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How much does it cost to replace the BIOS battery?

B

Bubble99

macrumors 65816
Original poster
Mar 15, 2015
1,107
308
I'm looking for how much it costs to replace the BIOS battery on the MacBook Pro. Where it will no longer keep the date and time with out being plunged in. If it is unplugged it loses every thing.

Is it lot of work to replace it on your own?
 
That's a PC thing. Macs don't use BIOS, they use EFI. Date/Time is kept by main battery. If you're laptop is mid-2012 or later (post-retina), there are basically no user serviceable parts inside. You can't replace battery, SSD, or RAM. Might as well be welded shut from a user perspective.
 
So you saying my partition may be bad.

What about the battery on the main board it self?
 
If the Macbook is a 13" mid-2012 or older, the hard drive, dvd drive, battery, and memory can be upgraded/replaced.

Starting with retina MBPs, the only thing that may be upgradeable is the ssd.

The Macbook does not have a motherboard battery like a PC.
 
Audit13 said:
If the Macbook is a 13" mid-2012 or older, the hard drive, dvd drive, battery, and memory can be upgraded/replaced.

Starting with retina MBPs, the only thing that may be upgradeable is the ssd.

The Macbook does not have a motherboard battery like a PC.
Click to expand...

Than what hold the date and time when the laptop battery is dead and not plunged in?

Normally PC laptops run on battery when it is dead it runs on power from wall when both sorces have no power it than runs on battery on the board.
 
Not every macbook has a bios battery. There are still some that have a tiny button cell battery on the board, much smaller than the common watch battery but there is no way of knowing unless you remove the motherboard and have a look.

It is now customary for the macbook's main battery to provide the small battery supply that keeps the date and time, a job performed previously by a small watch size battery. On newer machines, the main battery supply goes through a voltage regulator circuit that drops the voltage to 3.3v which on circuit diagrams is usually labelled RTCV (Real Time Clock Voltage). This voltage then goes directly into the main 'All in one' BGA chip (CPU & Northbridge & GPU).

If you are persistently losing date and time, it could be any of the above that is causing the problem.
 
laptech said:
Not every macbook has a bios battery. There are still some that have a tiny button cell battery on the board, much smaller than the common watch battery but there is no way of knowing unless you remove the motherboard and have a look.

It is now customary for the macbook's main battery to provide the small battery supply that keeps the date and time, a job performed previously by a small watch size battery. On newer machines, the main battery supply goes through a voltage regulator circuit that drops the voltage to 3.3v which on circuit diagrams is usually labelled RTCV (Real Time Clock Voltage). This voltage then goes directly into the main 'All in one' BGA chip (CPU & Northbridge & GPU).

If you are persistently losing date and time, it could be any of the above that is causing the problem.
Click to expand...

So you saying the GPU and CPU is is dying?
 
Is this the same MBP that was 'acting strange after a power surge of lighting storm' ?
Did you reset PRAM & SMC as suggested ?.
 
Audit13 said:
If the battery is dead, the Macbook's date and time will return to the default settings.

When power is restored, you will need to update the date and time.
Click to expand...

What battery are you making reference to?

Main battery is close to 8 hours of use. I ran battery down to 0% in past where computer shuts off!!!!! Never lost date and time when I turn it back in.
 
Bubble99 said:
What battery are you making reference to?

Main battery is close to 8 hours of use. I ran battery down to 0% in past where computer shuts off!!!!! Never lost date and time when I turn it back in.
Click to expand...

When the computer indicates 0% on a working battery, the battery is not exactly at 0 voltage, there is still some trickle charge voltage left in the battery to keep the RTC signal going. This signal is what keeps the date and time active.
 
Sometimes the batteries are not calibrated that well and have less power in them than the computer thinks and completely gives out even if it's designed to give a trickle charge to motherboard. I remember one of my older macbook pro's would give out completely and I would have to boot from zero rather than from hibernate because the battery would give out during the hibernation process and then go completely dead.
 
syan48306 said:
Sometimes the batteries are not calibrated that well and have less power in them than the computer thinks and completely gives out even if it's designed to give a trickle charge to motherboard. I remember one of my older macbook pro's would give out completely and I would have to boot from zero rather than from hibernate because the battery would give out during the hibernation process and then go completely dead.
Click to expand...

So you saying it can show 4% but in reality it may be 8%

When it is at 0% and the computer shuts off because of no power how much battery power is left? Enough for week, a month or two months?
 
When the computer shuts itself off at 0% it actually goes into standby. If the standby power burns whats left of the battery you will see a white grayed out restore from hibernation upon startup. My computer was running out of power between the standby and the auto hibernate mode so it had to cold boot when you replug it in. The calibration for the battery was off.
 
syan48306 said:
When the computer shuts itself off at 0% it actually goes into standby. If the standby power burns whats left of the battery you will see a white grayed out restore from hibernation upon startup. My computer was running out of power between the standby and the auto hibernate mode so it had to cold boot when you replug it in. The calibration for the battery was off.
Click to expand...

How long does this last week, two weeks, month or two months. And than you have put in time and date again.
 
well usually the computer instantly pulls the date from the internet so it's no big deal :/
 
syan48306 said:
well usually the computer instantly pulls the date from the internet so it's no big deal :/
Click to expand...

Even with it plunged in and I do just a restart the screen goes white and grey and take long time to start and loses the date and time and wifi network.
 
New symptom that I have notice as of late.

When I turn the computer on some times it does not turn on and you have to press on button a number of times for it to turn on.

Does this sound like it may be more than than the battery that is gone and needs to be replace but also the main board may be on the way out or some thing else?
 
There’s another thread where this happened and their MBP died while at the Apple store. I’d get it checked out.
 
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