It has happened to just about everyone, you replace your batteries and then they die at the most inopportune time. Why does this happen? To help figure this out you have to know how a battery is made.
How Batteries Work
Batteries are an electrochemical cell. The cell works by creating a reaction between two different metal solid electrodes with a solution containing the same metals in a aqueous solution. A positive electrode is connected to a negative electrode. When you charge your battery you repel the ions from the positive electrode to the negative electrode. When you use the power from your charged battery you are using the energy from the reverse process where the ions are released.
Over time this process becomes less effective as it starts to build up on both electrodes and the battery starts to lose its capacity to charge and create power. This process is irreversible and unavoidable.
How Can I Make my Battery Last Longer
Even with the best of care, your battery will die. Manufacturers do their best to give you a good estimate of how long your battery should last, but those estimates don't take into account the kind of use and abuse your battery will go through.
The number one killer of a battery is heat. If you are using your battery in a hot environment and have no way to reduce the heat, know that your battery will not last as long. Do what you can to not expose your battery to high amounts of heat. For example, be aware of leaving your battery in a parked car. If you are using a laptop, make sure your battery has adequate ventilation. You can improve ventilation by raising your laptop. Some extended batteries not only provide longer lasting power, but better ventilation by raising your laptop. You can see more tips for Extending the Life of your Laptop here.
You will also want to use your battery as it is meant to be used. That means charge it up and then use it. Don't always leave your battery plugged in. Don't store you battery when it does not have at least a partial charge.
When your battery does die, it is time to replace them. Of course we recommend that you check out Batteryheads.com to get great replacement batteries at competitive pricing.