circuit wrote:Since OP is using PMDC motor, it's efficiency is lower only like by 1-2%, when compared to BLDC alternatives used in ebikes.
I highly doubt that most BLDC motors in ebikes are as high an efficiency as something like Cedric Lynch's Agni, whcih though it is a brushed motor is still in the low-mid 90s of efficiency.
You can't really say that a brushed PMDC (or any other type) motor is less efficient just because it is PMDC or brushed (or whatever). If the BLDC (or other type) it's being compared to is not designed as well, it can certainly be a lot less efficient than a brushed PMDC (or other type) is.
If you want to give any realistic numbers for efficiency comparisons of motor types, you must also give an exact motor "brand", model, etc. for the comparison--just giving a type won't necessarily give a realistic comparison.
For example, the Agni 95 brushed motor is listed as 93% efficient on their main page for it, and charted at above 90% at the same voltage (36V) as the BLDC motor compared below this:
while this GoldenMotor BLDC motor is charted at less than 80% efficient even at it's peak:
http://www.goldenmotor.com/e-Bike-DIY/H ... 0Curve.pdf