N900 connected to USB at home 24/7 bad for battery?
 

The title almost says it all.
So if one keeps N900 connected to PC's USB port 24/7 when at home, does it shorten the life of the battery?

I got USB-networking working (routing, dns, other stuff...) and the connection speed is 5x what I can get with my current mobile carrier, so when N900 is doing updates, or I configure it, I'd rather keep it in USB all the time. (Using ssh and VNC to control N900 at home with PC's keyboard and mouse.)

When I kept my laptop connected to wall power output 24/7, the lithium-ion battery on it went bad very soon and I learned, it is not good to keep Lithium-* batteries connected to the charger all the time.

Re: N900 connected to USB at home 24/7 bad for battery?
 

Keeping any Lithium-* connected _all_ the time isn't such a good idea indeed, a good rule of thumb is to use up your battery (to like 5%) at least every two weeks (what I've always learned, there probably isn't such a thing as a perfect regularity when to do this).
Same goes for laptops btw ;)

Re: N900 connected to USB at home 24/7 bad for battery?
 

There could be a software fix for this, like, when connected to USB and battery has fully charged, do not start charging again until charge-level has gone down to X percent. (50% for example, value to be chosen in the program.)

Re: N900 connected to USB at home 24/7 bad for battery?
 

Exactly, why isn't it implemented yet? It would be very beneficial for laptops. Mine is constantly connected to the charger and because of that over 1 year after the purchase my battery just died. It wore out with time. It is even no longer recognised by the system (info at startup says system is unable to charge it because of it now being an 'unknown battery')! That hurts really. I cannot even disconnect for a sec without the laptop turning off just like an ordinary PC...

So the answer is obvious I should say

Re: N900 connected to USB at home 24/7 bad for battery?
 

Because then people will complain that their battery is not full when they disconnect their device from the charger.

Do what your laptop's instruction manual says: take the battery out when connected to external power for extended amount of time.

Edit: Yes I know, N900 doesn't work without battery...

Re: N900 connected to USB at home 24/7 bad for battery?
 

I haven't tried, but I think N900 won't work if battery is removed and it would still get power from USB.

I wonder if it is possible to forbid (userspace, dbus, ....) charging to start, if N900 is ON. Then software for this could be developed.

Re: N900 connected to USB at home 24/7 bad for battery?
 

I don't think so.
When the battery is full, the device uses the charger's incoming electric ONLY for the processor, backlight, etc. It doesn't charge when it is full.
If you have Battery-eye installed, you can see, how the device decharges after it is full - durin it's pluged in!

The other thing: DO NOT completly discarge the lythium-battery. It is unnecessary - turns off at 10% - and it kills it.

Some reading:
"Frequent full discharges should be avoided when possible. Instead, charge the battery more often..."
http://batteryuniversity.com/parttwo-34.htm

I hope, it was useful. Sorry about my poor english...

Re: N900 connected to USB at home 24/7 bad for battery?
 

how about a chip inside n900 that does the trick?

(yes, it exists if you trust at all the apps for battery monitoring)

Re: N900 connected to USB at home 24/7 bad for battery?
 

if you have genuine battery, there is a protection circuit inside that prevents discharging completely. also overcharge and if lithium cells start to bubble, the circuit will most probably cut the current etc and at least prevent additional damage.

that's why I don't buy batteries that doesn't have protection circuits.

Re: N900 connected to USB at home 24/7 bad for battery?
 

Well, CPU is also just a chip, or USB controller, which can be controlled from software, so it is a question just what kind of chip it is and does it have i2c-interface open.