Hi Guys,

I had one of my friends ask me this question he’s just bough his N900 very recently he wanted to know

1. If for the first time if it is necessary to charge the battery for the whole night, does that ensure a better battery performance.

2. Is it necessary to calibrate the screen on the N900 when you “ON” it for the first time and before you start using. What is the purpose of calibrate screen ?

Cheers !

The answer to both questions is "No".

Not that I'm aware of, but then battery management seems to be an arcane art for some.

Not necessary, it is calibrated by default. so you could either verify it at first or go back in and recalibrate at various points in the future once you get a feel for interacting with the screen. It's not critical at first run.

1) Not since 1990. The Li-Ion battery chemistry doesn't need any special charging. When the devide arrives, it will be between 40 and 60% charged, this is the ideal charge level. From there either use it or charge it, it makes no difference. The first time it reaches end-of-charge it will store the battery capacity, but this doesn't affect any functions. There is no loss in autonomy.

2) The function is there to correct slight manufacturing differences, slight installation differences, minor stuff that could happen during use. Standard resistive touch screen measures current when the screen is touched, this is an analogue value. As a result, the sum of all tolerances could make the screen slightly one way or the other. Re-assembly of device could slightly move the points, etc.

As a result, a calibration feature is available, so the software would correct for such tiny inconsistencies. If you find yourself clicking a tad above, below, or to the side, run calibration and the software will learn where the touch points are, correcting on the go.

One more advice. A long time ago, electronic battery management was a dream. With the advent of picocontrollers, newer batteries have internal management. Coupled with N900's exquisite battery management hardware and software, it's all automatic. As a result, don't take ANY battery tips from anyone. Any gain from minor enhancements will far outweigh bad or old practices that could cripple the battery.

In newer devices, the best way to care for your battery is do nothing. Charge as needed, discharge as needed. Try to avoid unnecessary cycles (5 5-minute charges are wore than one 25 minute charge), but don't go to extreme lengths. And, before you ask, no, battery never charges 100%, it's not a bug. It charges to less and less as battery ages. Don't go freezing it as per whatever site Google popped up. Also, charging from wall charger is faster. Over USB it can take up to 3 hours. This is normal.

For more information, the forum has a battery life thread where lengthy discussions on battery practices took place, but the short version is leave it alone and try to not discharge to nothing and forget about it for days.

So I still did not understand is calibration of screen when you "ON" the phoen for the very first time required or not ?

It's there to correct issues. If you have issues, run it. If you don't, then don't. Required? No.

FYI
Battery performance gets slightly better after 3-5 charge cycles. Something to do probably with charger chip calibrating itself.

At least I noticed after couple of first days/chargers that battery was better and IIRC there is some threads about this here TMO also.

Isn't that the reported values as opposed to actual capacity? That is, that affects what the numbers on the screen say, not the actual uptime of the device.