Battery Reconditioning 101

In this article I will be analyzing different methods to revive old or dead batteries. I won't go threw all the reasons why one should try to recondition batteries cause the reasons are obvious. I will be using 6 dead or almost dead golf cart batteries for testing, voltages vary from 2 volts to 6 volts.

Method #1 Charge/Discharge
This method is a simple cycling of the charge and discharge until enough of the hard sulfate is dissolved back into the electrolyte (if it is still possible).
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1. (pic 1) Clean the battery
2. (pic 2) Add distilled water to the electrolyte if needed.
3. (pic 3) Clean the posts with a wire brush.
4. (pic 4) Starting voltage 2.672.
5. (pic 5) Voltage with the charger connected.
6. Charged the battery for 24hrs and the terminating voltage was 6.561 volts
7. Discharged with a CBAIII for the entire day at 5amps but we had a power failure at the end of the day and the laptop that I was using died after only 2 minutes on it's battery (wow another dead battery), which ruined our data for the 1st discharge cycle.
8. Repeat steps 6 and 7 till there is no more noticeable improvement, if any at all.
*note* On the 2nd 24 hour charge cycle the battery's terminating voltage was 6.88 volts and on the 3rd charge cycle it went up to 6.95v, 4th 7.02, 5th 7.07.
*note* I will continue cycling the battery (gc1) till either the terminating charge voltage reaches 7.25 volts or it just won't charge that high. I will continue to update this post with the final results when they are available.


*UPDATE* I'm extremely pleased with the results of this first method to revive dead batteries, as the data of the charge/discharge cycles for golf cart battery #1 came in and I was seeing positive results, I started the same method on golf cart battery #2 with the same results.

Battery #2 now on it's 8th charge cycle has a terminating voltage of 7.20 volts, another .05 volts and it will also be ready to be put back in use.

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(pic 6) is battery #1 on it's 7th charge cycle showing a voltage of 7.14, it actually went up to 7.15 just after I shut the camera down hehe.
(pic 7) is battery #2, identified as (GC2) on it's 7th discharge cycle.
(pic 8) These are 3 other golf cart batteries waiting to be revived. the 1st battery is currently hooked up to a small bedini pulse charger which is only pushing it up to 6 volts.
(pic 9) is the laptop I'm using along with a CBA III to monitor the charge/discharge cycles.

Method #2 Use chemical addition:
This procedure uses a common chemical that you can buy at almost any drug store. The chemical is magnesium sulfate, but it is better recognized by the name Epsom salt. Here are the steps for using Epsom salt for battery reconditioning.
  1. Measure out about 7 to 8 ounces (250 grams) of Epsom salt.
  2. Heat about 1/2 quart of distilled water to about 150oF. This is very hot but not boiling. It doesn't have to be exactly 150oF, but does need to be hot or the Epsom salt won't dissolve.
  3. Add the 7 to 8 ounces of Epsom Salt to the 1/2 quart of hot water and stir until it is all or almost all dissolved.
  4. If you haven't already done so, the battery caps need to be removed or holes drilled into each cell in a sealed battery.
  5. If the battery has electrolyte up to the proper level (battery plates completely covered), then remove about 1/2 quart of liquid from the cells of the battery, taking approximately the same amount from each cell.
  6. Using a small plastic funnel, add the 1/2 quart of Epsom salt solution to the battery, putting approximately the same amount into each cell, and making sure that the plates are all completely covered.
  7. Put the battery caps back on or put plastic plugs into the drilled holes and shake the battery to make sure that the Epsom salt solution is well distributed in each cell.
  8. Charge the battery completely, then discharge it to 50% and recharge it a couple of times and test to see if the chemical addition has helped the battery.

Update 2 Aug 2016:
Battery (GC3) was charged for 48 hours and after resting for a couple of hours the standing voltage was only 4.36 volts. Hydrometer readings identified one of the cells as being completely dead so I removed some of the electrolyte from each cell and proceeded to add my chemical solution the the cells then started a charge / discharge cycling on it.

Update 24 Aug 2016:
(GC3) has gone threw the charge / discharge cycles 4 times now and still only has a standing voltage of 5.38 volts, also after doing the hydro meter test, the damaged cell still does not seem to be recovering.
I'm going to try adding more of my chemical solution then do a few more charge cycles and if nothing happens I'll try my pulse charger, if all methods fail I will dismantle the battery and have a closer look at it :)