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my laptop with windows 7 looses battery when turned off, how can i stop this

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  • Windows 7
  • Laptops
Last response: in Laptop General Discussion
September 6, 2014 4:37:55 AM

I have a fujitsu a series with windows 7 and since i bout it last year it uses battery when turned off. so after a day of no use it is completely flat. how can i stop this?

More about : laptop windows looses battery turned stop

Best solution

September 10, 2014 12:55:39 AM

Hi, first make sure you really have turned it off. Standby still consumes power, hibernation does not.
Any lights must be off, no heat must be produced.
There are several possible reasons for this behavior.

My suggestions:
1) Check the battery gauge in percents, do not only check the most likely green lamp being turned on. It means nothing, at least with my laptop here and others i know.
2) Take the battery out of the laptop with full battery and check again after a day. Turn it on immediately after insertion of the battery and check the gauge. If it is still 100% then your laptop is the problem as it is consuming power while it should not. I havent seen such behavior up to now.
3) Assuming after that day the battery is as flat as it was before when it was inserted into the laptop. Then one reason for that could be that the cells (or a few of them) are bad and self discharge. That is a very well known behavior, the only surprising thing is that the rate of discharge you mention is quite high.
4) Everything is OK except for the battery controller in your laptop. As i have a Fujitsu laptop here myself and also have a battery problem i cann assure to you that this is possible. The battery controller in my laptop assumes a self discharge rate which is too high and indicates a charge which is way too low after a while. It does not even let me discharge the battery anymore then though it is full! Most likely you don't have the instruments to check this but you would have to measure this with a volt meter after opening the battery pack. Alternatively check the software "BatteryMon" which shows you the battery voltage, not only percents as for example Windows does. In my case i have 3 cells in series in my battery pack with a charge to discharge range of 4.2 Volts to 3.6V (standard value for LiIon battery cells) = 12.6 Volts to 10.8 Volts in total.
Now this Seiko Nomura S-8254 / S8254 battery controller inside my battery pack is just an incredible piece of crap which does not understand that a LiIon battery cell at 4.2V is always full and never 0%.
5) I know some faulty battery packs which charge within seconds to 100%. It might be that yours is broken and the batteries do not hold a reasonable charge anymore. You should be able to see this again by the battery voltage. If it rises to it's upper end way too fast or does not rise at all and stays at the lower end while the gauge goes up to 100% then your battery is most likey dead. As LiIon cells must not be discharged below something lower than 3.6V your battery is dead if e.g. you read less or equal 8.4V with 3 cells in series, 12.6V with 4 cells in series etc. etc. which indicates that one cell is electrically just missing (=0 Volt)

How do you find out how many batterie cells you have in series in your battery? There is some voltage inscripted on your battery (hopefully...). It should be possible to divide this by 3.6V. With Fujitsu i see on my battery pack they assume a voltage of 3.7V close to the lower end for the inscription on the pack. With HP i see they give the lower end battery voltage of 3.6V (Acer also), try to divide by this number as well. The number you get is the number of cells in series.

So now i am interested to hear what you find out.
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