HOW TO RECONDITION BATTERIES
Anyone can recondition a battery which is past its best, and
you don’t need a degree in electronics to do it. You will need some basic equipment (most of which can be
found at any hardware store), and the ability to follow instructions! Here are a few tips on how to
recondition batteries safely.
(to test the current and voltage of your batteries)
clips (simple wires with clips on the ends for positive and negative terminals)
funnel (for adding chemicals)
There are also a few safety guidelines-mostly common
or overheat batteries-they do not like extremes of temperature
rubberised safety gloves to handle batteries
jewellery, especially rings, as they can conduct electricity
the positive and negative leads on a battery as it can overheat and cause injury
If you use a
multimeter, always connect the leads to the appropriate battery terminal (positive lead to positive terminal,
negative lead to negative terminal)
possible, work outside, or at least in a well ventilated area such as a garage.
or have a naked flame near a battery
Batteries need reconditioning for a variety of different reasons. The main reason is the “memory
effect”, which is caused by recharging batteries before they are fully discharged. The battery then “remembers”
this, and will not hold a charge for as long as when it was new. Another reason is “sulphation”, which is where
the conductive plates inside the battery become coated in a layer of lead sulphate, due to a reaction between
the lead plates of the battery and sulphuric acid.
The methods of reconditioning will be different depending on the individual battery problem. One
method is using an equalising charge on the battery. Another method involves adding chemicals to the battery
itself. Desulphation is the method used to break down the crystalline lead sulphate deposits on the battery
posts (in the case of sulphation), and this involves using a high current pulse to turn the lead sulphate back
into lead and sulphuric acid.
Before you even start, check the battery for obvious problems such as a damaged outer case, low
electrolyte levels, loose cable terminals, or any leaks. Begin by cleaning the posts of the batteries, which
will ensure a good uninterrupted contact.
Test the voltage of your batteries, using either a multimeter or a battery analyser (these should come
with their own instructions for use.) Remember to always connect the positive lead to the positive terminal, and
the negative to the negative. When testing batteries, they should not be under load; ie connected to any other
The battery should read at least 12 volts. If it does not, then you may have a weak or dead battery
cell. To check this, use a screwdriver to pry open the battery caps, and test them using the volt meter. If a
cell measures less than two volts, then it is weak or dead.
Reconditioning rechargeable batteries is pretty simple; just drain them completely of power then
recharge to full capacity again. If this does not work then the battery may need renewing-which again is fairly
simple, but is more involved than simply discharging and recharging.
Battery reconditioning is a very worthwhile thing to take the time to learn, and is fairly simple once
you get the hang of it. Get the equipment, get the instructions-and get reconditioning!