Ni-Ca Battery Problem

Is this a Nickel-cadmium (NiCd) battery?

http://en.wikipedia.org/wiki/Nickel-cadmium_battery

What size and type - AA, battery pack, camera module format, etc?

What did you do to it? Were you using it and it failed, did you store it and then when you tried to use it later you found it didn't work, etc? Was it leaking or sweating during storage or use? How old is it? How are you charging it? How are you using it?

Are there any other symptoms (crystal formation on the ends, excessive heat, reduced or poor capacity, etc, etc).

Please describe the application and symptoms in as much detail as possible.

If you can even see the electrolyte (never mind the colour) - you've done something very nasty to the battery.

A battery consists of a number of connected cells.Nickel-Cadmium NiCd plated cells use Potassium Hydroxide KOH solution as a colourless liquid electrolyte.Each cell with a norminal voltage of 1.2 volt is often contained in rectangular transparent plastic container.It is boost charged at 1.55V and trigger charge at 1.45V per cell the concentration of the electrolyte is maintained by topping up the level with deionised/pure battery water.

There are cases where some technician top it up with sulphuric acid,H2SO4 mistaken it for lead acid battery and damage the cells instantly.Potassium sulphate,white colour salt is formed in the cell and short circuiting it.

I cannot explain the black colour electrolyte.It could be due to some impurities of electrolyte or electrodes.If you can analyse the elctrolyte to know the contents and may be you can change the electrolyte and save the batteries.

NiCd batteries though expensive are very reliable,very durable and has a predictable life cycle.The NiCd battery with liquid electrolyte has no memory effect as in dry NiCd phone cells.The bigger AH models are commonly used as independent power source for control and tripping supply for HV switchgears.It is also used (in lieu of lead-acid batteries)for the starting of diesel generators that provide emergency supply in high rise buildings.This is a medatory requirement before a building is declare fit to be occupied, in several developing South East Asian countries.

Regards,

Khor.

Ni Cads are so unreliable and can last as short as 1/2 year. Very sensitive to charge memory and cat whisker shorts. My advice DO NOT USE THEM. Use Ni MH or rechargeable Lithium or Gel Lead-Acid.