Car battery stone cold dead (0.551VDC). Salvageable?

Thread Starter

Tonyr1084

Joined Sep 24, 2015
5,239
For two days the parking lights were left on unnoticed. This afternoon we went to start the car and nothing. ABSOLUTELY Nothing. Upon first test after having shut everything off and letting the battery rest for about an hour the read voltage was 551mV. As I said, stone cold dead.

It's an EverStart from Walmart - 5 year warranty; installed 5/17 (as the sticker on top says). It's on the charger now. Is charging it a waste of time or is there a chance it might come back?
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
5,239
At initial setup and turn-on of the charger (set to 40A @ 12V) the battery read 12.9V and quickly went up to 14.0V. Last check the voltage has dropped to 13.12V and is drawing 20A.
 

MisterBill2

Joined Jan 23, 2018
7,309
It may recover. I had a similar problem once, wife said she saw the lights on a week earlier and thought it was a reflection. Give it a whole day and if the charge current never drops below 5 amps it may be time for a new battery. But also, disconnect the charger and check tghe voltage and see if it drops off. And see if the car will start after sitting a day after charging. The proof is in the performance. Also check to see if the battery water is low.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
5,239
Started the car and put it in the garage. It's on the charger now. The charger has two settings: 10A and 40A. The 40A is for starting the car with a weak battery. After charging the battery on the 40A setting (drawing 20A) the car started but quickly stalled. Tried a second time and it started and stayed running. While running the alternator had the battery voltage up to 13.9V. So I put it in the garage and set the charger on 10A. I'll check it tomorrow morning. Will let you all know in about 12 hours.

G'nite.
 

nsaspook

Joined Aug 27, 2009
7,740
That battery is hurt. It'll come back just good enough to leave you stranded in a bad spot. I would not trust it to start on some cold winter night.
 

Wolframore

Joined Jan 21, 2019
1,974
Only way to bring that back is to drain it clean all the sulfates out and replace the acid. The reason why the voltage is so low is because the plates are shorted. I’ve seen AGM batteries come back from 6v before but not standard lead acid.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
5,239
Charger: 12V 10A setting
Battery reading: (8:30 AM Mountain Daylight time)
14.66V with charger on.
Battery reading: (9:00 AM)
13.04V with charger off.
Engine running: (9:03 AM)
14.09V (no charger, running on alternator)

I get it. Not to depend on a battery that has been drained like that. It's why I ask for opinions on the matter. For the next few days I will be watching closely to see how the battery is faring at resting voltages (overnight - before an engine start). If the voltage drops down to 12.2V I'll take it in for warranty. This is not the first time I've drained a battery but it IS the first time I've ever drained one this completely.

As for jumpers - got em. Also have one of those battery boosters. Just so you know, I regularly charge those every 3 to 4 months. Last time it was charged was September.
 

dl324

Joined Mar 30, 2015
11,897
I get it. Not to depend on a battery that has been drained like that.
I had a bad battery that didn't give any symptoms until it took out the alternator. My Daughter was driving to school and she started losing the instrument cluster (speedometer and other gauges started fluctuating). She parked it and I had to try jumping from two vehicles (after my jump starter couldn't do it) before I could get it started.

In addition to needing a new battery, it needed a new alternator.

Don't let anyone besides yourself depend on the vehicle. You wouldn't want them to get stranded.
 

MisterBill2

Joined Jan 23, 2018
7,309
I had a bad battery that didn't give any symptoms until it took out the alternator. My Daughter was driving to school and she started losing the instrument cluster (speedometer and other gauges started fluctuating). She parked it and I had to try jumping from two vehicles (after my jump starter couldn't do it) before I could get it started.

In addition to needing a new battery, it needed a new alternator.

Don't let anyone besides yourself depend on the vehicle. You wouldn't want them to get stranded.
What brand of vehicle was that, model and year if you recall. A group of us drove all over in a 66 Rambler with a battery that barely worked the dome lights. Fortunately it was a manual trans and so whenever the engine died at a light we would jump out and do a push start and not delay traffic more than a few seconds. Did that in a pouring rainstorm once, as well. Fastest push start ever, about 7 seconds. We laughed about that for days.
 

MrSoftware

Joined Oct 29, 2013
1,936
Basically killing it flat dead will sap a lot of capacity. If it's a newish battery then it may still be serviceable for a while. If it's got some years on it anyway, meaning it is already down a lot of capacity from new, then it might be left with a significantly shorter remaining service life.
 

Externet

Joined Nov 29, 2005
1,546
Any lead-acid battery left discharged over 24 hours will never recover it full capability. Can become partially capable, yes. Just use it normally after recharged and replace when gives problems in the future. It will have just a shortened life.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
5,239
Three years into a 5 year warranty. If I bring it back now it'll probably look good and they'll probably not pro-rate it. But for a cheap Walmart battery, I've gotten enough life out of it. After all, the LAST battery wouldn't hold a charge and I got this one prorated already. I don't know if they'll honor the warranty because the original battery (two batteries ago) has already been returned for warranty replacement.
 

MisterBill2

Joined Jan 23, 2018
7,309
Three years into a 5 year warranty. If I bring it back now it'll probably look good and they'll probably not pro-rate it. But for a cheap Walmart battery, I've gotten enough life out of it. After all, the LAST battery wouldn't hold a charge and I got this one prorated already. I don't know if they'll honor the warranty because the original battery (two batteries ago) has already been returned for warranty replacement.
My father-in-law went through 5 or 6 batteries one winter because he was using that brand that got busted for reselling failed batteries. And they kept telling him it was his charging system, which I verified would charge at 25 amps. But he insisted on dealing with the crooks because he did not understand that they were cheating.. So sometimes a warranty and a pro-rating is not even worth the paper it is printed on.
 
Top