Lithium batteries seem to be everywhere these days. We can find them in our cellphones, laptops, portable media players and etc. We all want to make our batteries last as long as possible, but some well intentioned advice from friends could be harming your lithium battery’s life span. 1. Battery Memory
– When I first got my new cellphone, my friend recommended to fully drain the battery before recharging it. His reasoning was connected to the idea of battery memory. Allowing the battery to fully discharge then recharging to max, supposedly gives you the complete battery capacity. Otherwise, if you simply charged from the half way point to max battery capacity, the battery would treat the half way point as the empty point, thus cutting your battery capacity in half.
Problem is battery memory doesn’t apply to lithium batteries, this advice was meant for nickel based batteries. Fully discharging your lithium battery frequently can actually be quite harmful to your battery’s health, possibly rendering it completely unusable if energy levels go too low.
The good news is today’s lithium batteries have a safety circuit in place to insure the battery doesn’t reach the point of no return. The safety circuit isn’t fool proof though, if you leave your battery completely drained for a few days, even the circuit’s protective measures won’t save it.2. Battery Calibration
– There are some benefits to fully discharging your lithium battery periodically, for laptops this can be especially important. If you start to notice your battery meter becoming more and more inaccurate, it may be time for some battery calibration. Allow your lithium battery completely drain, then charge until the battery is full again. This will calibrate your battery giving you more accurate readings. This should be done once every 30 charges or when you notice battery readings are off.3. Consequences of Heat
– Another enemy of lithium battery life is heat. If you were to leave your laptop plugged in and running for a year, you should expect the lithium battery capacity to be anywhere between 60% to 80% of it’s original max capacity. This is why people that use their laptops as desktop replacements will notice greatly reduced battery life performance after one year of use. This issue can be resolved by removing the battery while using a corded power source. Now you may want to check with your manufacturer ahead of time to check for safety concerns, some manufacturers have mentioned problems such as moisture and dust collecting in the battery casing.4. Battery Storage
– If you don’t plan on using your lithium battery for prolonged periods of time, then you’ll want to reduce the charge level to 40% and place the battery in the fridge (not freezer). Storing the battery at 100% charge level applies unnecessary stress and can cause internal corrosion. On the other hand, if the charge is too low, the battery can become permanently unusable, due to battery self discharge. This is why manufacturers recommend storing your lithium batteries at 40% charge, rather than either extreme.Quick Overview
- Try to avoid frequent full battery discharges.
- For lithium battery calibration, periodically do a full battery discharge every 30 charges to increase meter accuracy.
- Avoid heat, heat is the lithium battery’s enemy, the temperature in a car can easily rise 50F in a single hour, in some cases reaching 140F.
- For proper lithium battery storage, be sure to have the battery charge level at 40% and place in the fridge (not freezer) for maximum battery longevity.
For additional information concerning batteries in general, I strongly recommend visiting Battery University