Is it better to completely drain my rechargeable batteries every time?

I want to occasionally completely discharge my NiCad batteries. What is the best way to do this?

• I believe that NiCad batteries have a "memory" - so they should be completely discharged occasionally. What is the best way of doing this? I have sometimes put the NiCad batteries in a torch, and left it switched on for 24 hours, but this does not completely discharge the batteries. I also have a fairly ordinary battery charger, which has a switch that you can put to "charge", "discharge" or "test" position, but this works so slowly that it is not worth doing. What I really need is a simple device that I can put the NiCad batteries in to drain all the current out of them in a reasonable length of time. If I could buy this device, I would, if it is not too expensive. I don't want to make my own device, unless it is foolproof, in case it it is dangerous when discharging the batteries. I have looked in catalogues (Maplins, etc) but cannot find anything that would do this job.

• Answer:

  Unless your batteries are used in a continuous timed manner such as might be with a hand held radio in an industrial setting, where the radios were charged at the end of every work shift, NiCad memory isn't the problem it is reputed to be. I have used a 50 ohm, 20 watt resistor placed across the small battery's poles to discharge them with success. However it should be noted that a TOTALLY discharged NiCad battery is suseptible to reverse charging if placed incorrectly in the charger. The original "positive" pole will become the "negative" and vise versa. Not a good idea for NiCads. Probably best to use the "discharge" function of your charger despte the time required, and not take chances, eh? Another idea would be to replace them with Lithium Ion (Lithium) batteries which are not suseptible to the "memory" effect. Effective, but expensive. Ouzinki (36 years as an electronics technician)