Go Back   EcoModder Forum > EcoModding > Fossil Fuel Free
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 10-21-2008, 12:55 PM   #731 (permalink)
EV test pilot
 
bennelson's Avatar
 
Join Date: Jan 2008
Location: Oconomowoc, WI, USA
Posts: 4,356

Electric Cycle - '81 Kawasaki KZ440
90 day: 334.6 mpg (US)

S10 - '95 Chevy S10
90 day: 30.48 mpg (US)

Electro-Metro - '96 Ben Nelson's "Electro-Metro"
90 day: 129.81 mpg (US)

The Wife's Car - Plug-in Prius - '04 Toyota Prius
90 day: 78.16 mpg (US)
Thanks: 12
Thanked 551 Times in 332 Posts
Almost 40 miles!

You would SMOKE my Electro-Metro with your 48v slow-n-steady battery pack in the range department!

I gotta replace that one battery...

__________________


300mpg.org Learn how to BUILD YOUR OWN ELECTRIC CAR CHEAP
My YouTube Videos
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 10-21-2008, 01:59 PM   #732 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 19,652

Blackfly - '98 Geo Metro
Team Metro
90 day: 70.72 mpg (US)

ForkenSwift - '92 Geo Metro EV
Last 3: 95.68 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 47.99 mpg (US)
Thanks: 2,136
Thanked 4,895 Times in 2,460 Posts
Yeah, but how worn out are your batteries? Could just plug in your numbers to my calcs.
__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 10-21-2008, 03:54 PM   #733 (permalink)
Losing the MISinformation
 
Intrigued's Avatar
 
Join Date: Oct 2008
Location: Southern Missouri
Posts: 393

Quad Cam - '00 Oldsmobile Intrigue GX
Last 3: 25.94 mpg (US)
Thanks: 15
Thanked 3 Times in 3 Posts
72v vs. 48v

Now, that brings up a question that I may have seen before: with exactly the same type of battery, in exactly the same type of car, (bear with me ) and driving at the same approximate amperage, the 72 volt system will go faster, because of the extra voltage, but will have approximately the same range? Or...would that be 8 9v batteries vs. 8 6v batteries makes it even...

...or was that just a little too much to ask...

Intrigued...for real...
__________________


The brake pedal is my enemy. The brake pedal is my enemy. The brake pedal...
  Reply With Quote
Old 10-21-2008, 04:03 PM   #734 (permalink)
EV test pilot
 
bennelson's Avatar
 
Join Date: Jan 2008
Location: Oconomowoc, WI, USA
Posts: 4,356

Electric Cycle - '81 Kawasaki KZ440
90 day: 334.6 mpg (US)

S10 - '95 Chevy S10
90 day: 30.48 mpg (US)

Electro-Metro - '96 Ben Nelson's "Electro-Metro"
90 day: 129.81 mpg (US)

The Wife's Car - Plug-in Prius - '04 Toyota Prius
90 day: 78.16 mpg (US)
Thanks: 12
Thanked 551 Times in 332 Posts
The general consensus is that higher voltage systems are better.

Higher voltage = less amperage at the same amount of work power (watts)

Batteries are more efficient when drawing fewer amps. If you draw only half the amperage, you can get MORE than double the total amount of amps out of them.

6v batteries have an advantage over typical 12v in that they have beefier construction and are better designed in general to deeply discharge.

A popular way of constructing an electric vehicle right now is to fill up a pickup truck with enough 6V batteries (good price and deep cycling) run in series for a high voltage, say, 144V to have good speed and efficiency.

Needless to say, that's far too much weight for a mere Metro. Also, buying that many batteries new costs more than I spent for my entire conversion budget!

Come to think of it, that size battery pack weighs more than a Metro!
__________________


300mpg.org Learn how to BUILD YOUR OWN ELECTRIC CAR CHEAP
My YouTube Videos
  Reply With Quote
Old 10-21-2008, 06:17 PM   #735 (permalink)
Losing the MISinformation
 
Intrigued's Avatar
 
Join Date: Oct 2008
Location: Southern Missouri
Posts: 393

Quad Cam - '00 Oldsmobile Intrigue GX
Last 3: 25.94 mpg (US)
Thanks: 15
Thanked 3 Times in 3 Posts
"Come to think of it, that size battery pack weighs more than a Metro!"

Yeah, 24 batteries would TAKE a pickup truck to hold them. Weight and Space both... No rapid-change videos there!

They didn't teach us anything like that at the GM tech schools back in the '80s. I bet there are classes now for the hybrids and the Volt.

What I need to do is get a better grip on range per battery. I start missing on a cylinder or two when I try to understand range as a function of series vs. parallel connections...and how voltage figures in...

still Intrigued...
__________________


The brake pedal is my enemy. The brake pedal is my enemy. The brake pedal...
  Reply With Quote
Old 10-22-2008, 12:23 PM   #736 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 19,652

Blackfly - '98 Geo Metro
Team Metro
90 day: 70.72 mpg (US)

ForkenSwift - '92 Geo Metro EV
Last 3: 95.68 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 47.99 mpg (US)
Thanks: 2,136
Thanked 4,895 Times in 2,460 Posts
Why not increase the pack voltage?

(Several people have asked whether there's any plan to upgrade the pack voltage, since we're about to come into a pile of what may be decent used batteries.

