Instructables

Aluminium Sulfate Lead Acid Battery Conversion

Picture of Aluminium Sulfate Lead Acid Battery Conversion
quick how to on aluminum sulfate electrolyte for lead acid batteries.
 
Remove these adsRemove these ads by Signing Up

Step 1: Purchase Ingredients.

Picture of Purchase Ingredients.
0.9773286698904088IMG_20131130_111028.jpg
0.14859098093977574IMG_20131130_111009.jpg
you will need aluminium sulfate, a hydrometer, distilled water and a two buckets.

also you will need a face mask. long sleeves, safety goggles and water on hand.

this job could cause death or serious harm from explosions and acid spills.

you will also need a battery charger, applicator bulb and common sense.

Step 2: Drill Holes Into Vent Caps Or Remove Caps.

Picture of Drill Holes Into Vent Caps Or Remove Caps.
if you have a sla battery you will need to drill into the plastic.

use a pneumatic drill a regular drill could cause sparking or explosions.

you have two choices.
1.fully flatten the battery to sulfate the plates. this will produce a super saturated acid.

2. fully charge the battery. check with hydrometer that the electrolyte is 12.5 to 13.00. this indicates 80 to 100% charge.

Step 3: Create Saturated Aluminum Sulfate Solution.

Picture of Create Saturated Aluminum Sulfate Solution.
you will need room temperature distilled water. add aluminium sulfate slowly to water while stiring. check with hydrometer.
it takes a long time but you should be able to get a reading of 12.5 or more specific gravity easily.

if you heat the water or add too much the aluminum sulfate will precipitate when the electrolyte cools.

Step 4: Tip Out The Acid From Battery.

Picture of Tip Out The Acid From Battery.
pour out acid from the battery into a large bucket. be carefull not to spill any on yourself.

Step 5: Add Electrolyte

Picture of Add Electrolyte
add aluminium sulfate solution to each cell. use a bulb designed for this purpose. about 5 bucks from auto store.

feel free to use any ratio. I have found 20% sulfuric acid to aluminium sulfate works the best.

100% tends to precipitate and provide low cca.

Step 6: Charging

Picture of Charging
you will need to charge the battery to 16.8v. this electrolyte solution doesnt off gas as much as battery acid.

gassing starts at 14.7v and gets rapid at 15v plus.

I use a turnigy charge set to 7 cell mode. it will cut out at 17.1v. but the battery only reaches 16.8v so you need to turn it off manually.
jolshefsky3 months ago
Any idea what the chemical reactions are? As far as I know, a sulfuric acid and lead battery discharges when the negative electrode combines with the acid to make lead(II) sulfite (PbSO4) and gives off some electrons; the positive electrode is lead oxide (PbO2) when charged and takes some electrons with the acid to make lead(II) sulfate (PbSO4).
speakerbox (author)  jolshefsky3 months ago
I dont know. I put a lead and lead oxide plate in the solution and discharged them to see what it was.

The plates did not go white. I think it may be aluminum.

But as a layman I cant say for sure. Wish I knew...

Btw there is little or no charge when you add the solution. Also they self discharge in a matter of weeks.

This was my last experiment after trying to resurrect dead batteries. The whole battery rejuvenation idea is bunk imo.

Moving on to hho to see if there is anything to that.
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!