Li-Ion batteries - What about rebuilding or replacing them ?


Li-Ion = Lithium Ion rechargeable battery.  Single cell = 3.6V empty, 4.1 Volts full  

Li-Ion batteries require a special charging system.  Other types of batteries may not be substituted.   If your electronic appliance operates from Li-Ion batteries - it must be replaced with Li-Ion.

Because of the cost and short life span of Li-Ion batteries we receive many requests to rebuild them.  Unfortunately we must refuse to rebuild Li-Ion batteries at the present time.    Li-Ion cells are not readily available.  The single cells that would be required for replacement when rebuilding a battery are not offered to the open market.  They are controlled by the manufacturers to be used only in approved designs and by original equipment manufacturers.    There are many dealers selling Li-Ion on eBay - they can only be old cells or removed from equipment.  The cells are only part of the problem.  There are charge controls and safety circuits that must be tested, and properly connected when replacing the original cells.
A safety circuit PC board is attached to the cells to control temperature, voltage, and current, flowing to - and from the cells.
Each battery pack is made with a specific circuit that is exclusive to that specific design.   Some batteries have a programmed chip - if the voltage has been allowed to drop so low as to lose the program, or if we fail to transfer the data to the new cell stack, the new pack cannot be charged  (Usually found in Laptop applications).
The recommended use instructions from the manufacturers, include some pointers that are nothing less than beyond normal human behavior.
When storing them ( as in not discharging or charging them )
for any length of time ( as in 3 weeks or a month )
They must not be stored full -
they must not be stored empty -
they must be stored at approximately 33 % of full capacity ( and never below freezing )
Failure to do so will cause long term damage ( as in reduced performance per charge and a shortened life.)
( It's your guess as to how to know that the battery is charged or discharged to the  33% point. )
Never discharge them to the full extent - discharge to a level that uses only 80 to 90 % of capacity.
If you discharge them to empty - there is a low voltage safety circuit that will cut off the output.  The pack will read zero volts.  When the drain is removed - it may, or may not recover to a voltage high enough to reconnect the battery.   Most chargers are designed to attempt to bring the voltage above the cut off level, by using a very low periodic charge pulse - even so - if the battery has been below the safety level for very long - the charger may never be able to recharge the pack.
Never over charge them - if they are not being used - do not keep charging them - there is a high voltage cut off in the safety circuit that works similarly to the low voltage cut off.  It will recover once removed from the charge circuit - but be informed that if you continue to charge when full - the cells will fail at an early age. (Sooner than expected - what ever that is?).

Never attempt to charge Li-Ion batteries in below freezing temperatures.  Serious and permanent damage may occur.

If you take out all the "do nots" you realize - when you own a Li-Ion battery - keeping it alive and well - is similar to owning a work horse.
You must never feed it too much or it will not want to work.
You must always feed it something or it will get weak and die.
You must make it work nearly every day - or it will get lazy and not want to work.
You must never work it too hard before you feed it - or you may kill it.
If you ever let it go to sleep on a full stomach - it will get weak and may die at an early age.
If you ever let it sleep too long on an empty stomach - it will get weak and may die.
If you try to feed it when the temperature is below freezing - it may have a stroke and die.
Had enough ? - there is more ... the life of a Li-Ion battery pack is intended to be about 3 years (if treated perfectly). 
The battery manufacturer considers the life of the product in which they are used - to be about the same time period.
Apple used them in the IPOD.   When the million or so customers discovered that in 18 months to 2 years the battery was no longer working - they contacted Apple to learn that the $ 300 to $ 400.00 digital player was now thought to be at the end of its life cycle.  Apple considered the cost to replace the battery would be higher than the cost to buy a new IPOD.

We sincerely wish we had an answer to the rebuilding or replacement issues of Li-Ion.  We never give up - so check again, given time, we may find a suitable method for servicing them.




Primecell  Division,  Cunard Associates Inc. ~ 9343 US RT 220 ~ Bedford PA 15522 ~  24 Hr Message  (814) 623-7000

Copyright 2000  Primecell (TM) .   All rights reserved.    Revised:January 08, 2009