It shouldn't need to help on a long hill - if your not at partial throttle and you are geared right.
Using info from the other post (LI), it's a 26" bike with a 1.978" diameter + grip motor, call it 2" so total physical reduction is 13:1
For comparison 20mph on 26" would require wheel RPM of 258.5
Running on 8S (as he was) hot would be roughly (assuming 4.1v per cell initially on first load) 32.8/33v, for this argument let's say it's only 32v.
The motor in question was an eFlite Power 110 - rated for 16 lb models maximum and up to 2000w with a kV of 295, Max Burst Current of 65A for 15 seconds and continuous max of 55A.
First how fast was the motor spinning?
According to poster, I think he reached 58 mph no load speed driving the wheel off ground... some quick math:
749.53846153846153846153846153846 RPM / 336 * 13 = 9744
No efficiency information about that motor but I think we can assume 85% without being too far off mark.
Now, let's do the math the proper way...
295 * 32 = 9440 RPM
Wow... that's not bad, very close to on mark: 9440 by the math and 9744 with the wheel up and likely a few amp load so no voltage sag of the 8S pack from full charged.
There in lies the problem.
Assuming a top speed of 49.3 MPH (85% of 58mph) means to acheive anything but about 48mph at nominal voltage would require partial throttle. This is one reason I'm so big on gearing motor output through multiple ratios.
A better fit for that given setup would have been 35mph @ nominal voltage which we would figure out by:
35 MPH * 336 = 11760 / 26" = 452.31 RPM
295 kv * .85 (factor efficiency under load) = 250.75 loaded kV
452.31 * 13 (multiply target RPM by reduction ratio) = 5880.03 RPM Required @ motor (load accounted for)
5880.03 / 250.75 = 23.45v nominal is perfect
23.45 / 3.7 = 6.3 S Lipo
So for this setup 6S would have been perfect and would give a nominal speed of approx 35mph.
It's important to note, were talking about a delta wound motor and a difference of RPM at the shaft of roughly 3600 RPM or 21.42 MPH difference between the failure scenario and this calculated scenario.
Also... 2000w is the rated power so at 22.2v we could provide 90A maximum with the 6S, on a full charge that would drop to 80A (assuming 24.96 for 6S fully charged).
And I am not sure if the CC ICE or the other logger are more accurate - honestly for peak capture, the sample rate needs to be pretty darn high - spikes like that (factor of difference, not really that level) I only see with my EagleTree logger setup to the Highest Sample rate which gives me about 8 - 10 minutes maximum of logging (as opposed to 20 hours at 2 samples per second)... I would tend to believe the higher number of Amps.
In either case just 100A surge at full charge 8S would be > 3kw, 33% more than the motor is rated for at it's maximum
Add to all the above - the attempted partial throttle uphill, overgeared by 20mph and
BTW: If that motor can handle a 16lb model, then with a 13:1 reduction the max load (in theory) should be 208 lbs - LI is about 165 + bike + bits so probably right in that range.
Anyone as always, feel free to correct, clarify or otherwise make sense of my ramblings