How to Recondition a Motorcycle Lead Acid Battery

LarryC

SToog2
Joined
May 18, 2008
Messages
298
Location
Downers Grove, IL
Bike
1998 ST1100
STOC #
7912
I haven't done any forum searches for this tech tip so am posting it as new. I have personally done this process and it works beautifully. I went from a dead battery to like new for less than $3. Use a bit of safety caution and you can have a like new battery in minutes. (I don't recall where I found it originally).

The information following is general and should be done with gloves, eye protection, adult supervision etc. Will not help a physically damaged battery (broken lead plates).

Clean off the external of the battery so when you take off the acid tank cover, nothing will fall in. Cleanliness is next to Godliness right?

Balance the acid level out among all the lead/acid cells to around 60-75% full. There must be sufficient room to add the cleaning/recharging liquid. (I used a battery specific gravity tester to suck it out to the top of the lead plates). Temporarily store in a glass container. I then took a clean turkey baster and evened out the low battery cells with the full ones.

Next I took the distilled water and heated it to 150 degrees. Slowly stir and mix in the Epsom salts until disolved. For a small motorcycle battery I made excess – 16oz of distilled water with 7oz of Epsom salts (15oz for a quart if you’re doing a large battery). Fill the cells to the low level line with the nice hot liquid and seal them up. Give the battery a good shaking to mix the liquids.

Use a battery trickle charger with a 1 to 2 amp output Don’t use a higher amp charger on the small battery because it will surely kill it (larger auto batteries can take higher amps). Keep the charger on for at least 24hrs.

I drove it to work and later it started right up and has been working great for months. This should last for a while. I understand you can do this up to 5 times. (Two full seasons later it's still working like new).

Items needed:
• Battery to be reconditioned
• Clean ventilated working area
• Large glass bowel
• Distilled water
• Magnesium sulfate (Epsom salts – cheap at grocery or pharmacy)
• Clean stainless pan to boil with
• Liquid thermometer – any kind that reads accurately at 150 degrees
• Turkey baster or some liquid injector
• Goggles and gloves

Please Post back here if you have good luck...
 
Last edited:
Joined
Feb 2, 2009
Messages
2,305
Location
Dahlonega, GA
Bike
2018 NC750X
STOC #
7666
Good info. Have a marginal old batter on the shelf right now I could try it out, could possibly help a stranded ST'er. Thanks
 
OP
OP
LarryC

LarryC

SToog2
Joined
May 18, 2008
Messages
298
Location
Downers Grove, IL
Bike
1998 ST1100
STOC #
7912
Especially those on a limited budget! : )
Just take your time and find a nice uncluttered work space. Then be sure to get a EDBD trickle charger to keep it topped off until needed...
 

Tom Mac 04a

Site Supporter
Joined
Jun 24, 2008
Messages
2,039
Location
LI , New York
Bike
04 ST1300a
STOC #
8347
Don't know if it will work for long... In my younger days, we use to just replace the acid and recharge to get a bit more life

IMHO, while this method may help a dying battery for a short time', nothing will help a badly sulfated, shorted lead acid battery. Maintenance (avoid discharging below 80% full charge, recharge slowly keep charged, use a smart charger, check and maintain fluid levels) is the key to delaying a dead one.

And, NFG on all newer 'glass mat' types which use more of a gelled acid over liquid.
 
Joined
Jan 15, 2009
Messages
353
Location
HolliSTer, CA
Bike
2012 ST1300A
Adding a base agent to one that requires acidity to function makes no sense...nothing personal, but I seriously doubt this works. Batteries are like tires- they wear out and eventually need to be replaced.
 
OP
OP
LarryC

LarryC

SToog2
Joined
May 18, 2008
Messages
298
Location
Downers Grove, IL
Bike
1998 ST1100
STOC #
7912
Doubt all you want, I did this one year ago and my battery holds a perfect charge and starts like new... Sulfation shorts the plates which in turn "kills" the battery. Remove the sulfation and so long as the battery isn't physically damaged it will return to full operation.

Ever wonder what the biggest difference between a 3, 5, or 7 year battery? The physical distance from the plastic bottom of the battery to the bottom of the lead plates...
 
Joined
Jan 15, 2009
Messages
353
Location
HolliSTer, CA
Bike
2012 ST1300A
While similar, there are a variety of ways an SLA battery is made- and only a handful of companies in the world make batteries any longer. Most are antimony/lead, other have a higher calcium component. The chemistry is alike however and dumping an alkaline into an acidic solution will alter the Ph. Acid (its really about 25% acid and 75% water) doesn't wear out- it permeated the lead plates on discharge and is driven from the lead when charged.

Hey- dump some in your gas- I bet your mileage will double! Just chidding, just chidding!

Doubt all you want, I did this one year ago and my battery holds a perfect charge and starts like new... Sulfation shorts the plates which in turn "kills" the battery. Remove the sulfation and so long as the battery isn't physically damaged it will return to full operation.

Ever wonder what the biggest difference between a 3, 5, or 7 year battery? The physical distance from the plastic bottom of the battery to the bottom of the lead plates...
 
OP
OP
LarryC

LarryC

SToog2
Joined
May 18, 2008
Messages
298
Location
Downers Grove, IL
Bike
1998 ST1100
STOC #
7912
Well, since I didn't have an extra $30 at the time to spend on battery equalizer I used this method. So far it appears to have been successful and worked as well on my dead car battery. I will run with it until it stops working and report my findings. I recently installed a digital volt meter to monitor my electrical system so should be able to foresee any degradation in battery condition before imminent failure.

Both batteries (ST and car) still going strong...
 
Last edited:
Top Bottom