How to charge a completely dead automotive battery when it will not take a charge.

Here is what to do when you have a completely dead car battery. One that is so dead the smart chargers will not start a charge. Take a look.

[Ridethebomb]

Two helpful pieces of info I can add to this. you can also put a base level of charge back into a completely dead battery by disconnecting your battery cables ... hooking up your booster for say 20 secs at a time. I needed to do this 3 times to get a base level of charge in the battery so the "smart" charger would recognize that the battery was not completely dead and them it started the charging process.
Second tip: If you are in a hurry to go .... just disconnect your battery cables from the battery and hook your booster pack up to the cables the car will start. Then with the car started carefully replace the cables. If you run the car long enough you will get a charge back into this dead battery.

[mykeelevated]

Worked like a charm brother! Appreciate this ....battery was dead and said it needed to be replaced, etc... - it's at 80% charge and 80% health with a 5 hour charge. ( It started to rain bad so I had to pull it off early )

Car started, up and is self charging now. 🙏

[cyclone]

Thanks For The video. I followed the instructions. Got the dead battery completely charged. Just got it checked over by a battery technician from the auto club. He said it was back to normal. Voltage and cold cranking amps tested in spec and no need to purchase new battery. Saved me $300!

[kennys]

Mine went dead beyond the point where a charger would work a few times, and I just left the charger on it and eventually, or after a day or so, it started charging normally. However, not sure that will always work so glad to know thise useful little trick...thanks.

[ED-cixb]

Very helpful video. I ran into this very problem yesterday with a completely dead lawn and garden battery. I thought my smart charger was not working so I called the manufacturer and they told me that the battery needed to have at lest 2 volts for the charger to sense the connection.

[hardnoxgrad]

I would say the Smart Charger is Not very smart if it can not recognize to start charging all by itself. You are the smart one, because You knew what was needed to tell the Smart Charger to start charging. 🤪🤪🤯

[bluebug]

Just tried it on a battery after I left lights on. Battery was completely drained. Hooked up 4 amp smart charger and nothing over two days. Kept getting dead battery icon. Charger has a gray scale to show charging level. It was zilch! Tried the above method with a fully charged spare battery. Hooked up jumper cables good to bad. Took out my meter and it showed 12.7 volts going through. Hooked up smart charger and immediately gray scale showed charging! I disconnected cables and charger kept charging. Brought battery back to life! Thanks for the great tip. Would have never thought smart charger needed a minimum of voltage to actuate.

[bobbauldock]

See man all them years you didn't know how smart you are, thanks a lot, you hit the nail on the head, I got a 4runner left the back hatch open battery, slam dead, trickle like yours, I have a Sears roll out charger? will try, no good, I will use your method Thanks

[klakklaksd]

Appreciate you, Worked like a charm, short and straight to the point, couldn't get any better 💪

[wallace]

i knew this but how long to charge it? how do y I ubkn[e when its full? i have a 2001 Chevy silverado1500 V8

[UFO_researcher]

Actually, connecting two lead acid batteries together desulfates the battery. However, it also drains the good battery, so it is better to have the other car running and possibly rev the engine over 1300 rpm to activate the alternator.

[JillyBean]

Thank you so much! I was wondering why my smart chargers weren't charging my battery (which was already low) and it was making me super upset. I'm going to try this tomorrow. I have a battery meter so I can now see what the voltage levels are.

[SaabAholic]

I’ve heard of people returning their cheap Harbor Freight car chargers thinking that it’s not working. This is the reason why.

[Browngeezer]

Heyy man, When you jump start it does the other car have to be on, running? If no how long would you say it would have to be connected for and is the a chance you could kill the battery in the other car

[deitricgiles]

How long will it take the dead battery to charge using this process?

[albertomendez]

hi, i jump start my battry, let my car run for 20 min, i turn off the car, i try to start it again, but the the car dint start and das light went off ?
what it will be, shoud i do what is explained in the video?

[javierhermidas]

Same problem thought i was bugging something does stay on

[israelicitizen]

Can this be done with a portable battery jumpstarter + a battery charger?

[thenshoe]

Did you start the car with the good battery?

[tomislavdatyrant]

Car had no fuel w dead battery, jump start gave it some power to power on but engine would not start. I had added 5 gals in too. Doubt the starter or alternator are messed up but how do i get the fuel from the tank into system so the engine can activate?