Billions of calls, texts and video messages are sent between mobile phones around the world every day, and on top of that phones are coming packed with more and more functionality, from digital cameras with many megapixels to full blown gaming functionality and the ability to surf the web at broadband speeds. However, producing phones that can do all of this requires power, and power requires a battery that is able to cope with running loads of stuff and still leaving you enough juice to make a call. That`s why the battery technology in mobile phones is always changing and there are several different types of battery on the market that you might consider if you`re replacing your old battery or just want a spare one charged up and ready for an emergency.

Nickel Cadmium or NiCd
This is one of the oldest types of battery around, with the first version invented 110 years ago. Things have moved on a lot since then, and it NiCd batteries are used in a variety of mobile phones, and are well known for their durability and relatively stable chemical construction and though they are slightly more expensive than their competitors they can handle more charging and discharging over their life time. One problem is that if you don`t allow the battery to fully discharge and recharge it mid way through use it will `remember` the point at which you did this, and suddenly loose charge again at this point, so it`s important to fully use up all the power on the battery before you recharge if your phone uses NiCd batteries.

Nickel Metal Hydride or NiMh
NiMh batteries are used not just in phones but to power hybrid electric cars, and they are considered to be more environmentally friendly than their NiCd brothers because they have no toxic components. NiMh are often cheaper than NiCd batteries as well, however they do suffer more from a gradual de-charge or leaking over time, so if you don`t use one for a while it will gradually run itself out of electricity, which could be a problem if you need to use it in an emergency. However, the most modern NiMh batteries have been adapted to cope and have longer charged shelf lives, so make sure you choose wisely.

Lithium Ion or Li-Ion
This is currently the most popular kind of battery you`ll find in anything from mobile phones to digital cameras, primarily because it can be made in a much smaller form than the other types of rechargeable battery but still hold just as much energy, which is great for companies making mobile phones smaller and smaller. Sadly over time, no matter how much you use it, an Li-Ion battery will loose performance.

The best way to pick up batteries and accessories for your phone, whether it`s a Nokia mobile or an LG, is to check out the various discounted online stores who specialise in batteries of all kinds. They will no doubt provide advice and help with choosing your mobile phone battery.