Recent Topics
Oil at Walmart
by merdog
05/26/15 12:06 AM
MicroGard MGL57021 on 2007 Volvo XC70
by howie2092
05/25/15 11:07 PM
topping off with non-HDEO
by meborder
05/25/15 10:31 PM
Microgard MGL9018 unknown miles - yikes
by MoreCowbellAz
05/25/15 10:29 PM
Have any of you gone to see Fury Road?
by BRZED
05/25/15 09:58 PM
Finally Found Pennzoil Ultra at Walmart
by mike718
05/25/15 09:52 PM
Mopar or Other
by DarthDuty
05/25/15 09:35 PM
Another overfilling ATF question
by mclasser
05/25/15 09:05 PM
ATF for 1997 4l60E
by cdm1993
05/25/15 08:47 PM
Champ Oil Filters, Should I Buy This?
by s1mp13m4n
05/25/15 08:15 PM
Subaru fan not turning on.
by simple_gifts
05/25/15 08:12 PM
electric pool pump motor noisey
by raaizin
05/25/15 07:44 PM
Newest Members
Duc, Willroach, yanis, mattoutkast, TiredOfJunk
54103 Registered Users
Who's Online
39 registered (brslds, cdm1993, ClutchDisc, BusyLittleShop, 901Memphis, bdcardinal, 3 invisible), 823 Guests and 140 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
54103 Members
66 Forums
231869 Topics
3716566 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Page 1 of 2 1 2 >
Topic Options
#3316247 - 03/18/14 08:55 PM Battery completely dead ... but at 9V?
Miller88 Offline


Registered: 04/09/08
Posts: 8501
Loc: Onondaga County
Went out to my Cherokee today to try to continue playing around with the broken ujoint strap bolt.

I noticed my drivers side rear door was open. Battery was dead. The headlight switch was in the parking light position and interior lights were set to on.

So, obviously nothing happened.

I pulled the battery out and it still have 9V?

It's also having some issues taking a charge.

Shouldn't something at least happen with 9V? I'm wondering if the local lowlives also screwed up my electronics.

Top
#3316251 - 03/18/14 08:58 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
redbone3 Offline


Registered: 06/09/12
Posts: 277
Loc: Reno, NV
You are measuring 9V with no load. Measure the voltage under load and it is probably a whole lot lower. With the battery in the car, you can turn on the headlights and see a big drop in voltage.
_________________________
2014 Passat Wolfsburg, 1995 Miata.

Top
#3316254 - 03/18/14 09:01 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Miller88 Offline


Registered: 04/09/08
Posts: 8501
Loc: Onondaga County
Nothing happened with headlights turned on or cell phone charger plugged in.

No dome light either.

Top
#3316261 - 03/18/14 09:08 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Donald Offline


Registered: 03/21/04
Posts: 14926
Loc: Upstate NY
Some of these items may be controlled by relays that won't kick in at 9V.

Charge it with a plug-in charger than have it load tested. Check the cells for low battery acid level.

How old is the battery?

Some fancy chargers will not charge a very low voltage battery.
_________________________
2001 Jeep Grand Cherokee Laredo 4.0 - PP & M1
1999 Dodge Ram 2500 w/Cummins - Rotella T6 & M1
Amsoil ATF in both vehicles & Magnefine filter.

Top
#3316281 - 03/18/14 09:25 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
123Saab Offline


Registered: 10/27/10
Posts: 1349
Loc: PA
Dead cells can reduce the amps so it wont do much but still show some volts.

It's dead most likely.
_________________________
Twenty-twenty-twenty four hours to go I wanna be sedated
Nothin' to do and no where to go-o-oh I wanna be sedated

Top
#3316282 - 03/18/14 09:25 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
jeepman3071 Offline


Registered: 04/15/10
Posts: 2008
Loc: Storrs, Connecticut
Did you leave the door open or did someone force their way in?

