Whether it's the batteries in your smartphone, your notebook, your tablet or your e-bike, there are persistent myths about the mobile power sources for all electronic equipment. But which ones are nonsense and which have a grain of truth? Four experts weigh in for an oversight of battery safety and efficiency tips.
Myth: The battery should be completely empty before you charge it.
Correct - but not for today's batteries.
"Nickel-cadmium batteries, which used to be used before, suffered from the so-called memory effect," says Tobias Placke from MEET, a battery research centre at the University of Muenster in Germany.
If batteries were not completely empty when connected to the power, their capacity could decrease. However, this is no longer the case with today's lithium-ion or nickel-metal hydride batteries.
Myth: Don't charge your phone overnight - it can explode.
Stories about burning or exploding batteries usually come from the era of nickel-cadmium batteries.
"With the lithium-ion batteries found in today's smartphones and laptops it's practically impossible," says Matthias Baumann from German technical certification provider TUEV Rheinland.
"The protection mechanisms within the cell and the charger - whether on a phone or a laptop - will prevent overcharging."
Charging will stop automatically when the battery is full or the temperature is too high.
Myth: Only charge a new phone's battery when it's empty.
In principle this is true as the first few charges of lithium-ion batteries are the most critical.
"But this is exactly why these cycles are 3performed at the factory," says Dirk Uwe Sauer of RWTH Aachen University in Germany.
Although users don't need to worry when charging their new phone, they do need to take care not to always let the battery go from completely empty to completely full, as this can be detrimental to battery life.
"These so-called deep cycles shorten the life," says Sergei Rothermel from an electrochemical energy technology centre at the University of Muenster in Germany. "Low cycles that charge the battery from 20 to 70 per cent are optimal."
Myth: Batteries last longer when the heating is on.
On the contrary, "batteries should be stored in a cool place if possible. A rise in temperature of 10 degrees doubles the rate of aging," says Dirk Uwe Sauer.
The researcher even recommends storing batteries in the fridge, for example the laptop battery, if the laptop is usually primarily as a desktop computer and is generally plugged in.
This is best done when the battery has around 20 per cent charge left. Make sure to be allow it to reach room temperature again before the next charge.
Myth: Drain the battery completely before storing it.
In the case of lead-acid batteries, such as for cars and motorcycles, this is actually true.
For a lithium-ion battery, it is "aging fastest when it is fully charged. However, batteries should not be stored empty," says Dirk Uwe Sauer.
This is because the battery could become too empty and then won't charge up anymore.
For example it's not a good idea to store an e-bike with an empty battery over the winter.
Instead the battery should be stored with a 20 per cent charge and, if possible, the charge level checked occasionally.
Myth: Making phone calls while charging damages the battery.
Not true. Smartphones and laptops with lithium-ion batteries can be used without problems during charging.
"In contrast to the older battery technology you can charge at any time, interrupt the charging process and then recharge," says Matthias Baumann. "That does nothing to the battery."