Pennzoil Q&A

Click here to participate in the Pennzoil Q&A

Recent Topics
New and Blocked
by ChristianReske
17 minutes 42 seconds ago
topping off edge gold with edge black
by meborder
34 minutes 33 seconds ago
Synthetic oils in Germany
by toyota62
44 minutes 58 seconds ago
way to many donuts
by CourierDriver
46 minutes 4 seconds ago
Prestone All Makes vs. Prestone Dexcool Antifreeze
by Lillikai
55 minutes 8 seconds ago
Old Car Quiz
by Charlie1935
Today at 07:00 AM
Load & Inflation Tables
by inquirer
Today at 06:41 AM
wrong diagnosis
by bowlofturtle
Today at 06:05 AM
Kia optima tires
by Grambo
Today at 06:04 AM
Corvette UA0 with Redline 5w30: High Lead
by Dirty_Howie
Today at 12:45 AM
Pure one cut no tears PL10241
by Skanky
Yesterday at 11:16 PM
Virgin filters cut open-Federated,BWD Niehoff,Serv
by ChevyBadger
Yesterday at 11:10 PM
Newest Members
help_please, Mr_EMan, Firas, ChristianReske, nash3222
55262 Registered Users
Who's Online
77 registered (Al, adamrc, 2009Edge, 3800Series, Astro_Guy, andyd, 7 invisible), 1450 Guests and 75 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
55262 Members
66 Forums
236965 Topics
3819324 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Page 2 of 2 < 1 2
Topic Options
#3316444 - 03/19/14 12:58 AM Re: Battery completely dead ... but at 9V? [Re: Miller88]
MNgopher Offline

Registered: 09/17/02
Posts: 3262
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.

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

Registered: 08/18/04
Posts: 2711
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

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

Registered: 07/22/05
Posts: 9603
Loc: NorthEast
I think the guys who did that want your NEW battery!

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

Registered: 10/15/10
Posts: 1252
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

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

Registered: 04/09/08
Posts: 9181
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.
'00 Jeep Cherokee
'11 Ford Focus

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

Registered: 06/09/12
Posts: 303
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.

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

Registered: 04/09/08
Posts: 9181
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.
'00 Jeep Cherokee
'11 Ford Focus

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

Registered: 12/27/05
Posts: 576
Loc: Chicago
Here is one from Associated Equipment that will recharge a battery down as low as 1v. Thats the override switch.

This Interacter will charge also as low as 1v.

Both made in the USA.

Page 2 of 2 < 1 2