Re: OT My simple electric bike

Took it out in sunny afternoon 98°F weather for a 6 mile trip. The 20V

>5AH battery shows one out of three bars remaining. Drill got hot but >there was no performance change.

This is really interesting, but I'm having trouble with some of the numbers. Say the "two bars" consumption equals, roughly, 3 A-hr. At 20 volts, we have 60 W-hr. Just guessing here, but say you travelled that

6 miles at 12 mph.

That means the drill was drawing an average of 120 W for a half-hour. Let's be generous and say that the system efficiency is 80% from storage to power at the drill shaft. So, given chain and friction losses at the tire, you have 1/8 hp driving the bike.

Will that be enough to move you at 12 mph? I'm not familiar with the actual power consumed by these bikes, but that sounds low. Am I missing something?

Reply to
Ed Huntress
Loading thread data ...

Well consider also that the bars may not be an accurate indicator of the state of charge.

Reply to
Leon

I looked up some energy research data on bicycles and it looks like you can get just about 12 mph with 100 - 120W. So you're right in there.

Reply to
Ed Huntress

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.