Running Without a Battery

Not certain where to post this.

The bios battery in some notebooks is a rechargeable li-ion coin cell , and when you remove the main notebook battery and disconnect the mains, it will fully discharge itself in around 48 hours and the bios setting will be lost.

Now this could possibly cause the bios battery to fail to recharge, if you have a normal lithium coin bios battery you need not worry.

My Toshiba notebook came with the main battery already installed, as i assume to stop the bios battery going flat.

So i would try and find out what type of bios battery you have before removing the main battery for any length of time.

As i am not certain if these is any low voltage protection on the bios battery.

Just a word of warning.

 

John, the lithium BIOS batteries actually hold a charge for along time. I have one in my old Northgate, it sees AC power once every year or so, and it still powers up fine everytime. I also have a rechargeable battery in my Voodoo M360 based on the Compal CL-50, the system does not work, but it holds a charge for over a year without any problem.

K-TRON

 

Can I ask a question?

Since I have buy my leptop (Toshiba, x300). I have not used my battery becouse I don't need it... So my leptop runs without battery but AC is of course pluget in... Only when I'm not travling (This is not often, maybe 0-1 time in week, but when it is disconnected form AC it is for about 8 hours)...
Will this damage my battery ?, or anything ?

[Sorry My Bad English ]

 

K-TRON above does not think so, but why would Toshiba ship it`s notebooks with the main battery already install , I have had a 7-8 other notebook and they have not had the main battery installed.

If the bios battery is a li-ion rechargeable they do not like to be fully discharged and on some notebooks you have to totally strip them down to get to the bios battery.

The choice is yours, maybe we should give Toshiba a ring and ask them.

 

Just read my user manual and it says the bios battery will hold it`s charge for approx 1 month and then the setting will be lost.

 

Thats definitely different. I wonder why they choose lithium batteries than. Either the Bios sucks alot of power of they put a very small BIOS battery in.
A standard bubble cell can hold the 3v charge for many years, and I know my lithiums have lasted more than a month because I usually test them once a year to make sure they still run.

What is odd is that the RTC battery life is true. If you google RTC battery you will find a lot of websites addressing a error code on Toshiba's from low battery

If you wanted to, you could probably install multiple batteries in your system wired in parallel, so that the RTC battery lasts longer.

K-TRON

 

I think the most cmos battery is just a CR2016 3.0v lithium battery only..The same kind used for watches, calculators, etc..

Got 2 wires punched in on the battery(total 2 wires only) with a plug to connect to the mainboard.

If run out of juice, just buy another one to replace and solder back the same connection..

 

Maybe the battery is for emergency purposes in order to avoid data failure during start-up..

 

The bios or cmos battery is to keep the RTC(real time clock) running..

The OS when starting up at the welcome screen will check the system date. If too early, let's say the year is 1980(meaing the bttery has drained, can't keep the clock running), the OS won't start up..
Also, if even starts up, som program will check it too. Else will tell you that the program has expired..