Should I drain the battery?

New M11XR2 owner here. I've been letting the battery drain to 10% and just one time tried to drain it down below that to about 5%.
What is best for creating longevity for the battery and maintaining a long 5 1/2 to 6 hour battery life on the m11xr2?
Does anybody really know?

 

For the M11x's battery (which is a lithium ion I believe) should never be fully discharged. Also keeping it on a/c power all the time is perfectly fine.

 

It's true ideally the battery should never be brought low because it reduces the capacity, but it is usually recommended every 30 or so discharges to run it out of battery because partial discharges cause the capacity reading to become less accurate, and that is fixed by depleting the battery completely. Doing it that infrequently won't affect noticeably the capacity.

 

fully discharge only applies to lead acid batteries and ni-cad. the reason is to establish charge memory of the electrolytes of the battery cells.

 

Thanks for the info.

I noticed after I drained to 5%, I got less battery life and the Windows remaining battery life went all to h*ll. It now sometimes says it has 131 hour and 10 remaining or switches within a few minutes from 3 hours remaining to 5 hours remaining.

 

I did a full discharge, and my batterybar reading on battery capacity dropped by 2k mWh.

 

A Li-ion battery should ideally never be discharged that low. LiIon batteries are happiest at 40% charge, stored in a dark, cool, dry place. Heavy charge/discharge cycles and heat are the two worst enemies of LiIon batteries.

If you absolutely want the longest possible life on the battery, then keep it at 40% capacity. Then turn off the charging capability by going into the BIOS, and setting "Charger Behavior" setting to Disabled. When your laptop is plugged into the AC power adapter, it will run off of power, but not charge the battery.

When you are about to go on a trip where you know you will need battery power, then go into BIOS, change the setting back, and charge your battery to 100% before you leave.

Li-ion batteries should typically never be fully discharged. However, it is good to fully discharge them once every 30 or 40 power cycles to calibrate the battery meter.

And keeping it on A/C power all the time is the worst possible thing you can do to your battery. What you're essentially doing is constantly charging your battery every time there is even the slightest discharge - and batteries will slightly discharge just by sitting there. If you keep your battery on A/C power all the time, you can expect your battery capacity to be around 50% - 75% of max capacity after about 1.5 to 2.0 years.

It is good to fully discharge Li-ion batteries once every 30 or 40 power cycles to calibrate the battery meter. You are correct that it has nothing to do with the Li-ion battery itself. You do this for the battery meter, that detects remaining charge capacity, and determines how much to charge the battery when it needs charging.

The way that Windows battery meter works is that it estimates the remaining battery life based on your current level of power draw. And it updates that remaining power measurement once every 60 seconds or so.

So, when you're bouncing back-and-forth between 3-5 hours remaining because in one moment, you are doing something intensive on your laptop that drains a lot of power. You would typically get 3 hours of life if you continued doing that. The next moment, you're doing something less intensive, and draw less power. You would typically get 5 hours of life if you continued doing that.

The readings are spot readings at a given moment. They are not average-over-time readings, so it is perfectly normal for the reading to bounce back and forth as you're doing many different things with your laptop.

 

I may be wrong, and you may rebute, but I believe this to be false. The way I understand it, once plugged in, the battery charges up to nearly full (between98%-99%) once it hits this "full" mark, the M11 mearly runs off the A/C forgoing battery charging all together. While everything you said is correct typically, I believe this to be a feature of the M11x.

 

You are correct that a device that has a Li-ion battery will charge to full, then stop charging. All devices with a Li-ion battery will do this. It is not unique to the M11x.

However, a fully charged Li-Ion battery will slowly lose charge over time, even if it is just sitting there running off of AC power. When that happens, the charging circuit will kick in, and fill the battery back up to 100% charge.

This is one of the worst things you can do for the battery. You end up charging the battery relatively frequently this way because of the trickling loss of battery power, you keep the battery at 100% (which Li-8on batteries do not like to be at), and you increase the heat applied to the battery. Over time, a Li-Ion battery that has been treated thos way will only store 50%-75% of its original charge after about 18 to 24 months. The way to avoid this in most laptops is to remove the battery when you are plugged into AC. On the M11x, you have the option to disable the batter charging behavior in the BIOS.