Once the battery gets discharged enough, it can refuse to take a charge. Anything that low will result in weird things happening with the electronics. I had a dead cell in my battery, and all the gauges went crazy in my Jeep and it would run for 2 seconds and shut off. Chrysler electronic systems seem to be sensitive, and I think you might need a new battery. frown

How old is the battery?
_________________________
2000 Jeep Cherokee Sport 4.0L (152k) - PYB 10w30, Napa Silver 31516, Magnefine trans filter

Top
#3316285 - 03/18/14 09:29 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
morris Offline


Registered: 08/24/08
Posts: 3681
Loc: ks, wichita
i am not an electronics engineer. BUT i have learned that electronics chips if the needed voltage is not sent to them they CAN act very strangely. so if one just stops be glad.

Top
#3316290 - 03/18/14 09:33 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Chris142 Offline


Registered: 06/05/03
Posts: 12486
Loc: apple valley, ca
A 12v car battery is considered discharged at around 12.2volts. 9v is way dead.
_________________________
02 Wrangler durablend 10w40
87 F250 Diesel Mystic 15w50
04 Tahoe super-s 5w30
Z400 Lucas 10w30
KLR250 Maxima 10w40
Polaris Trailblazer delo 5w40

Top
#3316299 - 03/18/14 09:39 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Miller88 Offline


Registered: 04/09/08
Posts: 8501
Loc: Onondaga County
Battery is less than two years old.

I left it unlocked. That way the locals will just open it up and not break into it.

Top
#3316307 - 03/18/14 09:43 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
901Memphis Online   content


Registered: 08/14/10
Posts: 7643
Loc: Northern Kentucky
9v is extremely dead. Anything under 10.50v is basically flat. A fully charged battery with no charge or discharge for 6+ hours would be at least 12.60v or higher.

Get that battery charged before the damage gets worse, they don't like to go that low but it should recover fine. You may need a special charger to get it charged since it went so low. You can take it by an auto parts store for a quick charge or take this as an opportunity to buy a new charger.
_________________________
2002 Buick Century 108k - O'reilly HM 5w30/Fram Ultra XG 3980
Filter mag/Cooper CS5 GT/Wearever Platinum Ceramics
Triple Edge 4T65E/Maxlife Dex-Merc

Top
#3316314 - 03/18/14 09:49 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Miller88 Offline


Registered: 04/09/08
Posts: 8501
Loc: Onondaga County
Electrolyte levels are good and it didn't freeze.

Up to about 10.6 volts. I have it on the 2 amp charge. I try to avoid 6 amp charge.


Edited by Miller88 (03/18/14 09:49 PM)

Top
#3316335 - 03/18/14 10:02 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
JHZR2 Offline



Registered: 12/14/02
Posts: 35545
Loc: New Jersey
Classic shorted cell. No practical energy as the battery discharges into it, but yet open circuit reflects the chemistry on the other cells.

Top
#3316347 - 03/18/14 10:13 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Miller88 Offline


Registered: 04/09/08
Posts: 8501
Loc: Onondaga County
Likely put another battery into it frown

Nothing like a $500 month on vehicle repairs.

Top
#3316369 - 03/18/14 10:30 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Rolla07 Offline


Registered: 11/05/11
Posts: 2139
Loc: MTL, CANADA
Where do you live?!! My city its hit and runs!! Always something...
_________________________
2007 Corolla Red Pearl 125k miles
M1 EP 0w20 & TRD filter


Top
#3316414 - 03/18/14 11:36 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Barkleymut Offline


Registered: 01/27/04
Posts: 2655
Loc: Richmond, VA
Google tells me that he is very close to Syracuse NY
_________________________
09 Vue(95K) 2.4 4spd AT -PU 5w30 / 09 Flex(52K)3.5L PU / Moms car 04 Pilot(105K) 5w20 PP + Puro

Top
#3316444 - 03/19/14 12:58 AM Re: Battery completely dead ... but at 9V? [Re: Miller88]
MNgopher Offline


Registered: 09/17/02
Posts: 3186
Loc: Lakeville, MN
9V is way dead. Anything under 12V is pretty well dead, and you should be planning on buying a new battery. Our previous 88 Cherokee did the same thing. Left a door slightly open, lights on all night, and dead as a doornail. The battery limped on for two months, then kicked the bucket.

