Odd behavior when plugging in laptop.

[Born2bwire]

I can't figure this one out. I don't keep a battery in my laptop since the battery time is so low and I carry my laptop to and from work everyday. But lately, whenever I plug in my laptop it automatically turns on and some of my BIOS settings are reset. In addition, the system clock keeps resetting to the same time on January 27, 2012. Rather annoying but I haven't noticed any loss of data or OS restores going on. The only thing I can think of is perhaps the CMOS is getting reset everytime I plugin. I really hope it's not the battery because that would mean a full strip down of the laptop and it's not designed to be user accessible.

 

[corkyg]

Unfortunately, that behavior does point to the CMOS battery. I run my Thinkpad the same way, but that never happens. Could it be that the CMOS battery in yours gets charge from the battery?

You might try putting the battery in for a day or so and see if that behavior changes.

 

[Born2bwire]

Well that really stinks. I'll give it a try with the battery in place and see what happens. Man, I don't think I've had to replace a CMOS battery in at least 15 years.

 

[mrblotto]

Yikes....yeah, kinda does sound like a CMOS battery.

Well, look on the bright side - I'd rather have to just replace a $2.00 battery than a much more expensive laptop!

 

[Born2bwire]

Yikes....yeah, kinda does sound like a CMOS battery.

Well, look on the bright side - I'd rather have to just replace a $2.00 battery than a much more expensive laptop!

The problem is that the dismantling of the laptop is rather complex and people have broken their keyboards doing it. I have an Asus G73JW. Basically, I have to remove a back panel, the optical drive, then turn it over to remove the keyboard, disconnect the keyboard, dismantle the case, remove the monitor, extract various parts like the fans so that I can pull out the motherboard and turn it upside down to access the CMOS battery.

The process is detailed here: http://www.youtube.com/watch?v=Tp90M_N6dzs

The alternative would be to have the laptop RMA'ed, which thankfully is a year and a half into the two year warranty. The only problem is that I rely on the laptop for all my work and such. I can't really afford to send it off at the moment.

 

[pcgeek11]

The problem is that the dismantling of the laptop is rather complex and people have broken their keyboards doing it. I have an Asus G73JW. Basically, I have to remove a back panel, the optical drive, then turn it over to remove the keyboard, disconnect the keyboard, dismantle the case, remove the monitor, extract various parts like the fans so that I can pull out the motherboard and turn it upside down to access the CMOS battery.

The process is detailed here: http://www.youtube.com/watch?v=Tp90M_N6dzs

The alternative would be to have the laptop RMA'ed, which thankfully is a year and a half into the two year warranty. The only problem is that I rely on the laptop for all my work and such. I can't really afford to send it off at the moment.

OMG. What a piece of crap design.

I love my Thinkpads. Open bottom cover, remove CMOS Battery, Plug in new CMOS battery, reinstall cover, Done.

 

[Born2bwire]

OMG. What a piece of crap design.

I love my Thinkpads. Open bottom cover, remove CMOS Battery, Plug in new CMOS battery, reinstall cover, Done.

Yeah, the design is terrible but the laptop is fantastic. Great performance but with a very cool and quiet system. My favorite "design choice" is that there are four RAM slots and the manual says that you have to fill them up in order, 1-2-3-4, if you want to use 1, 2, 3, or 4 DIMMs. But only slots 1, 2 and 4 are directly accessible. To get to the third one you have to open up the computer as above. So if you got the laptop with two DIMMS and wanted to add a third, you had to take it apart (though to be fair, it came with three or four DIMMS installed).

 

[pcgeek11]

How old is the system? In my experience the CMOS battery should last in excess of 5 - 6 years.

I have a Dell that is 10 years old with the original CMOS battery.

 

[mfenn]

How old is the system? In my experience the CMOS battery should last in excess of 5 - 6 years.

I have a Dell that is 10 years old with the original CMOS battery.

Statistical variance in the coin cells. Somebody is bound to get unlucky.

 

[Born2bwire]

How old is the system? In my experience the CMOS battery should last in excess of 5 - 6 years.

I have a Dell that is 10 years old with the original CMOS battery.

It's only a year and half old. I'd be surprised as you are if it really is the CMOS battery.

Unfortunately, that behavior does point to the CMOS battery. I run my Thinkpad the same way, but that never happens. Could it be that the CMOS battery in yours gets charge from the battery?

You might try putting the battery in for a day or so and see if that behavior changes.

Well, what do you know. This morning I put in the battery and booted up and had no problems. BIOS settings are the same as when I shutdown, the clock is still correct. And it did not automatically start up when I plugged it in. Funny thing is though, I did not put the battery in until before I started the computer. The laptop sat unplugged sans battery all night and I highly doubt the battery has any charge on it either since I haven't used it in many months.

 

[corkyg]

Possibly the CMOS circuitry can draw from the main battery when necessary. Let it be for a day or two, then remove the battery and try booting on A/C adapter only.

 

[Born2bwire]

Possibly the CMOS circuitry can draw from the main battery when necessary. Let it be for a day or two, then remove the battery and try booting on A/C adapter only.

Tried it this morning without the battery but no dice. Well, it works when I start up with the battery in the computer (regardless of whether or not the computer had the battery in between startups) so I guess I'll just keep the battery installed. I'm not walking up a mountainside to get to the office anymore these days so the added weight isn't too much of a problem. Eventually I'll probably have to get it RMA'd.

Thanks for the help.

 

[paul878]

You have one of those laptop that the cmos battery is charged by the main battery, just leave the main battery in.

 

[Topweasel]

The reason CMOS batteries last so long isn't because they get charged from wall/system battery. It's because they rarely get used. On desktops even when powered off, you are still plugged into the wall and that is used to keep the CMOS powered up. In a laptop generally even if you have the device unplugged you would get weeks out of the battery before the CMOS used up that charge. But if every day you run without a battery in, with the unit unplugged, you are going to be using that CMOS battery power.

Perfect example is my main desktop. I recently moved temporarily into a room that is a bit small for a full desk and full tower computer. So I set my laptop up instead. Its been three months. I am pretty sure in May when I move, if I set my desktop back up, that battery will be dead.

Edit, not to say their aren't rechargeable cmos batteries. Just that a 2032 isn't a rechargeable battery.