NP700Z5B-S01UB battery life terrible after reinstalling windows

I reinstalled Windows 8 and found out it had 2-3hrs battery life compared to 7. I thus downgraded, and deleted the OEM partition thinking I wouldn't need it. Now my battery life is consistantly low at 2-3hrs. I installed all the drivers and everything I could imagine with battery saving effects such as screen brightness and using power saving modes, but its still bad. Anyone know what file I'm missing and where to get it?

Reinstalled with Win8, everything is good now.

 

What CPU utilisation does Task Manager show when the CPU is on idle?

John

 

Thanks John, it was at 25%. SW manager kept crashing and restarting, I have no idea why it didn't work. I just uninstalled it and now it shows an estimate of 4hr 35min at 73%!
I feel absolutely stupid! I was doing everything but looking at the task manager and figuring out what was gobbling up so much battery life.

Is that considered acceptable? I thought it would be closer to 5hr. Do I need to recalibrate the battery and if I were to do I have to charge it up from the top?

 

You may well find that the battery time improves after a few days when Windows settles down. People say that Win 8 is capable of being more power-efficient than Win 7 but I don't have any first-hand experience of Win 8. The reported run time also fluctuates significantly depending on usage - it seems to be calculated for each 1% discharge step. I look at the actual power drain using HWiNFO and do some simple arithmetic. If, for example, there is 40 WHr capacity remaining and the power drain is 8W then that indicates 5 hours. Except that once the charge remaining gets below about 5% Windows will be wanting to go to bed.

If you want to check the battery calibration then use the option in the BIOS. I think the starting charge level doesn't matter-the calibration just drains the battery until empty and resets the gauge then measures the charge to fill it up.

John

 

I still feel like the laptop has worst battery life even though I disabled aero and all have it running very lean..

Do you know what else could be causing my battery life to be worst?

 

Some initial thoughts:

1. Is the CPU utilisation on idle not more than the 1% to 2% range?
2. Is Unutilised hardware powering down if not busy?
3. Is you display brightness near to minimum?

In past times Flash running in a web browser was a power guzzler but this may have now improved. Bluetooth can also take power, even if not connected, because it (and WiFi) periodically search for other devices.

John

 

My battery life still reports at 3 hours at best with the battery extension on, If 100% should be 8 hours, then 80% should be like 6 hours right?

It did this after I did a restore. I had it on a medium brightness I think when it reported 8 hours, and even at low, it reports about the same for some reason.

Any other idea what it could be? Could not having the SSD in working condition do it?

CPU reads as low.

 

We have got to get a bit more scientific. The Windows estimate of time remaining is updated for each 1% of drop in charge so is strongly influenced by the power usage during that period. However, for uniform operating conditions it normally provides a reasonable estimate except it doesn't allow for Windows automatically shutting down the computer with several percent remaining in the battery.

Here is my first suggestion:
Install and run HWiNFO. What wear does it show under the battery properties? Then pull out the mains power and open up the Sensors tab, look at the battery data at the bottom of the list and see what the power drain (it is the Charge rate entry, but -) is. It shows the max, min and current rates. The lower the numbers the better. It is then easy to see, for example, the effect of screen brightness on power consumption. From the battery drain and battery capacity you can estimate the run time (= battery capacity in Watt-hours / battery drain in Watts).

As I noted previously, the battery drain rate is very sensitive to what you are doing. Lowest drain rates will occur if you are doing an undemanding task such as editing a document in Word with a dim screen, other programs such as web browsers closed and WiFi / Bluetooth turned off (Fn+F12). Having HWiNFO running creates some extra power consumption because of checking all the sensors. Under the optimum power saving conditions I can get my NP900X4C down to about 6W power drain.

If your actual run time is significantly less than predicted then it is time to do a battery calibration (there is an option to do this in the BIOS). This involves fully draining the battery and then fully charging it (so best to turn off the battery life extender). The calibration enables the actual battery capacity to be recalculated. After doing that recheck the battery wear in HWiNFO.

John

 

Thank you very much John. I ran HWiNFO and it registers strangely, the min is much larger than the max, which I find very strange.

