I?m now a proud owner of a Nokia Lumia 900. I want to treat the battery right this time around. What are some steps to not only conserve battery life, but also the health of the battery in general? Is leaving it charge overnight detrimental to long term health? Things like that?
Yes and no. Storing a Li-ion battery at full charge DOES have some effect on ageing but it is highly temperature dependent. Heat is the biggest enemy of lithium-ion batteries.
Storing the battery at room temperature with a 100% charge would result in about a 20-25% capacity loss after a year (vs around 5% at 0 C and 40% at 60 C). There are several factors that help to mitigate that though. You aren't really storing it for a full year, just a few hours at a time. Also your phone doesn't really keep the battery at 100%. It charges it up to not quite full and then floats a bit. It stops charging and runs off battery until it drops a few percent and then charges it back up again. Not going to 100% like that helps to keep some of the nasty things that cause premature ageing from happening. That's also why your phone often seems to drop so quickly when you first pull it off the charger in the morning.
More frequent shallow charges will slow down ageing compared to frequent deep discharges. That is partially due to do with the fact that the battery gets warmer when charging and a deeper discharge means it gets warmer for longer.
At the same time, an occasional deep discharge to dead or near dead is good as it helps to calibrate the device's battery meter. Best way to handle it is to let your phone run down once a month or so.
Don't leave your phone in the car in warm weather, especially in direct sunlight and ESPECIALLY if you live in Phoenix or somewhere similar.
If you're going to store your battery for whatever reason, do it with around a half charge (40% is said to be ideal). Most batteries have a protection circuit that trips if the voltage drops too low (your phone will shut down before it gets to that point). If you store it for a long time with minimal charge the battery can self-discharge below that voltage and trip the circuit.
In short form:
- Don't leave your battery fully charged for months on end.
- Frequent shallow charge/discharge cycles are better than less frequent deep cycles, especially to < 25% remaining charge
- DO run it down once a month or so to keep your battery meter in prime condition.
- Don't stick your battery in the oven or leave it in the car to charge while exposed to direct sunlight.
- Don't store your battery for months with no charge. This kills the battery.