Charge your battery correctly, in accordance with its type. Most newer cell phones have lithium-ion batteries, while older ones generally have nickel-based batteries

Store batteries properly. If your battery will be out of use for a while, disconnect it from the phone and store it in a cool place (the refrigerator is good, but freezing temperatures do not slow oxidation) and away from metal objects. Ensure that the battery is not exposed to moisture; try putting the battery in an airtight container or bag. Lithium ion batteries are not rated to operate at refrigerated temperatures, so let the battery sit outside the refrigerator for at least an hour before using it again. Lithium ion batteries oxidize least when they are stored at 40% charge. Never store a lithium battery at low voltage. Recharge batteries after storage.

Clean the battery contacts on the battery and on the phone. Over time, contacts may accumulate dirt. Clean them with a cotton swab and rubbing alcohol to maximize the efficiency of energy transfer. In addition, if the contacts are two different metals, such as gold and tin, accelerated corrosion known as “galvanic or bi-metallic” occurs. Cutting the corrosion from the contacts often requires solvents, such as acetone or nail polish remover. Be careful: these solvent dissolve plastic, so use a Q-Tip to avoid damaging the battery housing or the phone.

Increase Time between Charges

Turn the phone off. This is probably the most effective and most simple way of conserving your battery’s power. If you don’t plan on answering the phone while you’re sleeping or after business hours, just turn it off.

Prolong the Life of Your Battery

Initialize a new battery. New batteries should be fully charged before their first use to obtain maximum capacity. Nickel-based batteries should be charged for 16 hours initially and run through 2-4 full charge/full discharge cycles, while lithium ion batteries should be charged for about 5-6 hours. Ignore the phone telling you that the battery is full–this is normal but is not accurate if the battery is not initialized.

Turn the phone off. This is probably the most effective and most simple way of conserving your battery’s power. If you don’t plan on answering the phone while you’re sleeping or after business hours, just turn it off. Do the same if you are in an area with no reception (such as a subway or remote area, since constantly searching for service depletes the battery fairly quickly. Some phones have an automatic power save feature, but it takes about 30 minutes with no service to kick in. By then, much battery power has been used.

Stop searching for a signal. When you are in an area with poor or no signal, your phone will constantly look for a better connection, and will use up all your power doing so. This is easily understood if you have ever forgotten to turn off your phone on a flight. The best way to ensure longer battery life is to make sure you have a great signal where you use your phone. If you don’t have a perfect signal, get a cell phone repeater which will amplify the signal to provide near perfect reception anywhere.

Switch off the vibrate function on your phone, and use just the ring tone instead. The vibrate function uses up a lot of battery power. Keep the ring tone volume as low as possible.

Turn off your phone’s back light. The back light is what makes the phone easier to read in bright light or outside. However, the light also uses battery power. If you can get by without it, your battery will last longer. If you have to use the back light, many phones will let you set the amount of time to leave the back light on. Shorten that amount of time. Usually, one or two seconds will be sufficient. Some phones have an ambient light sensor, which can turn off the back light in bright conditions and enable it in darker ones.

Avoid using unnecessary features. If you know it will be a while before your phone’s next charge, don’t use the camera or connect to the Internet. Flash photography can drain your battery especially quickly.

Keep calls short. This is obvious, but how many times have you heard someone on their mobile phone say, “I think my battery’s dying,” and then continue their conversation for several minutes? Sometimes, the dying battery is just an excuse to get off the phone (and a good one, at that), but if you really need to conserve the battery, limit your talk time.

Turn off Bluetooth. It will drain your battery very quickly.

Same goes for WIFI, GPS, and infrared capabilities, if your phone has these features built in. Keep them off; save more power.

Use GSM – Using your phone in 3G / Dual Mode will drain the battery quicker than if you just use GSM mode – have a look at your phones spec and you’ll see it will quote two different battery life times – normally 50% more for pure GSM use.