Battery charge cycle count.

LostSoul 301281 wrote:
I've been reading a lot about battery life on Macbooks.
I read one person had problems after 150-something charge cycles.
I assume a "charge cycle" is how many times the battery has been charged?

In general when "100%" of the capacity of the battery has gone through one full discharge and recharge. Several partial cycles (not sure how that's determined) eventually add up to one full cycle.

Problems are from assorted reasons. Some could be from physical shocks while others can be random.

What is a decent cycle count? And at what point is it normally expected that a battery will need replacing?

It really depends on how long you've had it and what your typical use is. Right now I've had my MacBook for nearly 2 years and have accumulated 30 cycles. I started doing the calibration steps after several months and have calibrated nearly every month since I started doing that.

My current Health Information, in System Profiler is:
Health Information:
Cycle count: 195
Condition: Good
Battery Installed: Yes
Amperage (mA): -1104
Voltage (mV): 11879

That looks good. The negative amperage simply means that you must be on battery power. Mine is plugged in and reporting 0.

I've had my Macbook since august last year, and the battery seems to last about 3-5 hours.
I use AirPort all the time, as I have a TC that has taken over from my old router.
I also use my Macbook most days for at least an hour or two, longer at weekends if I'm home all day.

Will it be long before I need to look at buying a new battery?

If you're at home you probably should use it plugged in. The use of battery power is what leads to reduced capacity. That's simply the way rechargeable batteries work.

Hi LostSoul,

Leaving it plugged in all the time only creates a problem when it's plugged in "all" the time, as in for several months straight. So no, having it plugged in regularly will not create a problem. I keep my machine connected 85% of the time and it's not an issue.

Steps on battery calibration can be identified here:

http://support.apple.com/kb/HT1490

LostSoul 301281 wrote:
When I use it unplugged(running off the battery) I usually plug the power lead in when the power indicator reaches either 10% or when the warning comes up at about 5%.
But you're saying that I should keep it plugged into the power at home?
I thought using the power lead all the time might cause problems with the battery, because you're keeping the power lead/charger plugged in after the battery is fully charged.

The charging system doesn't "trickle charge" when you're near 100%. It simply allows self-discharge to bring the battery down to 94% capacity before it attempts to recharge. This prevents a lot of unnecessary "top off" cycles near maximum charge that could reduce battery life.

You can only charge to 100% if there is an uninterrupted plug-in from 94% to 100%. If you pull the plug while it's at maybe 97%, it won't charge again until there's a drop to 94%.

I've only had my MBP for three weeks, and I've completely depleted the battery just one time for calibration.

Most days I use the computer on battery power for a little while, say down to 90 percent or so, then plug it back in. I've been doing this maybe a couple of times a day.

I thought these small discharges would not significantly impact battery life.

Yet my system profiler says I have 11 cycles!

Does this cycle count seem normal for the type of usage?

Here's what it says in system profiler:

Charge Information:
Charge remaining (mAh): 6567
Fully charged: Yes
Charging: No
Full charge capacity (mAh): 6567
Health Information:
Cycle count: 11
Condition: Normal
Battery Installed: Yes
Amperage (mA): 281
Voltage (mV): 12543

I see I've posted this in the wrong forum. Will repost in MacBook Pro (late 2008/2009).

My Black Macbook is 2 1/2 years old - I use it almost entirely on battery power charging it when I think about it - recently my charger was turning from green to completely off (no lights at all) At first I thought the charger was going bad as I've had that happen right after I purchased the machine - Apple replace the charger - I ordered a new charger online, which arrived in days at a cost of 16 bucks US - a steal I thought - well same thing happened so I assume now my batter is going slowly toward death -

I downloaded Battery Heatlh Monitor and it conincides with system profiler in the details and condition of my battery. However, it also tells me I'm at 111% (442( of my battery cycles) and, that I only have a small amount of battery life remaining - look at the voltage and amps as compared to what some of you with newer batteries show - interesting right?

I am not unhappy with the battery performance - I have used the battery exclusively without AC power (I figure I have a laptop with battery why be plugged in? -

I assume it's time for a new battery right? Here is the data from system profiler - would appreciate any comments.

Steve


Charge Information:
Charge remaining (mAh): 3483
Fully charged: No
Charging: No
Full charge capacity (mAh): 4687
Health Information:
Cycle count: 442
Condition: Normal
Battery Installed: Yes
Amperage (mA): -1283
Voltage (mV): 1168