You might think these things are just pieces of junk in your garage, but if you learn how to revive dead batteries, you can actually use them again! The only reason you're not using a dead car battery is due to its inability to provide the amperage to start a car. Still, even if they can't help your car, the truth is, they're still useful for other pieces of equipment. But first, you need to know how to rejuvenate a lead-acid battery.
Revive Dead Batteries | Restore Sealed Lead Acid Battery
What You Will Need:
- Dry Cloth
- Razor
- Flat-Head Screwdriver
- Water
- Battery Charger
- Meat Syringe (Optional)
- Multimeter
Let's get to work!
Step 1: Clean the Battery
You've probably heard of using Epsom salt to revive dead batteries but that has not worked for everyone. This guide will take an alternate route and see if this one works for you. The first step in how to fix a dead car battery is to clean up the outer casing. Spray some biodiesel, olive oil, or kerosene, then wipe it with a dry cloth. You can skip the cleaning if you want, but it's always good to start working without the mess.
Step 2: Remove the Top Cover
Go around the edge of the top cover using a razor blade to the point of being able to detach it. You can also use the razor to lift the cover. Please be extra careful when holding the razor. As soon as you see a lift, slowly switch to a screwdriver. Gently raise the top by working the screwdriver under the case.
- Extruded handle
- Satin blade
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Step 3: Fill the Cells with Water
Take the caps off so you can fill each cell with water. You can use a meat syringe to fill a single cell with 20 to 30 milliliters of water. A dry battery usually takes one full syringe, but it's okay to use any method you're comfortable with, as long as you completely fill each cell.
Step 4: Start Charging the Battery
You can start charging the battery now. This demonstration makes use of Da Pimp charger, which is also a portable battery tester. Place the leads for the DC side correctly on the battery. It's as easy as “black to black” and “red to red.”
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Step 5: Leave the Battery Charged for 15 to 20 Minutes
You may see a really bad voltage reading before you start charging the battery. Let the charger work on the battery for 15 to 20 minutes, then check the voltage reading again. If the reading shows pulsing signs, try to give it 15 minutes more until the voltage reading stabilizes.
Step 6: Check the Voltage Reading of Each Cell
Now, you can turn off the charger and check the voltage reading of each cell. At this point, you will know if any of the cells are dead or weaker than the others. With the use of a multimeter, set it to voltage DC with the positive probe on the positive terminal of the battery and dip the negative into the acid for each cell. You'll get different readings, but it will let you know if any of the cells are dead.
SOLA WIND UP CHARGER This mini and suitable hand-winding charger is designed for emergency or outdoor use.
That's just about all that's needed to be done for a sealed lead acid battery recovery. Easy work for anyone!
- 22Ah Clore Proformer Battery designed for Jump Starting
- 46" Heavy-Duty #2 AWG Cables
Last update on 2026-05-20 / Affiliate links / Images from Amazon Product Advertising API
Here's the full video by The Good Life Lab on recovering an old sealed lead acid battery:
Isn't finding a good use for things sitting at the corner of your garage neat? Reviving dead batteries is a handy skill to learn. Furthermore, it won't take much of your time to recover an old lead-acid battery. Try using them in your house for small low voltage devices. For example, you can use them to power a small fan, a desk lamp, or even for emergency lighting. You can use the battery as a power source for a lighting system in your house or use it for whichever device you please.
Have you tried to revive dead batteries? Share your experiences in the comments section below!
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Editor's Note: This article was first published in November 2017 and has been updated for quality and relevancy.
