The batteries used in our smartphones are getting better all the time but they're still far from immortal, which you've probably noticed if you've used one for 18 months or longer. 

Rechargeable batteries don't last forever, but most of us don't recharge correctly to ensure that we get as many charge cycles out of our batteries as possible. Here's a few counterintuituve but critical tips to squeezing the most juice out of your power pack for as many months as possible. 

1. Don't charge to 100 percent 

Studies have shown that filling your electron tank up to the brim can actually damage the battery and reduce its lifespan. Devices and data differ as to how much you should fill up your battery with each charge, but lower is better. So it becomes a balance of practicality and longevity. A good rule of thumb seems to be to never charge your phone up to more than 80 percent of capacity. Some research shows that after 80 percent, your charger must hold your battery at a constant high voltage to get to 100 percent, and this constant voltage does the most damage. 

Apps like Accubattery can set alarms and send notifications to your smartwatch when your phone reaches 80 percent and it's time to unplug. 

2. Lay off the turbo charging

Fast charging power adapters and other turbo charging tech is super handy when you need a little juice boost in a pinch, but for much more than that, they're potentially detrimental to your battery. The idea with turbo charging is that it can quickly add power to a depleted pack, but you've probably noticed diminishing returns using a fast charger as your capacity approaches 100 percent. 

This turbo mode can increase the voltage and heat to your battery, two factors that shorten its life. As such, it should be used sparingly and only when the battery is below about 50 percent. Definitely don't leave your phone connected to a fast charger overnight.

3. Keep it cool

Heat and high voltage are the enemies of long battery life. You should do everything you can to keep your phone cool as much as possible, including keeping it off hot dashboards and powering it down when it starts to overheat from prolonged heavy use. 

For charging, this means keeping it in a well ventilated place and maybe even considering taking its case off while it's plugged in. You definitely don't want to slip a charging phone under your pillow where it won't have any ventilation. By the way, this is also a legitimate fire risk, so just keep that charging phone out of bed. 

4. Let it charge in peace

Another reason to let your phone be while it's re-energizing is that there's evidence using your phone while charging - especially for processor-intensive tasks like watching videos or gaming - can disrupt the charge cycle and reduce battery life. 

So, the main takeaways here are to do whatever you can to keep your battery cool, and to charge often for short periods of time rather than overnight. It's not quite the way we've been taught to use our phones, but phone makers aren't necesarrily interested in making sure we get as many charge cycles as possible out of our batteries. 

Although I suppose phone manufacturers might argue that it's quite convenient that a brand new model tends to come out every year, probably right around the time your turbo-charged battery is starting to age...