 

FWIW, I never remove the battery from my laptops. My 17x is now a year old and almost always plugged in 24x7 and on the rare occasion I do go mobile with it, I have not noticed any reduced batt time.

Its not going to drain while plugged in. Your batt is under warranty for a year. Don't worry about it. IMO of course

As a couple of other posts mentioned, its the # of complete discharges which will kill your batt. I learned this lesson with my Dell E1705. As I understand it, after about 300 complete drain/charge cycles you are dead in the water.

 

Just want to share with you folks my experience. Mine is the R1? It's the C2D 7300 and not the SDD so...I am not sure if this is the same battery as you folks' R2.

I bought it in January. I don't use it very frequently. I guess up til now I have been using it for a total time of 2 months...what I did was I let the battery go flat, about 10 times I have been doing that. Then re-charge it. The only few occasions that I have had it charged while using it were when the guy installed the system brand new in the retail shop for me, then when i was restoring it from Dell Safe Backup.

In the last couple of days, I have been trying out the BIOS "Battery Charging" option, set it to disable and then plug in the power and light the system up for some HD online video playing. Just now I have checked it out with the BatteryBar. It says "1.8% of 64,530mWh" as the Battery Wear. So I have lost about 1,162 mWh so far. Regretably BatteryBar doesn't tell me the number of hours the battery runs for.

I guess if I keep the power A/C plugged in while using it I might lose more.

 

I sometimes drain mine down to 60-40% as I usually run from the wall outlet. I've had mine since May with no troubles

 

I just got my M11xR1...
I drained it once to 5% and that is all I've use battery for. Was it bad to drain it to first time now? Is this unnecessary?
I think next semester I will old use it 3-4 times a week ( I would assume non- fully discharge rates).
Can I expect my battery to last good for at least 2 years? I enjoy having the ~6-7 hours battery life.

Also I pressed the function key and the battery icon for f2, but it will only say battery enabled... Is there something wrong here?

 

You will lose capacity over time... but your charging/discharging behaviour can dictate the rate of this loss, so you can exert some measure of control over this process. I recommend reading this article.

 

In the little alienware booklet under tips and tricks I think it says to drain your battery once when you get it but I cant remember. For the record thats what I did (once) and have had no problems.

 

IIRC, occasional full draining is recommended to recalibrate the battery meters. The article linked above suggests every 30 cycles.

 

I have 2 months with mine, is with A/C 95% of the time, I think I have used it on battery 5-6 times only, I have 0.0% of wear in battery bar...

I did the cycle with my 2 year old Dell Inspiron, the charge it, then drain it to 10%, then charge it, etc. It has now 72% of wear, and it last like 25min in battery, I´m gonna keep the m11x plugged the most time I can, and sometimes use it in battery...

Also, is gonna last less and less over the time, no matter what you do to it, even if you remove it and never use it again brand new, but you want to start to see it over a year of constant use, not months....

 

The lowest I've drained is about 20% from what BatteryBar says. If it's 90%-100% then I'll just disable charging in the BIOS and go from there.

 

So, would it be better to use battery and not let it fall below 30-40%? Then plug it in and charge while using it?

Next semester I have class 2 days a week, but all day. I have an hour break at lunch. If I have it down to say 70% by then, charge it up to 90% while eating lunch then drain it down to 40% for the rest of the day.

This would be better than draining it to 10-20% those 2 days?

 

If you're actually going to be using your battery, then just use it and don't worry about charge levels. In the end, the inconvenience of having to manage your battery usage pattern is a greater burden than whatever extra wear-and-tear there might be on your battery.

Keeping a LiIon battery at 40% is only for long-term storage of batteries (e.g. at least weeks on end). The reason is that a LiIon battery at 100% charge degrades battery life.

This does not apply to you. Your battery was meant to be used. Use it, and don't worry about micro-managing your usage pattern.