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 of course, if you leave your battery completely drained for a few days, even the circuit’s protective measures won’t save it.
2. Battery Calibrating
There is some benefits to fully discharging your lithium battery periodically, for laptops this can be especially important. If you start to notice your battery meter is becoming more and more inaccurate, it may be time for some battery calibration. By allowing your lithium battery to fully drain, this will help the battery recalibrate allowing for more accurate measurements of battery life. 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 plan on not using the Lithium battery for prolonged periods of time, then you’ll want to have the charge level at 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 battery at 40 % charge, rather than either extreme.
- Try to avoid frequent full discharging of the Lithium battery.
- For lithium battery meter 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 140 F.
- If you plan to place your lithium battery in storage, be sure to have the charge at 40% and stored in the fridge (not freezer) for maximum battery longevity.