INCREASE OF ONLY 105 rpms. That is INSIGNIFICANT because once that motor is under load, you will nort notice ant difference whatsoever.
People have jumped at me when I have said that millivolts are insignificant, and I have been told that I do not know what I am talking about and that I use NON STANDARD equipment to test and match batteries. Yet, the Axxis IB3800 VoltaXX HES Enhanced batteries are proving themselves at tracks all over the country (and Internationally).
Anyway, THANKS FOR CLEARING THIS ISSUE.
I have been waiting from someone in the industry to tell the truth
I know this thread is about the LiPo's, but I hasd to take the opportunity to reply to the voltage (or MINI VOLTAGE) issue.
LiPo's will also change the way we test and match, because you have to perform different tests to find the best LiPo's from any given batch. Vavg and runningtime alone WILL not work as well as other test procedures.
...and regarding motor temperature, Rick is correct, as long as the load does not increase there is no real reason for the temperature to increase.
However, if the operating temperature reaches a critical point because of poor gearing, long runs will overheat the motors as the IR (of the motor) will continue to increase, then temperature...and you end up getting into an infinite loop.