Electric 'pedicab' question

Recently, I happened to come upon an online advertisement for electric 'pedicab'. Two things bother me about what I read.

The vehicle is powered by a BLDC motor - why not a simple series wound DC motor that has a lot of starting torque, but none of the complexity of the BLDC motor controller.

The battery is Li-ion -- why not a simpler, far more rugged sealed lead acid battery whose charger is far simpler to design and implement.

Could there be any special reasons for the manufacturer's choice of motor type and battery ?

On Sun, 1 May 2016 22:53:38 -0700 (PDT), snipped-for-privacy@gmail.com Gave us:

They are using LiFePO4 batteries these days.

SLAs are so yesterday, and so heavy.

The only drawback of LiFePO4 is their price.

Lead acid is heavy. I don't know about the motor but if it's a pedla cab then maybe the starting torque is provided by pedal power.

George H.

Probably weight, power, and power to weight ratio.

A BLDC motor with rare-earth magnets will be smaller, lighter, and more efficient than any field-excited motor of the same general output capability.

LiPo batteries have similar advantages over lead-acid.

Whether, over the lifetime of the pedicab, this adds up to an overall advantage -- who knows?

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Tim Wescott 
Wescott Design Services 
http://www.wescottdesign.com

It looks like it's for the rich.

For the rest of us, sealed lead-acid batteries with series wound motors :D

Or simply walk :p

Michael

Precisely the point. More interesting is the fact that this advertisement is by a Taiwanese company.

Yes, it's not 1910 anymore. There have been advances in motors and batteries.

you can't do regenerative braking with a series motor. that'll reduce range.

same reason they don't use lead-acid for primary power in other electric automobiles, low energy/weight ratio.

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