Repair Sealed Lead Acid Batteries

Introduction: Repair Sealed Lead Acid Batteries

About: I need more space for my projects, my garage is packed. I like to make things, I've always got a project on the go.

Has your battery lost some of it's capacity?

It turns out that Sealed Lead Acid (SLA) batteries are not infact all that well sealed. You can perform maintenance on them much the same as you would any other wet cell battery, such as car batteries.

In this instructable I will show you how to do this.

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Step 1: This Is How We Do It

What you will need:

-Distilled water

-Small straight screwdriver

-superglue or hot glue

-a syringe or pipette

Safety Considerations:

Wear safety goggles and gloves as the fluid in the battery is generally sulfuric acid

How to go about it:

1/ Remove the cover on the top of the battery using a small straight screwdriver.

2/ You will find little rubber or plastic caps on the individual cells of the battery, remove these.

3/ Using your pipette or syringe, fill the cells of the battery until the lead plates inside the battery are submerged, you will be able to see through the hole.

4/ In a ventilated location, connect a charger for an hour with the caps off. If you have over filled any of the cells any excess acid will bubble out. With your gloves use a bit of paper towel to soak this up and dispose of it in a safe manner.

5/ Replace the caps and then using your adhesive, stick the cover back over the caps.

6/ Give it a good charge and it should have a better current capacity again!

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3 Discussions


3 years ago

Hi...I tried this method with 12v sealed battery and charged it for 12hr with connection source +'ve to battery +'ve and source -ve to battery -ve but it's not charging more than 1V...ways a problem...


3 years ago

This is good to know. Thanks.