Of course looking at Pauls & Ben's 72v conversions, I have some envy issues.

But I think the car will stay at 48v. Why?
  1. The car's performance is adequate for its intended use. In a year of driving it, I've never been honked at or sent anyone into a purple rage - but I'm careful to choose routes (and/or travel times) where I'm not going to hold up the traffic flow because of the car's slow acceleration or power (hills).
  2. A new controller would be required.
  3. A new/additional charger would be required.
  4. A new DC-DC converter would be required.
  5. I'd have to make more LED battery bargraph monitors.
  6. The car is already close to the limit of GVWR. 72 volts would put it at or over, and also require a pack layout that would shift the F/R balance further to the back, requiring stronger rear springs, possibly losing the rear seat, and potentially hurting front tire traction in slippery conditions.
e-Turbo, maybe...

That said, I am still intrigued with the idea of adding a better 12v accessory battery (perhaps AGM), and planning a controller bypass circuit that would also switch that battery in series with the pack - a direct 60v motor connection for occasional faster acceleration, when wanted. Turbo boost.

I've toyed with this idea for some time (It's buried somewhere in this thread), but never pursued it because the car is passable on 48v (get it!? ). If I were to do it, it would just be for fun - for the technical exercise.
__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 10-22-2008, 02:04 PM   #737 (permalink)
EV test pilot
 
bennelson's Avatar
 
Join Date: Jan 2008
Location: Oconomowoc, WI, USA
Posts: 4,356

Electric Cycle - '81 Kawasaki KZ440
90 day: 334.6 mpg (US)

S10 - '95 Chevy S10
90 day: 30.48 mpg (US)

Electro-Metro - '96 Ben Nelson's "Electro-Metro"
90 day: 129.81 mpg (US)

The Wife's Car - Plug-in Prius - '04 Toyota Prius
90 day: 78.16 mpg (US)
Thanks: 12
Thanked 551 Times in 332 Posts
I completely agree with you, Darin.

The only decent way to upgrade pack voltage is if the new one will fit within the controller and dc/dc converter specs you already have.

For example, I was able to easily upgrade the motorcycle from 36 to 48 volts because I was using a 24-48V controller and a 36-72V Dc/DC converter.

The only thing I had to do was add one more battery and change a setting on the controller.
__________________


300mpg.org Learn how to BUILD YOUR OWN ELECTRIC CAR CHEAP
My YouTube Videos
  Reply With Quote
Old 10-22-2008, 05:54 PM   #738 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 19,652

Blackfly - '98 Geo Metro
Team Metro
90 day: 70.72 mpg (US)

ForkenSwift - '92 Geo Metro EV
Last 3: 95.68 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 47.99 mpg (US)
Thanks: 2,136
Thanked 4,895 Times in 2,460 Posts
speaking of DC-DC...



We've got two DC-DC converters. Both are the same module, but one's a bare bones unit and the other has a circuit board with some other bits on it to make it work better and last longer. Lee Hart suggested the one with the bits on it.

Anyway, we've never used either. We've just been trickle charging the 12v battery occasionally. Don't tend to run it down because we don't use the car much @ night.

But I'm taking a night course (intro to telescope astronomy), and don't want to kill the battery on the way to & from the college tonight, so I hooked up the "better" DC-DC this afternoon.

Someone on the EVDL said: "I used to test these modules at GE, they can take a beating." I can vouch for this because I hooked it up wrong the first try (mixed up the input/output wires) which caused a big spark.

Fortunately, the smoke stayed in. Double checked the wiring on the schematic, and now I've got 48v in and 14.5v out (no load), 100 watts max. Barely enough power to run the headlights, but it's enough to keep from killing the accessory battery anyway.
__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 10-22-2008, 06:12 PM   #739 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 10,294

CM400E - '81 Honda CM400E
90 day: 39.62 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's 04 Civic - '04 Honda Civic DX
90 day: 44.54 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)
Thanks: 1,812
Thanked 2,001 Times in 1,226 Posts
Don't turn your turn signals on! Does the converter have some sort of overdraw protection?
__________________
Current project: Heating the manual trans with engine coolant
  Reply With Quote
Old 10-22-2008, 06:48 PM   #740 (permalink)
EV test pilot
 
bennelson's Avatar
 
Join Date: Jan 2008
Location: Oconomowoc, WI, USA
Posts: 4,356

Electric Cycle - '81 Kawasaki KZ440
90 day: 334.6 mpg (US)

S10 - '95 Chevy S10
90 day: 30.48 mpg (US)

Electro-Metro - '96 Ben Nelson's "Electro-Metro"
90 day: 129.81 mpg (US)

The Wife's Car - Plug-in Prius - '04 Toyota Prius
90 day: 78.16 mpg (US)
Thanks: 12
Thanked 551 Times in 332 Posts
You might also want to slap a heatsink on the DC/DC.

I have a very small 100 watt converter on my motorycycle. Another EVer was shocked that I hadn't fried it yet. I think the fact that it's an open air vehicle has saved me so far.

That, and a motorcycle only has one headlight, but a Metro has two!

Run the DC/DC for a while with the heatlights on and feel how warm the thing gets.

How are you connecting the converter to the battery? What are you doing to power it up? (Turns on with key? etc.)

__________________


300mpg.org Learn how to BUILD YOUR OWN ELECTRIC CAR CHEAP
My YouTube Videos
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com