Go Back   EcoModder Forum > EcoModding > Instrumentation
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 11-24-2012, 10:39 PM   #1 (permalink)
Master EcoModder
 
ever_green's Avatar
 
Join Date: May 2011
Location: Toronto
Posts: 264

gueff - '19 Mercedes Benz A250 4MATIC AMG
90 day: 30.55 mpg (US)
Thanks: 8
Thanked 79 Times in 33 Posts
SG2 battery voltage

i was wondering how accurate the battery voltage number by scangauge is? when my car has been out overnight in near freezing tempratures the voltage is 11.8v off and 14.7v idle. does this mean my battery is done? the car does turn over slightly lazily when weather is cold, but when its warm it starts like a champ.

__________________
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 11-25-2012, 09:20 AM   #2 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,203

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

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

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)

Daox's Volt - '13 Chevrolet Volt
Thanks: 2,501
Thanked 2,585 Times in 1,553 Posts
Double check the voltage with a voltmeter of some sort. That will tell you. From my experience, I think my SG was .1V off (if it was even that much). Its fairly accurate IMO.
__________________
Current project: A better alternator delete
  Reply With Quote
Old 11-25-2012, 10:59 AM   #3 (permalink)
Southern Squidbillie
 
Join Date: Aug 2012
Location: Heart of Dixie
Posts: 97
Thanks: 50
Thanked 26 Times in 22 Posts
Yes that battery is toast

Quote:
Originally Posted by ever_green View Post
when my car has been out overnight in near freezing tempratures the voltage is 11.8v off and 14.7v idle. does this mean my battery is done? the car does turn over slightly lazily when weather is cold, but when its warm it starts like a champ.
Be ready to replace it at any minute, you are on borrowed time at 11.8 volts.
  Reply With Quote
Old 11-25-2012, 12:47 PM   #4 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,190
Thanks: 179
Thanked 1,525 Times in 1,126 Posts
...something else to remember, each "bolted-junction" in an electrical path can (worse-case) have a "voltage-drop" of 0.1VDC! So also check ANY connections that are "bolted" together (ie: clamps onto battery, terminal-to-teminal junction, etc.) for tightness.
  Reply With Quote
Old 11-25-2012, 03:14 PM   #5 (permalink)
Master EcoModder
 
ever_green's Avatar
 
Join Date: May 2011
Location: Toronto
Posts: 264

gueff - '19 Mercedes Benz A250 4MATIC AMG
90 day: 30.55 mpg (US)
Thanks: 8
Thanked 79 Times in 33 Posts
ok i checked all connections and they all seemed to be tight. there is a bit of black grease on the clamps though. i also drove thr car on the highway at about 2500 rpm for an hour without any accessories on. i have lots of accessories including an aftermarket 600w amplifier. then when i got home i took readings and it read 12.7v car off and 14.3v on. so i think my battery was just low on charge. now my only concern is discharge rate. i will be checking the voltage again tuesday to see if it can hold up in ~30'f temprature.
__________________

Last edited by ever_green; 11-25-2012 at 03:29 PM..
  Reply With Quote
Old 11-25-2012, 10:45 PM   #6 (permalink)
halos.com
 
Join Date: Oct 2009
Location: Oklahoma City, OK
Posts: 528

ECONORAM - '07 Dodge RAM 1500 QC SLT flex-fuel
90 day: 18.16 mpg (US)

the Avenger - '08 Dodge Avenger SXT
90 day: 27.06 mpg (US)
Thanks: 385
Thanked 94 Times in 80 Posts
Send a message via Yahoo to ECONORAM
Have you checked the fluid levels in the battery? Every battery I've owned has needed fluid at some time. One item I like to add is VX-6 battery additive. Seems to keep them working longer. Amazon.com: Charge-It Concentrated Battery Additive: Automotive
  Reply With Quote
Old 11-26-2012, 12:33 AM   #7 (permalink)
Master EcoModder
 
ever_green's Avatar
 
Join Date: May 2011
Location: Toronto
Posts: 264

gueff - '19 Mercedes Benz A250 4MATIC AMG
90 day: 30.55 mpg (US)
Thanks: 8
Thanked 79 Times in 33 Posts
nope i havent used battery additives for a decade since car batteries are sealed now. plus i was told that all they do is clean the lead surface of sulfates and they do Not return the active material for charging.
__________________
  Reply With Quote
Old 11-26-2012, 01:18 PM   #8 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
My ScanGauge typically reads 0.1 - 0.2 volts low compared to a voltmeter reading at the battery itself.

You say you checked the voltage via the ScanGauge with the car "off". But was the ignition turned to "on" or "accessory"? If so, that will drop battery voltage some (compared to not having the ignition key in).

You can check voltage via the SG without the ignition key by waking it up -- pressing a button -- and calling up voltage gauge.
__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



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 11-26-2012, 01:36 PM   #9 (permalink)
Master EcoModder
 
ever_green's Avatar
 
Join Date: May 2011
Location: Toronto
Posts: 264

gueff - '19 Mercedes Benz A250 4MATIC AMG
90 day: 30.55 mpg (US)
Thanks: 8
Thanked 79 Times in 33 Posts
my first check with 11.8v was with key in acc. my second check after driving the car with no acc on was 12.7v while car was off with no key in ignition. i just chwck the voltage after it being off for 24hrs in freezing temps and voltage is 12.4-12.5v car off.
__________________
  Reply With Quote
Old 11-26-2012, 01:38 PM   #10 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
In these temps, 12.4-12.5 via the SG with no ignition key is fine.

__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



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
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com