M1330 Always PLugged in to charge or use Battery?

hi,

I have a dell M1330 the person who installed it says not to leave the charger in the laptop all the time instead disconnect it once it is charged.

i thought the life of the battery was increased when u leave it on the AC adapter all the time as using the battery would discharge it and cause the battery life to drop. he claimed the battery would continue to charge after reaching 100% and cause it to heat up.

Your Thoughts on the issue

 

Advantages to leaving battery in while plugged in: Less Hassle, battery acts as uninterruptible power supply, battery is always fully charged for portable use.

Disadvantage: The battery might die more quickly because the laptop applies a constant "top off" to replace the slow self-discharge. It is unlikely to heat the battery up much because of the small charging current, but the charging current puts some stress on the battery that could shorten it's life. How much is anyone's guess.

I leave the battery in.

 

Everything Theory As of Now as tmorrowus said leave the battery in it

 

Nah, I call shenanigans on that. Surely charging discharging the battery all the time will place the largest strain on the battery?

If you have a good memory and will remember to put the battery back when you need to use it, unplug the battery and leave the power cable connected. I've found that this gives me best battery life by a long shot, but unplugging and hearing it power off completely when you were expecting it to go onto battery power is infuriating, and the cause of many swear words.

 

are you sure he wasn't talking about when the laptop isn't in use?

having the charger connected to your laptop while it is off means the transformer is constantly using electricity, which goes to waste if your laptop battery is at 100% capacity, and it's likely that having the charger trying to charge a full battery 12 hours of each day while you sleep won't do it much good either.

once you finish using it, plug it in, let it charge, after a couple of hours (or when you know it is 100% charged, which could simpley be 15 minutes or so if you're always on AC power, the charge-checker on certain batteries can be handy here), unplug it (aka, unplug the charger from the wall), that way, charger isn't wasting electricity, and you aren't putting your laptop battery at risk of some sort of overcharge damage, plus it won't blow up if you have some sort of freak power surge.

as for when it's being used? i have it plugged in, that way if i want to move about or go on battery power for 20 minutes or so i know it's already 100% and ready to go without needing to charge / power down / interrupt what i'm doing.

 

what about total Charge and Discharge Cycles which ultimately decides batt life?

 

I had a toshiba with the battery always in, and after a year of usage, the battery life dropped to about 23min (yeah, no kidding, less than half an hour) from the original 2hr and 3min. Thus, for my new dell, I use the batt when I really need to, and for the rest of the time, I keep it half charged(to prevent internal cells from reacting with each other when the battery sits idle with a full/empty charge).

Battery dies with 300 charge cycles, so the more time you plug your batt in your laptop, the faster it will meet the 300 cycles, thus killing your batt in the process (and batteries ain't cheap!).

 

No Problem when the Batt is left outside then

 

There's a breadth of knowledge that's not represented here:

Li-ion chemistry.

With regards to li-ion chemistry, it's not all about discharge/charge cycles ... much is about the actual age of the chemisty itself. That's why you see manufacturing dates for li-ion ... something that batt mfg'ers don't advertise that fact because there's nothing beneficial for them to do so.

Anyways, from a chem perspective, always top off your li-ion. Never run it down all the way or even half way for no reason, it will degrade your li-ion chemistry and thus your batt life overall.

The real question is this:

to what competency is the charging system for the li-ion batts that come with notebooks?

To that end, I am not fully qualified to answer. There will be usually voltage shut-off typically at 4.2V/cell termination ... all I will say is that I leave my battery in for reasons of convenience etc. The heat and aging will kill off my batt eventually anyways. I'll just get a replacement. More likely, i'll get a replacement laptop by that time.

For more reading check out:

http://batteryuniversity.com/parttwo-38.htm

specifically on laptops.

 

My system is always connected to the mains, and I use my battery as a UPS. I dont think it does any harm to the battery at all.
My work laptop is also plugged in all the time, and Ive had that for several years. WHen I do disconnect it, I notice no difference with the battery life. It still goes strong.

 

i keep my old laptop plugged in all the time and battery life is now atrocious

granted, the laptop is also 6 years old