Laptop Battery Life - Try This!

seriousrikk

seriousrikk

Messages
5,881
Name
Richard
Edit My Images
Yes
Right, long and short of it is my laptop battery life was getting a bit low and it seemed to charge a bit quicker than I remember.

So I decided to run it flat - and I mean properly flat. To do this I have disabled the 'Critical battery' setting in windows which puts the machine in standby when it reaches 3%

I have now been working for the last half hour with the battery flicking between 2% & 3% and 3 minutes remaining.

From what I understand batteries that provide specific detail about their remaining capacity to the computer get muddled up about how much capacity they have and occasionally these meters benefit from a reset. Some manufacturers provide a tool for this others don't - and fully discharging and recharging the battery often will sort it out.

This is more of a FYI post - if you've got laptop battery issues - try flattening it properly rather than just charging when windows tell you to.
 
neil_g said:
here we go with this can-o-worms ;)

for the record you shouldnt totally discharge li-ion's as it trashes them, but i dont think when windows says its critical it means its totally flat..
Click to expand...

+1
 
yes these are now used in racing radio controlled cars and the speed controllers are programmed not to allow the batteries to go totally flat because it does ruin them............
 
I'm pretty sure there is a KB article on the Apple website suggesting something along these lines to calibrate the battery meter.
 
hmmm everyone has a different opinion on this matter I think

My advice (as an experienced systems engineer) would be to run the battery as low as possible every time before recharging it. 5% would be the lowest I would go.

Also dont leave the battery in when the machine is plugged into the mains
 
In my experience if a battery goes total flat and is then recharged it can go reverse polaraty is + can become - i had this happen to me some years back when i was a radio ham. This can be sorted by zaping them on a old charged car battery but can cause you to get burnt and hurt and the battyer could explode . The battery being zaped must be a vented cell ie must have a pinprick hole at the + end of the cell. This will return the cell to the corect + to - and then will recharge ok.
WARNING
But this is not a recomended method so if you try it and get hurt dont blame me
 
noneforit said:
Also dont leave the battery in when the machine is plugged into the mains
Click to expand...
most charging circuits are clever enough to turn off when a battery gets to max charge. therefore this point is moot.

J.R.Abbott said:
In my experience if a battery goes total flat and is then recharged it can go reverse polaraty is + can become - i had this happen to me some years back when i was a radio ham. This can be sorted by zaping them on a old charged car battery but can cause you to get burnt and hurt and the battyer could explode . The battery being zaped must be a vented cell ie must have a pinprick hole at the + end of the cell. This will return the cell to the corect + to - and then will recharge ok.
WARNING
But this is not a recomended method so if you try it and get hurt dont blame me
Click to expand...
whoa whoa whoa... maybe for NiCAD's and NiMH's (shorting them out "reset" their memory) but bloody hell - talk about a piece of advice that's likely to kill someone !
 
I seem to remember reading that NMH batteries won't always charge if they are totally flat, something to do with the charger needing some battery voltage to recognise the battery? If I remember rightly the trick was to put a little bit of charge back in with a 9v battery. NOTE I haven't tried this and don't recomend it!
 
we used to stick old batteries that only lasted 10 minutes on a full charge in a bag then put them in the freezer for about 10 minutes.

those were the days. LiIon, however, doesn't need any of this stuff. the Apple "discharge it" thing is until the laptop turns off, which is usually at about 3-5%. all the OS then does is take the 100-3-5% and make it 100-0% (with 3-5% reserve) by adjusting it's output readings by 3-5%.

dont run liions down to death, cos that's what they'll end up with.
 
with my old Dell laptop you could go into the bios and recondition the battery.it took a good hour and deep cycled the battery twice and recalibrated the meter. IIRC i had the laptop about 4 years and the battery wasn't far off as good as new when i sold it.

my current vaio doesnt have this feature, but i bet there are lots out there that do.
 
We've had this debate recently :)

The biggest killer of Li-ion batteries is being flat. That is why your computer will shut down well before this actual state. Li-ion batteries lose charge naturally just whilst sat there so if you leave one to go to this near flat state and then don't charge it it will eventually lose all its power and be at risk.

Another problem are that some poorly designed charge circuits can over charge or over heat the battery and this can also reduce its life.

You do not need to let them run down and recharge them or do full cycles of charging or anything like that. If you have a well designed and working laptop there is nothing to gain by removing the battery whilst it is on the mains (as a correctly designed and working charge circuit will stop charging the battery when it is full)! In fact you can't do this with ANY new Apple laptops as they all now have captive batteries. I am typing this on a macbook pro that is showing a health state of 94% (ie 94% of new), it is 2 years old, it has done 560 complete battery cycles and runs my laptop for upto 3 hours or so between charges. Is it used both connected and disconnected.

There are lots of silly myths over batteries using information about previous generations of battery.
 
LI-on batteries work best if top up charged regularly and should not be allowed to go flat. Ni-Cd batteries should be discharged every once in a while to avoid the memory effect that they are prone to.
 
Surely the best thing to do is to consult the information from your laptop manufacturer relating to your specific laptop?
 
i actually like the apple advice (i think i may have to go and have a lay down), personally ive found that even the li-ions ive had seem to eventually degrade if left on mains for 99% of the time and that regular running down (NOT TOTALLY FLAT) until windows says to plug back in helps.

i know li-ion dont have a memory effect, its just what seems to happen over time if left on mains for extended periods the battery charge seems to drop.
 
neil_g said:
here we go with this can-o-worms ;)

for the record you shouldnt totally discharge li-ion's as it trashes them, but i dont think when windows says its critical it means its totally flat..
Click to expand...

Yep, if they drop below a certain voltage they can be damaged, and explode (or usually just puff out)
 
You must log in or register to reply here.
Back
Top