Mine registers at 22w or at best 18w draining. Can I calibrate it when its close to empty or is it not recommended?

Is there a way to downclock the CPU? It usually uses 7w but I can't find options in power settings for downclocking.

 

That's because HWiNFO calls it the charge rate, but battery drain is negative. The smallest number is the minimum value.

18W as the minimum discharge is very high and explains a lot.

Does the HWiNFO CPU speed display show 800MHz or higher? 800MHz is the lowest it can go but power saving is implemented by the use of Sleep States (see here).

Some further thoughts:
1. What power profile are you using? Look in (Easy) Settings. The Samsung Optimized profile is the best overall. If you have the High Performance profile selected then the CPU won't go to sleep.
2. Is the graphics Intel-only or Intel + another GPU?
3. Have you anything connected to the USB ports? They can use power (but unlikely to be 10W).

John

 

Thank you so much, you're extremely helpful.

This model uses switchable graphics using Intel and ATI.
I am using Samsung optimized profile. Is there a way to know which GPU is running? I set it to always maximize battery life in both the ATI and the Intel GPU portion in power settings.I disconnected all USB ports at the time of the test.

I just tried disabling ATI, and then using the Intel, it shows it using minimum of 20W. The CPU is clocked at 2195.3Mhz-798.3Mhz.

I'm going to look into the Bios...

 

I find 20W consumption high even if the ATI GPU is running under light usage. Since the problem has persisted through a system restore (was that a full restoration of the factory image using Samsung Recovery Solution) the BIOS is worth checking for power-related settings, particularly CPU and GPU. If you can't get down to 10W or below under very usage then we may have to suspect a hardware problem. Are you still in warranty?

John

 

Yeah, I am, I deleted the partition like an idiot though. I'm gonna call them about it.
There aren't that many options under the BIOS otherwise I'd have messed around more with them.

 

I'm puzzled why Samsung don't provide a nagging utility to get people to make a backup of the factory image onto an external device.

Did you ever check for any BIOS updates. See here for a link to the BIOS Update utility. It might fix the problem and it's something that Samsung support might ask you to do.

Another test would be to boot from a Linux live CD and see how quickly that drains the battery. Tweaking Linux for best power efficiency isn't easy but if you see power consumption that is lower than what you are seeing in Windows then it suggests something wrong with your Windows / software.

John

 

I know this is an old thread, but in case anyone is reading through and got the same problem, try reinstalling windows. I think my install was messed up, I reinstalled with Win8 and my battery life is phenomenal.

Might have been a bad install or a driver issue love the laptop now.

 

Hi John- I was noticing reduced battery life in windows 8.1 vs. 8.0, but then the bad battery life followed me to windows 8.0 and I knew something was up. I installed HWinfo, and the battery ware was showing as 25 percent- 60Wh down from 80. Is there anyway I can reverse this?
Thanks,
Xenon

 

Run the battery calibration utility in the BIOS.

I suggest the following procedure: Make sure that Battery Life Extender is turned off; Run the computer on battery until it shuts down; plug in the mains power, start the computer and go into the BIOS (tap the F2 key a few times immediately after pressing the power button); Find the Battery Calibration option in the BIOS, pull out the mains plug and then start the calibration. The computer will then run until the battery is completely empty (Windows always shuts down the computer with a few per cent charge remaining - you might see the computer run for 5 minutes or more on 0%); Once the computer has shut down then plug in the mains power and let if fully charge then recheck the battery properties.

However, 25% wear on a two year old battery might be realistic depending on usage, particularly if the battery has been discharged / charged on a daily basis. If maximum run time is important then the battery part number is BA43-00318A which you can put into your favorite search engine to find sources such as this. Officially, the battery is not a user-replaceable part because it involves removing the bottom of the computer but it is not difficult to do the swap.

John

 

Thanks, John-- I'll keep that part number written down somewhere. It's disappointing to me that batteries wear out so fast, but I guess that's the nature of technology-- yes, I have been taking my laptop to school every day and running it to 10% or less for the last year or so. I'll try recalibrating, see if it helps any
Xenon