How Long Do Cordless Phone Batteries Last?

If my cordless phone has a short talk time then it is time to replace the batteries. The lifespan or longevity of your batteries is dependent on the number of cycles for a given time period. This is sometimes described as the number of times you replace your handset on the base unit. BT recommend replacing your cordless phone batteries every twelve months. How long do batteries last in a cordless phone.How Long Do Cordless Phone Batteries Last

The answer to how long do batteries last in a cordless phone? is a typical high quality NiMh cell or battery pack as most often used in phone batteries has between a minimum of 500 cycles and a maximum of 1000 cycles. As the number of cycles increases the run time or the time the handset can be off the base unit decreases pro rata.

So this means that you should replace your handset when the battery requires recharging or put another way, as infrequently as possible.This of course causes a dilemma as you may use your phone on the last day of useful charge and have either a short or long conversation.

As the overall objective is for the phone not to fail, either just before or during a conversation a compromise must beHow long do cordless phone batteries last reached.

If we take the average at 750 cycles then replacing the handset once in every 24 hours would give 750 days or just over two years of high performance use and every 48 hours just over 4 years.

However NiMh cells do not suffer from memory affect as did older Ni-cad cells. So you can leave the handset on the base unit for long periods and remove it for a short period perhaps to make a call. This would not constitute a full cycle although there would be some degradation of the cells.

There are also other factors that will affect the lifespan of your batteries please see our other articles.

So where does this leave us. In short every user has a different lifestyle requirement and assuming that you follow the advice given on the links above, then it is best to use the phone as you require. Some will experience longer periods between replacing their batteries than others providing the batteries are of the same quality and all have followed the initial best practice information.

For further information on the different battery chemistry types, charging regimes etc. We would recommend Wikipedia.

You may wish to discuss your individual requirements if so, please email me and I will be happy to advise or recommend another authority that can give advice that best suits your requirements. Further reading can be found in the London Economic. 

By G. Moore BSc (Hons) 23/06/2003