Rechargeable batteries are everywhere these days: cordless tools, laptop
computers, cordless phones, and cell phones, just to name a few.
What’s more, the pesky things are always wearing out, not taking a charge, or
running down in a very short time. Well… now there’s something you
can do about it!
This publication contains a lot of information about
rechargeable batteries, such as the different types, how to take care of
them to make them last longer, how to test one to see if it can be
reconditioned, how to recondition rechargeable batteries for electronic
devices, and finally a section on reconditioning car batteries. You can use
this information to take care of your own rechargeable batteries, to help
out your friends, or perhaps even to make some money on the side with a
Why Do Rechargeable Batteries Need to be Reconditioned?
When you first buy a device with a rechargeable battery everything works
fine. You usually plug it in to fully charge the battery before using the
device. Then you use it for awhile and when it needs charging, you plug
it in again. This goes on for quite awhile.
Just like most everything else
in this world, however, rechargeable batteries wear out too. This wearing
out often shows up as less and less useful time between the need to charge
the battery again. Often the battery is then discarded and a new one is
purchased. In many cases, however, doing the reconditioning described
in this book will bring the battery back to life and make it work almost
like new again.
The decreasing useful time between charges for a rechargeable battery is
due to what is called the memory effect. The type of battery most subject
to the memory effect is the Ni-Cd.
The newer Ni-MH are affected to a lesser extent– more about that later. For these type batteries, it is helpful
to allow the battery to discharge nearly completely and then charge it
If you frequently allow the battery to discharge only halfway
before recharging it, the battery “remembers” that and loses the ability to
The actual cause for the memory effect is growth
of the originally finely divided crystals inside a Ni-Cad battery.
Thedetails of that are not really important here. What is important is the fact
that this process can often be reversed and the battery can be revived
using the procedures described in this book.
Another important thing to keep in mind is that doing some preventive
maintenance (tender loving care) as described in a later section can keep
your batteries going longer with good performance.
You may have noticed that car batteries wear out also, usually at a very
inconvenient time and place! The reason that automobile (lead acid)
batteries wear out is different than the reason that Ni-Cd and similar
Lead acid batteries don’t suffer from the memory effect, so
it doesn’t matter that the battery in your car gets recharged whenever the
car is running, even though it is not completely discharged. In fact it is
bad for lead acid batteries to allow them to discharge completely.
cause for lead acid batteries wearing out is the effect of undesirable
chemical reactions that take place slowly within the battery.
Once again the details are not important to us. In this case also, however, many
“dead” lead acid batteries can be brought back to life, using the
procedures outlined in this book, so that they work properly again.