Top
#3316626 - 03/19/14 08:41 AM Re: Battery completely dead ... but at 9V? [Re: Miller88]
rshaw125 Offline


Registered: 08/18/04
Posts: 2661
Loc: Raleigh ,NC CSA
Put it on a 2 amp charge for a day. Remember the alternator is not designed to charge a dead battery. Drive it and then check voltage with engine off. Should be around 12.75 volts if fully charged.
_________________________
2012 Porsche Carrera S
1995 Plymouth Voyager

Top
#3316732 - 03/19/14 10:21 AM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Vikas Offline


Registered: 07/22/05
Posts: 9083
Loc: NorthEast
I think the guys who did that want your NEW battery!

Top
#3316810 - 03/19/14 11:08 AM Re: Battery completely dead ... but at 9V? [Re: rshaw125]
wrcsixeight Offline


Registered: 10/15/10
Posts: 1208
Loc: california
Originally Posted By: rshaw125
Put it on a 2 amp charge for a day.


The vehicle in question probably has a ~75 amp hour battery.

10.5 volts is considered 100% discharged. If the battery in question were still healthy, at still near full capacity when it was drain to 9v, it would require anywhere from 110 to 125% the energy removed from it. Lets say 125%

94 amp hours 94 amp hours divided by 2 amps is 47 hours.

If the charger used does not recognize the battery because of the 9v factor, the battery should be paralleled to a known good battery and then charged until its resting voltage is high enough that the charger will recognize it..

Since the battery in question is likely has nowhere near full capacity remaining, a day at 2 amps might be enough to bring it near full charge.

If this theoretical 2 amp charger does not raise the voltage into the mid 14's it is likely it will never
_________________________
LA 318 Roller Cam
M1 0w-30 AFE
FL-1A filter

Top
#3316937 - 03/19/14 12:21 PM Re: Battery completely dead ... but at 9V? [Re: Barkleymut]
Miller88 Offline


Registered: 04/09/08
Posts: 8501
Loc: Onondaga County
Originally Posted By: Barkleymut
Google tells me that he is very close to Syracuse NY


Yup. I live in the city of Syracuse. A mini detroit. Per capita, we have worse crime!

Anyway, I let it until the morning. Then let it sit for a while and checked voltage. 12.6.

That's higher than what it is after the Jeep sits for a few days. I have some parasitic draw that I need to get sorted out. It'll kill a battery on its own if left for 2 or 3 weeks.

I'm going to continue charging it. I'm sure I *could* have jumped it off of the Focus, but if it's that low, I don't want to risk the 14 year old alternator.

I'm going to let it charge at 2 amps overnight again and see what happens.

Top
#3317379 - 03/19/14 07:47 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
redbone3 Offline


Registered: 06/09/12
Posts: 277
Loc: Reno, NV
Originally Posted By: Miller88
Electrolyte levels are good and it didn't freeze.

Up to about 10.6 volts. I have it on the 2 amp charge. I try to avoid 6 amp charge.


6 amps won't hurt anything and it will charge faster.
_________________________
2014 Passat Wolfsburg, 1995 Miata.

Top
#3317801 - 03/20/14 07:55 AM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Miller88 Offline


Registered: 04/09/08
Posts: 8501
Loc: Onondaga County
Let it do the 6 amp charge for 6 hours last night. Getting there! It's holding voltage higher than it does in the Jeep. Hopefully letting it run again tonight on the 6 am charge I'll be fully charged.

Top
#3320160 - 03/22/14 07:49 PM Re: Battery completely dead ... but at 9V? [Re: Miller88]
Da Game Offline


Registered: 12/27/05
Posts: 574
Loc: Chicago
Here is one from Associated Equipment that will recharge a battery down as low as 1v. Thats the override switch.

http://associatedequip.com/product/model-9640/

This Interacter will charge also as low as 1v.

http://interacter.com/products/industrial-commercial-series-specs/

Both made in the USA.

Top
Page 1 of 2 1 2 >