Zero DS Upgraded for 2011

[alosix]

I will tell you on Monday :sombrero:

So.. did you figure this out.. or are you out of juice in the woods somewhere?

 

[Scott Brady]

It is the perfect round-town bike. I ride it almost daily and enjoy the ease of commute.

It would also be an ideal bumper mounted bike at 290 lbs. and could be charged from a big inverter on the camper. We used a big 1500 watt continuous sine wave and the Jeep's monster alternator.

Mike - it would be a wonderful first bike. Not even a clutch. . .

 

[alosix]

Nice

Any idea what issue of OJ might have some info on this trip?

 

[zimm]

neat commuter, but using the charging system of another vehicle is an extremely inefficient way of keeping a bumper bike "fueled", you dont get something for nothing.

 

[alosix]

neat commuter, but using the charging system of another vehicle is an extremely inefficient way of keeping a bumper bike "fueled", you dont get something for nothing.

No doubt, though I'd wonder how efficient it would end up being, given that at this point the bike is acting as a bit of a gas/electric hybrid. Charging while in motion should have the 'host' vehicle in an efficient power band and not likely take a noticeable amount of extra fuel. With any luck the OJ guys will have figured that all out for us.

I more like the weight of it for a bumper bike. I think its probably got enough range for what I'd do with with while out in the 725.

That's more of a secondary use though. I'm mostly looking for something low in maint to commute with.

 

[Scott Brady]

The impact to fuel economy by charging when driving would be negligible. However, at this point our evaluation is simply discovery. We have learned a lot so far.

The story should be in the summer issue.

 

[lowenbrau]

The impact to fuel economy by charging when driving would be negligible. However, at this point our evaluation is simply discovery. We have learned a lot so far.

The story should be in the summer issue.

I suspect it is more than negligible.

I estimate 1200W of charging for four hours to use a little less than a gal.

30 miles per gallon isn't nearly as impressive.

I still want one.

<edit> for the math lovers, some formulas.

Gasoline has 110,000 BTU/gal
Gassers use about 10,000 BTU/HP
Jeep gets about 30 MPG on the highway.
Jeep travels 60 MPH
Jeep uses 2 gal/h
Jeep needs 220000 BTU/H
Jeep needs 22 HP to travel down highway
Charger needs 1200W
746w= 1 HP
Charger uses 1.6 HP
22hp/1.6hp is 14%
14% of 8 gal is 1.12Gal

Nothing, including my math, is completely efficient so there is likely more to the story.
<end edit>

 

[nwoods]

Pretty sure my Jeep needs more than 22hp to travel down the highway....

 

[Scott Brady]

<edit> for the math lovers, some formulas.

Gasoline has 110,000 BTU/gal
Gassers use about 10,000 BTU/HP
Jeep gets about 30 MPG on the highway.
Jeep travels 60 MPH
Jeep uses 2 gal/h
Jeep needs 220000 BTU/H
Jeep needs 22 HP to travel down highway
Charger needs 1200W
746w= 1 HP
Charger uses 1.6 HP
22hp/1.6hp is 14%
14% of 8 gal is 1.12Gal
<end edit>

That is very useful. Thank you for that. The J8 gets closer to 22-24 mpg at the moment.

 

[lowenbrau]

Pretty sure my Jeep needs more than 22hp to travel down the highway....

If you can get 30 MPG @ 60 MPH , you are only using an average of 22 HP. It is surprising but if you run the numbers backwards, gasoline only has so many BTUs (110,000) If you are only burning 2 Gal/hour you are only making 22 HP

 

[lowenbrau]

Cool!

I found a calculator.

http://ecomodder.com/forum/tool-aero-rolling-resistance.php

 

[nwoods]

If you can get 30 MPG @ 60 MPH , you are only using an average of 22 HP. It is surprising but if you run the numbers backwards, gasoline only has so many BTUs (110,000) If you are only burning 2 Gal/hour you are only making 22 HP

Ah, I see! No, I do not get 30mpg. I might get 10mpg downhill with a tailwind.