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Inspiron 11 3148 BIOS - No Effect of Battery Charge Profile Changes
Hi:
First ever post on the forum -- that's because my Dell 2in1 (Inspiron 11 3148) has been a wonderful machine for me!
But I would like to change the battery charge profile to limit charging to ~80% max capacity. The BIOS does have seem to have an option to do this. I have read that not charging to full can greatly increase the lifespan of a Li-Ion battery. And I generally need only a few hours of run time. However, choosing the primarily AC option (in the BIOS menu) looks to have no effect when I later check the battery monitor icon on my taskbar. Shows 100% charge. Also using the "custom" option in the BIOS battery menu, I have set max charge at 80% and start charging at 75%. I then used my laptop without the charger down to 40% battery remaining. Then charged. Again the icon showed 100% charge (>7hrs run-time remaining). Therefore, the BIOS settings seem to have no effect.
My other laptop (a Toshiba) has a special "desktop use" utility (in Windows-not BIOS) for mostly AC mode which I am always doing with that computer. When I activated this utility, the battery icon on the Toshiba always does shows charge state at 80%.
Back to my Dell -- How do I change the charge profile?
Many thanks for ideas/solutions.
rardi
rardi
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May 12th, 2015 10:00
"Problem" is resolved. Last night on a whim, I went into BIOS again and changed the stop charge to 70% and resume charge at 60%. Plugged in the charge adaptor. This morning the task bar icon showed exactly 70%. Then I changed the BIOS field again to 80% and 70%. The icon is now showing 80% charge and not climbing. Why my first attempt didn't "take", I don't know.
deathgod
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June 8th, 2015 15:00
I'm glad it worked for you but it never worked on my laptop, Inspiron 3148.
I first switched to custom settings stop charging at 70% and start charging at 60%, F10 save and exit.
I let the battery drain til 30%, charged it but shows 100% fully charged.
I changed the settings again to stop charging at 80% and start charging at 70% but same issue happens.
How did you do it? Is the AC adapter plugged in or not when you changed the settings?
Thanks,
rardi
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June 8th, 2015 20:00
What I discovered subsequent to my previous "success" post is if the charging takes place when the computer is fully shut down, then the battery charges to 100% irrespective of my BIOS limit setting.
But if the computer is still on or in sleep mode, then the battery only charges to the max limit that I specified in the BIOS. In my case 80%. So for instance, if I use the computer without the charger and drain the battery down to say 40% -- as reported by the charge monitor icon-- and then I put the computer into sleep mode (or simply close the lid) then plug in the charger, the charging will stop at exactly 80% battery level.
kirkd
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June 9th, 2015 18:00
Makes sense, as when the computer is off, the BIOS can control nothing/
I don't put any faith in the partial charging nonsense. I have never seen any real data supporting this. My laptops are always plugged in, charging when needed, and only off charge for several months when on vacation. I am on my second battery on my 8 year old XPS M1530 and third on my 9 year old E1705. Both batteries (third party $20-25, not Dell replacements) are still working great.
rardi
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June 9th, 2015 21:00
I first started reading 7-8 years ago in technical publications about the advantages of not keeping lithium ion and LIPO batteries fully charged. This information was of primary interest for the expensive LIPO packs used for my model airplane hobby. Yes, right before the flight, charge to 100% (~4.2v per cell). But between weekends, every recommendation is to discharge the pack to the nominal voltage of 3.7v per cell. The more high-end expensive hobbyist smart chargers actually have a mode that will discharge each cell in a battery pack to a user specified voltage for storage. Or will charge each cell to a user set maximum rather than the ~4.2v default. Also when buying a lithium ion battery pack for drones or model airplanes, they always arrive with 3.7v per cell.
Same 3.7v is manufacturer's storage voltage when opening the package of a tablet or cell phone. That's why the first task is to charge up the battery.
Going back to the model airplane example, some people don't charge the pack to 100%. Instead to say 80-90%. They claim that the trade-off of a couple of minutes less run-time per flight is more than offset by the many more flights each battery pack will last when it isn't put under max performance stress. My Inspiron 3148 is good for 5+ hours at 80% charge. I don't need the 7 hours or so that a 100% charge affords. I can't see a downside to limit the charge. My other computer, a Toshiba laptop, has a "primarily always plugged in "desktop" charging utility app. My Toshiba is plugged in 100% of the time. The charge indicator is always between 60 and 70%.
More recently I have read the same about tablets and smart phones. Not charging to 100% would increase the lifespan of the internal Li-Ion battery (which aren't replaceable in many models). But in the case of smart phones, most possible hours of run-time is more important than a few more years (or more duty cycles) of battery life. So the charging algorithm dictates 100%.
kirkd
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June 9th, 2015 22:00
I have seen these recommendations before, but never any DATA, only recommendations. I am a PhD chemist, and only go by data, not intuition and guess work.
Many recommend storage at less than full charge. I have laptop and power tool lithium batteries that hold their full charge for 4 months. I use BattStat to determine the actual wattage available at full charge. Maximum charge drops very slowly for me, except when a deep discharge occurs. For best life, discharge should not go below 35%. Lithium auto batteries are not allowed to go below 35-50% for max life, and kept fully charged when possible. These batteries are warranteed for 100,000 miles.
I read some posts where batteries are charged to either full or below full, used on battery even when an outlet is available and then recharged. As the number lifetime of charged is limited, this is a poor procedure.