M4400 6-Cell battery dying after a year of use

You're right on time then!
Yeah i know...they can just stop from on day to another, or wear down fast, or last for years. You never know how it's going to be but indeed, not charging it when it's full and such is supposed to help things a bit.

 

In spite of Lithium-Ion batteries no long being a new technology (I bought my first notebook with this type of battery in 1996), performance still seems to be a lottery. There are many usage variables including drain and recharge current operating and charging temperature in addition to the number of charge cycles.

Dell uses at least 3 sources for batteries (Samsung, Sony and Panasonic come to mind). That should not influence the long term performance, but maybe it does. My 6 cell battery is a Samsung and has had one year of service, but has not been substantially depleted many times. When reported wear increased to 15% I did a deep discharge and recovered most of the lost capacity. It is quite likely that the modest power drain (normally 10 to 15W) of my E6400 gives the battery an easier time compared to the M4400.

John

 

I have the sony.

I tried to do a deep discharge but vista kept forcing it into hibernate eventually. I had set critical battery level at 0% hoping to disable the auto hibernate.

Does anybody know how to disable the auto hibernate feature? (I can only either standby , hibernate or shut down. I dont see the "do nothing" choice for critical level action > battery)

 

A Google for "Vista disable critical battery action" took me to this thread as the first hit.

John

 

You could always let it hibernate and then boot into the bios and keep it there to finish the draining.

 

please do NOT drain your battery if it's a Li-ion type. That memory resetting drain is applicable to Ni-Mh and Ni-cad battery but not Li-ion...it might damage the battery even further or just kill it it one go. Li-ion is not meant to be fully drained. The recalibrating mentioned on the web seems to be nothing more then lowering the amount the battery needs to reach 100%....which is completly useless ofcourse.

let's say:
battery used to have 55.000 mWh......wear is at 10% so full is now 49.500 mWh
Recalibrating sets it to see 49.500 as 100%....which is true because your battery will never get more than that but it doesn't improve anything.
So far i've never seen a trick that really recovered a battery and sorry to say John but the discharge you mentioned already halved one of mine in the past and killed a friend's so i'm not trying that again

 

If an occasional deep discharge is bad for the battery then why do many current notebooks include a battery calibration routine in the BIOS which does a full discharge / recharge cycle?

The electronics in a Li-ion battery stop the discharge at a pre-determined safe level. The discharge process is therefore not the same as with the Nickel batteries which include no electronics.

At the same time I acknowledge that a deep discharge may appear to help an already unhealthy battery to die. This may be because the recalibration quantifies the remaining capacity which is less than thought.

John

 

i was having a problem on my E6400 where my battery would suddenly drop from around 37% down to immediately 7%. I checked my battery info and there has not been any capacity lost from the 6 cell after 4-5 months.

I discharged it to 0% then charged it back to 100% ...this has seemed to fix the problem and no capacity has been lost.

I dont know how it worked, but it did.

 

If it helps great but i've never seen it recovering actual capacity, quite the opposite so i won't risk it again.
It might be though that when you don't use the battery often a recalibration works to iron out any mistakes in the electronics, also the reason why a monthly discharge or so is recommended to keep the battery in shape. If you do use the battery all the time and you lose capacity because of actual wearing down then i don't think calibration helps.

could there be a difference there?

 

Hi,

I work with these batteries in a model helicopter without security cut-off electronics, that are buid into a PC.
A Li-Ion or Li-Po battery must not be discharged under 3 Volts per Cell, that usually meen 9Volts in total. If you get below that the propability of battery-death is VERY high!

So please, do NOT deep discharge them! It only recalibrates the Energycounter, thats why you may get a better result.