SZ* battery fully charged and still charging - revisited

I know that this subject has been discussed here several times over, but I thought I'd share my own experiences and insight:

I don't know anything about li-ion batteries other than they are rechargable, they wear out after many cycles, and they tend to be expensive.

On the other hand, I'm a software engineer so I'm not completely clueless...

Any other notebook (not sony) that I've seen will change the battery status from "charging" to "AC Power" when the battery charge is full. My understanding of ACPI is that the hardware (and BIOS) tells ACPI that the current being applied to the battery is now at "0"mW, and this is how windows determines the difference between "charging" and "AC Power." You can see this in action with a tool that displays the information such as Notebook Hardware Control.

For example, my battery is currently charged to 57720mWh out of a full capacity of 57720mWh. However, the hardware is ALSO reporting that the battery is currently being charged at the rate of 0.087 W (that might need to be mW.) When the battery is at less than 100%, the charge rate is much higher. When the AC is unplugged, the 'charge rate' is negative (and usually reflects the power being drawn from the battery.)

So, all that being said, there are two possible explanations to whats going on:

1) Sony is trickle charging these batteries even after they are full. If this is the case, it would explain why the battery is EXTREMELY hot when running under AC power all day long (when the battery started the day at near 100%.) My understanding of li-ion technology is that this is very unhealthy for the battery and can shorten it's lifespan. It's hard for me to believe that a company such as sony - with all their consumer electronics experience - could foul something like this up so badly.

2) The problem is with the hardware (BIOS) giving the wrong information to the ACPI tables. This could be something as simple as a rounding error. If this is the case, it should be fixable with a BIOS update. On the other hand, it seems that most models of Sony laptops exhibit this same issue...


I called and talked to Sony support (2nd level) about this, and they seemed to think it was 'normal'. However, I made VERY sure that they opened a ticket on the issue in case I have battery problems in the future...

 

Seems normal to me that under power management options, if you were to look at the Power Meter that it would still say Charging even if it is at 100%. I don't think the problem is a BIOS issue, its just how these laptops seem to work.

This isn't to say that this trickle charge is or is not unhealthy for the laptop batteries but previous laptops I've had do the exact same thing. Not limited to, but including Dell Inspiron 4000, 8500, 8600, Sony S360, etc.

Given what I've seen of the SZ, the only time my battery seems to get really hot is when I use it on AC mode and play CPU/GPU intensive applications. If you take a look, the CPU is literally, pretty much right below the battery, just a little below it and the heat from the CPU can easily spread over to the battery.

Personally I think its a little bit of a hassle but I take out my battery when I plan to use it for extended periods of time when on AC mode. My outlet plug is a UPS unit anyway so I have battery backup even without the notebook battery plugged in.

 

My 4-month-old SZ is down to 1:15 of battery life with the screen all the way down.

Sony is sending a replacement battery.

 

I do notice that my battery gets significantly warmer when plugged into the AC as well. But what realy gets my goat is how the battery seems to discharge pretty rapidly all on it's own when turned off and left sitting for a number of days. I charged it up to 100 percent and then went off on a trip for a week. When I got home I picked it up and hit the power button, and nothing. It was dead as a door nail. I'm pretty sure this isn't typical as I've never noticed this kind of behavior on my other notebooks.

 

not to dwell on this, but its Sony laptops that does this. I have Dells before this and never had charging once it went to 100%. I think Sony does a cont charge because while the battery is plugged into the laptop it's ALWAYS being drained. Which is the reason why if I dont use my Sony notebook all weekend, when I turn it on, its almost in the the 89% drained. While my Dell still stays at 99%.

 

Some more random grumblings...

A Sony engineer told me that Sony laptops turn off their charging indicator (the double-flashing light under the screen) when the charge gets to about 85%. I've confirmed that at 90%, the light was NOT lit for double-flashing.

Later, a support hack told me that if the light isn't lit, it's not charging. (They didn't have a clue.) The hack transferred me to someone who supposedly had a clue, and this person said 'yeah, all sony notebooks are like that.' After explaining in detail (which seemed to be over his head) that perhaps all Sony notebooks are flawed, he became hostile. He said he'd push the ticket to an engineer and refused to give me a timeframe for anyone getting back to me.

