Go Back   Honda-Tech > Honda and Acura Model-Specific Technical Forums > Honda Civic/Del Sol (1992 - 2000)
Sign in using an external account
Register Forgot Password?

Battery Pooched? Has 12.7V but wont start car

LinkBack Thread Tools Search this Thread
Old 05-08-2007, 10:00 AM   #1
W O T's Avatar
Join Date: Nov 2004
Posts: 1,713
iTrader Rating: (0)
Default Battery Pooched? Has 12.7V but wont start car

Came back from a weekend vacation to where I parked my car and the battery was dead. No power. Boosted it and drove home, when I got home (15min drive) I turned off the car and tried to turn it on to see if the battery was charged. No dice, didnt have enough juice to start the car.

Boosted it again and went for a high rpm rip on the highway, came back, and the battery was now fully juiced, car started hard no problems.

Left it overnight until today and I came out to a another dead battery, had power, but not enough.

So I throw the voltage tester on it and sure enough, 12.6-12.7V

Boosted it with a good battery then connected the dead battery and never turned the car off (just pulled off connections and connected dead batt)

Then I checked the voltage while running. 14.7VOLTS!!!! WTF!!

So whats going on here?

-its got 12.6V but wont star tthe car
-another battery with 12.5V starts it no problem
-alternator charging it good @ 14.7V

Batteries only a year old and I dont think I got the reciept anymore
W O T is offline   Reply With Quote
Old 05-08-2007, 10:03 AM   #2
Honda-Tech Member
Luserkid's Avatar
Join Date: Oct 2002
Location: Cali
Posts: 12,637
iTrader Rating: (0)
Send a message via AIM to Luserkid
Default Re: Battery Pooched? Has 12.7V but wont start car (W O T)

Sounds like something is draining your batt and draining it badly. Try jumping it and letting it idle for a while. Turn off the car and disconnect both power and neg. from the batt. and leave it for about 5 mins and then check the reading (do before you pull and after). If the reading changes then its a defaulty batt. If it stays the same then its something draining.


After the jump you read 14.7v, after the 5 mins you read 14v, batt. is good. If you come back and read 12v batt is bad.
Luserkid is offline   Reply With Quote
Old 05-08-2007, 10:12 AM   #3
Honda-Tech Member
Relic1's Avatar
Join Date: Oct 2002
Location: chicago burbs, Il, USA
Posts: 4,935
iTrader Rating: (0)

12V at the battery with no load is not necessarily a bad battery.typical automotive battery is 2.2V per cell, with 6 cells present. 13.2 at rest but every car has a little load on the battery at all times. (ECU memory, radio memory, etc) so a 12-12.6 rading is far from unreasonable.

the main thing is what does the voltage do when you start the car, or even switch on the lights. (ie apply load)
Flip the headlights on, initially the voltage will drop slightly then should hold around 12V, if it drops >~1V per 15-30 seconds after the voltage stabilizes, then it's time for a new battery.

bad battery, bad connections to battery, starter wire defective, bad starter... all of wihich will cause this problem.
and you're right, I can't spell.

the civic hatch community
Relic1 is offline   Reply With Quote
Old 05-08-2007, 10:17 AM   #4
W O T's Avatar
Join Date: Nov 2004
Posts: 1,713
iTrader Rating: (0)
Default Re: (Relic1)

Ya I figure 12.6V was good, I just dont get why it says the battery has that voltage but wont start the car

Then swap in a battery with the same voltage, and the car starts first kick

I'll check for parasitic loss later as Im at work now, I just dont get why the battery isnt keeping a charge or not using the charge that it has
W O T is offline   Reply With Quote
Old 05-08-2007, 10:36 AM   #5
Honda-Tech Member
Mashimaro's Avatar
Join Date: Apr 2003
Location: Vancouver, BC, Canada
Posts: 2,020
iTrader Rating: (1)

is it an Optima yellow top by any chance?

i had that measured 13volts, but when i connected it to a volt meter and touched it to a spare starter, the battery would actually drain down to 8volts output. it was fried, and i was choked cuz i thought my starter was dead and bought a new one...
Toda Power
Mashimaro is offline   Reply With Quote

Similar Threads
Thread Thread Starter Forum Replies Last Post
00 accord 4P alternator / resistance problem classified01 Honda Accord (1990 - 2002) 2 08-04-2014 09:28 PM
Need help with RSX Starter or Altenator? 94 IntegraLS Acura RSX DC5 & Honda Civic EP3 17 02-22-2012 07:45 AM
98 accord- dead battery, tach/speedo inop, wont charge dasjestyr@gmail.com Honda Accord (1990 - 2002) 4 02-11-2009 10:01 AM
2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disconected PINKS Honda Civic/Del Sol (1992 - 2000) 27 06-05-2006 05:57 PM
my optima battery just died wtf!!!!!!!!!! L. Honda Civic/Del Sol (1992 - 2000) 9 01-17-2005 10:22 PM

12, 127, 127v, 12v, battery, car, daed, dead, doesnt, power, reads, shows, start, volts, wont

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -8. The time now is 04:22 PM.

2014 Copyright, InternetBrands Inc.
Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.

Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for Honda-Tech.com content, comments, or advertising. Honda-Tech.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse Honda-Tech.com in any way. Copyright/trademark/sales mark infringements are not intended or implied.
Emails & Contact Details