Why does a fully charged battery last for a different length of time depending on how it's charged?
August 18, 2010 3:15 AM Subscribe
When I charge my phone using a portable charger, the battery runs out quicker than if it's charged from the mains. Why is this?
I have an HTC Hero phone, which I normally charge from the mains. Occasionally, I'm away from a mains supply for a while so I use a Powermonkey portable charger to charge my phone.
When I charge my phone to 100% using the Powermonkey, it runs out significantly quicker than if I'd charged it form the mains.
I thought this might have been down to a different usage pattern when I'm out and about, but after a couple of tests that doesn't seem the be the case. It seems like it should just take more time to charge when it's coming form a weaker source, but I don't know much about the chemistry inside a rechargeable battery to work why this is happening.
Can anyone help fill the gaps in my understanding here?
I have an HTC Hero phone, which I normally charge from the mains. Occasionally, I'm away from a mains supply for a while so I use a Powermonkey portable charger to charge my phone.
When I charge my phone to 100% using the Powermonkey, it runs out significantly quicker than if I'd charged it form the mains.
I thought this might have been down to a different usage pattern when I'm out and about, but after a couple of tests that doesn't seem the be the case. It seems like it should just take more time to charge when it's coming form a weaker source, but I don't know much about the chemistry inside a rechargeable battery to work why this is happening.
Can anyone help fill the gaps in my understanding here?
Fwiw, I have the same issue with my phones here in the States. It does not matter how long I charge with the portable (or non oem replacement charger) it still lasts much shorter.
posted by JohnnyGunn at 7:11 AM on August 18, 2010
posted by JohnnyGunn at 7:11 AM on August 18, 2010
Some cell phone battery meters are unreliable, though I'm unsure if the Hero has that problem.
Perhaps charging it to 100% with both methods, then unplugging and timing how long it takes to read as 75% or summat might hold a clue?
posted by sary at 7:13 AM on August 18, 2010
Perhaps charging it to 100% with both methods, then unplugging and timing how long it takes to read as 75% or summat might hold a clue?
posted by sary at 7:13 AM on August 18, 2010
My cell will register "completely charged, thanks!" after ten minutes of charging. It doesn't appear to have any correlation with actual charge level.
posted by Civil_Disobedient at 9:14 AM on August 18, 2010
posted by Civil_Disobedient at 9:14 AM on August 18, 2010
This thread is closed to new comments.
In this case the phone is probably displaying "100% charged" at the end of main charge cycle rather than at the end of the top-up trickle charging which brings Li-Ion/Poly batteries to their full capacity but can take significantly longer.
posted by Morbuto at 4:03 AM on August 18, 2010