10-27-2016 06:31 AM
Hello guys! I have a problem with performance on battery. When battery <40 %, my laptop starts to run too much slowly. When i open Resource Montor, i inspect that CPU max frequency is limitation by 32%. I try to play with battery plan option (put 100% CPU freq) in a differrent plans, but all is not affected.
Help please. It is too hard to browse web pages in this performance... But if i plug in power supply - CPU freq immediatly increase up to 120%.
10-27-2016 08:27 AM
Hi KKozlov ,
Welcome to the Community Forums.
Similar to erratic battery behavior was a released service tip here.
Quoted from this thread :
"In response to customer reports of unexpected battery gauge behavior on Y40-70 and Y40-80 laptops, Lenovo determined the battery gauge software is performing as expected. The unusual gauge results being reported are a reflection of the battery reaching end of life.
Lenovo has released a Service TIP to assist customers with obtaining battery replacements under warranty, or if out of warranty, to find a replacement battery from Lenovo-approved vendors. The Service TIP can be found here:https://support.lenovo.com/us/en/solutions/sf16-I0
The part numbers for Y40-70/80 batteries are:
Y40 SP/A L13M4P01 7.4V48Wh 4cell bty (Y40-70/Y40-80) 121500248
Y40 LG L13L4P01 7.4V48Wh 4cell bty (Y40-70/Y40-80) 121500249 substitute part121500251
Y40 CP/C L13C4P01 7.4V48Wh 4cell bty (Y40-70/Y40-80) 121500259 substitute part121500251
To determine which battery came with your Y40 notebook, instructions for removing the bottom cover can be found in the Hardware Maintenance Manual pdf here. An alternative to opening your system (which does not void warranty) is to search for batteries using themodel/product number located on the bottom cover. "
You may call in technical support for recommendation informing the scenario and service tip.
10-27-2016 08:40 AM - edited 10-27-2016 08:42 AM
Thanks, but i dont have problems with jumping battery percentage and battery life. Battery work fine (3-4 hours) without jumping 30-0%. Discharging normally.
My question is - why below 40% battery, system automaticaly limit cpu freq. at 32% of maximum performance and how i can turn this "power safe" mode off ???!!!!
10-27-2016 09:25 AM
Hi KKozlov ,
As you have described trying the same scenario on different power options settings (high performance on both battery and AC connected) and same CPU usage , it doesn't to be erratic for now as I feel that it would be an initial event .
While you still have warranty coverage , I would suggest to have it checked by technical support as a probable emerging issue similar to this topics with different manifestations:
Notice here on this post : Y40 hibernating without giving low battery notification how the machine goes in hibernation as your CPU goes on power save mode as if not receiving needed power on lower battery range. Your machine maybe starting to have emerging symptoms and doesn't have to wait until the battery goes jumpy.
It feels like another task calling in but in such event , best to use your warranty in your advantage.
Update us how it would work best for you.
10-28-2016 01:17 AM - edited 10-28-2016 01:18 AM
Thanks. Officially this model is not supported and dont have warranty in Russia. So i try to order and change battery by myself.
Tell me please, do i need a change firmware of battery controller?