e-bike update - Fuel Economy, Hypermiling, EcoModding News and Forum

Lazarus · 03-22-2008, 07:35 PM

Just wanted to give an update. I purchased a conversion kit to turn my road bike into an electric bike. I've put a little over 500 miles on it and it still performing great. Batteries are holding up nicely. I've put a little over 60 cycles on them and charge the 36 volt (SLA) system after every ride no matter how short. I use the motor as an assist to decrease my commute times so I'm always helping.

The longest commute without recharge has been 36 miles and the recharge time was 4.5 hours with a 45 watt/hour re-charge. Anything under 10 miles is usually done in around 1-1.5 hours and trips in the 20 mile range are 2.5-3.00 hours. There is a noticeable difference in performance when cold. It will be interesting to see how they hold up in a month or so when we start getting the 90-100 degree temps. Pic on the set up can be found here.

friedlbug · 03-22-2008, 08:59 PM

Great update and log. Thanks.

AndrewJ · 03-22-2008, 09:23 PM

What kind of speeds do you normally keep up in the flats (with and without electric assist)?

Lazarus · 03-22-2008, 11:52 PM

Quote:

Originally Posted by AndrewJ

What kind of speeds do you normally keep up in the flats (with and without electric assist)?

I really don't know because of the way I use it and the terrain. I have rolling terrain to deal with. Without probably about 16-17 mph. With about 20 mph. The Flat out speed has gotten better since I first tested it. With the motor only it tops out about 23 mph.

Since my commutes are pretty long I hypermile the pack and just use the motor to keep the speed up around 20 mph. It's on and off quite a bit to save the pack. I use a pluse and glide to keep the average around 19-20 over my commute.

AndrewJ · 03-23-2008, 01:05 AM

Quote:

Originally Posted by Lazarus

I really don't know because of the way I use it....I hypermile the pack...

Hypermiling dies hard doesn't it.

MetroMPG · 03-23-2008, 10:46 AM

Nice update.

Your batteries are used, from an alarm company, yes? Can/do you monitor voltage under load?

Lazarus · 03-23-2008, 12:00 PM

Quote:

Originally Posted by MetroMPG

Nice update.

Your batteries are used, from an alarm company, yes? Can/do you monitor voltage under load?

No these are the originals that came with the conversion kit. I have a couple of alarm batteries that I'm trickle charging every now and again sitting waiting for action. I was thinking of going to a 48V system to get a little more speed but have not had the time to mess with it.

I have a small DVM hooked to the handle bars. There is not much pull down WTO but then again I only engage once I'm up to speed. Even on hills I have not seen lower then 37V. I have a brushless motor maybe that's why.

Otto · 03-24-2008, 01:51 AM

Can the batteries easily be removed from the bike?

If so and not too heavy, you could take them into the house/office where it's warmer, maintaining better power.

BTW, what kind of batteries?

Otto · 03-24-2008, 01:54 AM

Nother question: How much power does this setup make, compared to the output of a really good cyclist?

I'm really asking how well this propulsion system might do on a streamliner fairing. Your thoughts and insights appreciated.

MetroMPG · 03-24-2008, 09:36 AM

Otto - that's a really good suggestion about keeping the batteries warm.

EV builders who live in cold winter climates often insulate, or insulate plus heat their batteries to avoid the winter effects of cold temperatures on battery chemistry.

Batteries don't do well in very high heat either - in the peak summer temps, it might also make sense to bring them inside, if the building is air conditioned.