How discharging and recharging batteries effects lifetime

[puhlonker]

i saw in car batteries in electric vehicles one can get more cycles (discharging them and recharging them) if one does not discharge it all the way. ie, its better to charge often even when it does not need them. but i had heard that for my phone battery it was better leave it charge all the way done before charging it and always charge it to the max and that would allow for a longer lifetime. what's the straightdope on this does anyone know?

 

[Xarren]

Regarding batteries, when it comes to nimh batteries (used in cars), and others, the problem is that they are really just stacks of lower voltage cells. Problems occur because of natural variations in the cells, so if one in the middle of the stack runs dry before the others, it may cause a reverse current to run through it, damaging the whole lot. This is also why you get warnings on devices not to mix used batteries with new ones.

Most sophisticated electronics devices have a safety shut off below a certain charge level in order to avoid this problem, this will include your phone.