Batteries, we can't live without them, be it to power the clock on the wall, the TV remote, the smoke alarm, or the children's games console controller.

In the office, how many disposables are used by your company each year in wireless keyboards and mice? If each employee uses 12 AA batteries a year and you have 100 employees that's around £1,200 a year on batteries!!!

The amount of disposable batteries we get through over our lifetime beggars belief, and they're not cheap. So, given that they come in a re-chargeable option how much is it possible to save using the re-chargeable ones and what are the advantages/disadvantages of re-chargeable over disposable batteries?

Researching this I came across many claims that re-chargeable batteries can be re-charged anywhere between 500 and 1000 times. Let's take the middle ground for the purpose of this exercise and assume that they can be recharged 750 times.

The Maths (or Math for our North American readers)

I've tried to estimate how many disposable batteries we (as a family of 4) get through each year and came to the figure of 36 batteries spread across 15 different appliances, some replaced on a regular basis throughout the year and conclude that we get through around 60 batteries a year. Assuming each battery average cost to be £1.00 each, that's £60 a year (assuming a mix of AAA, AA, 3V etc).

If the average re-chargeable battery costs £2.50 and is capable of being re-charged 750 times then replacing a disposable with a re-chargeable, should, if my maths are correct, save me £747.50 for each battery. If I extend this saving to the 36 batteries in my house, the saving as a household is £26,910……..That can't be correct, I hear you say, (I said it to myself) because if that's the saving then switching to re-chargeable batteries is a no-brainer.

Let's take away the maths for a minute and apply some common sense. There are some batteries which might last 5 years like the one in my digital alarm clock. I'd never need to use a re-chargeable capable of being re-charged 750 times in this clock as I'll be long dead by then. Also the life of a re-chargeable battery is not as long as a disposable so will need to be replaced more frequently and you need to buy a charger and pay for the electricity to charge the batteries etc. So let's reduce the saving of £26,910 by 33%…….that still leaves a saving of nearly £18,000….a staggering saving.

But, hang on a minute, I'm currently only spending £60 a year on batteries. If I assume my life span to be 70 then 70 x £60 = £4,200 saving. A far more believable figure but one which still can't be ignored.

There's no denying the fact that switching to re-chargeable WILL save you money and an additional environmental benefit will be that over your lifetime you will be keeping thousands of disposable batteries out of landfill sites.

Key facts on Re-Chargeable Batteries

* Battery Life

Rechargeables will discharge over a period of weeks. Disposables can be left in a drawer for years, and in equipment for months. Don't use re-chargeable batteries in things such as smoke alarms or the torch you keep in the kitchen drawer in the event of a power cut.

* Environment

Many of disposable batteries today can be disposed of in the dustbin but ALL re-chargeable batteries should be re-cycled.

* Re-chargeable battery type

Nickel-Cadmium (NiCad). These are old technology now and are less frequently used nowadays because of the toxic nature of Cadmium.

Alkaline. Not to be confused with normal disposable alkaline batteries, re-chargeable alkaline batteries are the cheap and cheerful option from among the range. But you get what you pay for as they have poor long term performancein comparison to other re-chargeable battery types. NEVER try to re-charge disposable alkaline batteries.

Nickel-Metal-Hydride (NiMH). A great rechargeable, especially for appliances with medium to high power usage. A lot of manufacturers are switching from NiCad to NiMH as they don't contain toxic heavy metals and early problems with rapid self-discharge have been eliminated.

Lithium-ion. The Rolls Royce of re-chargeable batteries in terms of price and performance. They can sit unused in a drawer considerably longer than other types without discharging and are a great choice for high-drain appliances such as cameras, phones, torches.

* Charging

Two things to remember. Firstly, try to nearly exhaust a battery before re-charging, but never run it completely flat. Battery 'memory' is nowhere near as prevalent in today's batteries but is still a factor, particularly with the cheaper NiCad. Secondly never overcharge a battery. Always invest in a battery charger which will detect full capacity and stop charging.

Finally

The savings are substantial whichever way you look at it. Disposables still have their place but re-chargeables could and probably should replace most of the batteries in our home and workplace. Buy a good charger and re-chargeable battery and they should last you many many years.