Now I'm trying to remember why I paid a premium for a sony notebook.

There is certainly a flaw here. Either the battery IS still charging when it's at 100%, or it's NOT charging but reporting to ACPI that it is. The first could be dangerous with this battery technology (and at the very least, would result in a shorter battery life) and the second should be easy enough to fix.

I wonder who the class-action lawyer was that did the Apple iPod battery thing...

 

I think this flaw maybe attribute to the battery pack,because its interface protocol to the mainboard and the applied windows driver should be same across different notebooks.

 

The charging policy for Li-Ion batteries is "constant-current + constant voltage " if the bat pack is not depleted. Any extra charging after the pack reaches 100% its capacity might induce heat problem.

 

Check out this article and I think it may have the reason

http://tomshardware.co.uk/2006/01/28/toms_hardware_uncovers_power_drain_issue/

Paul

 

The Sony charging thing isn't limited to Duo processer machines, and the MS hotfix doesn't fix the problem either.

 

My SZ extended battery (the only one I own) is cool as a cucumber even when plugged in. Maybe it's a std battery thing?

I haven't noticed a big drop off in battery life and I keep mine plugged in most of the time.

 

My battery was down to 1:15 of runtime after 4 months.

Sony just sent me a new one and I am back to about 2:45.

 

I noticed the same problem staying on charging forever even after it hits 100%. I tried how fast it charges, 30% per hour for the first three hours, and then took another extra hour to charge the last 10%. Compared to Sony SZ, the Dell latitude D410, D620 completely charges in 2 hours. Okay, I can just live with it, but I'm really worried about the issue that have been posted here. Hope nothing is going wrong with my battery in my SZ240. I mean, what a premium notebook this is. I'm going to try leaving it unplugged for some time with power completely off, see what happens. Please update this thread if anyone finds anything.

 

Any updates on this? I just received my sz and noticed this "problem".

 

I was pleased to find this site as I have just bought an FE31H which has this 'feature' I called Sony and their answer (which came by email a couple of hours after the call) was to discharge the battery, recharge it and then disable everything and see how long the battery lasted, so they clearly hadn't understood the problem. As the operator said that she wold call me back in a couple of days we will be able to sort this out again (!)

What I did was to use the machione on battery only. It lasted 2hrs 50mins which is not bad for the first battery cycle compared to the quoted life of 'up to 3.5 hours'. I then put the machine on charge. The flashing light had gone out after 3 hours (when I went to bed) and when I came back this morning the machine was completely cool to the touch so I'm pretty happy that the charging is working OK but that the indication may be at fault.

 

I'm suppose to get a SZ for Christmas, after reading this post I will think twice. Is all Sony's models have the same problem?

 

For more information on Li-Ion batteries, please read through our battery guide.

Perhaps those with this problem could post whether or not they have regularly calibrated their batteries?

This is not normal behavior for a Li-Ion batteries. I have a couple of 7-year-old+ Li-Ion for an old notebook that were still holding charge after years of storage the last time I used them (about six months ago).

This particular behavior is normal. Some systems will quick-charge up until about 85% (or around there) and then slowly trickle-charge the rest.

 

Sorry to ask, but want to know more:

"Perhaps those with this problem could post whether or not they have regularly calibrated their batteries?"

How to do that?

 

Essentially it's fully discharging your battery every 30 charge cycles or so. Please read through the battery guide for more information where it's covered in more detail.

 

I use on a day to day basis laptops from different manufacturers.
So far, only sony laptop seems to do so.
Dell, Toshiba, Acer, Apple are the one I use every day, will all switched to "AC power" once the battery is full. Or at least will give me an indication that the battery is fully charged.
I'm writing this on a macbook pro laptop right now, and I read "Battery is charged"
AC Charger Information:

Connected: Yes
Charging: No

On the SZ, Charging will always show yes (when I run macos X on it).

 

I have just bought a SZ38GP (Australia) and I have no issues with charging. While charging the status is "charging" when complete it goes to "AC Power".