Re: [MacBook] Service Battery message
On Dec 13, 2011, at 12:08 PM, William wrote:
> Hello to the Group,
>
> I have an older MacBook. Once in a while I get a message in the Battery Icon saying Service Battery. The battery seems to be working normal. The charged usage time has gone down but I sort of expect that with age. It is around 2-3 hours. Looking at the System Profiler the battery has gone through 241 cycles.
>
> Am I near the end of the useful life of the battery?
Key battery information can be extracted using utilities such as Battery Health Monitor (free app) or by going to the Apple icon in the upper left corner of the screen and clicking on About This Mac>More Information>Power. Lithium ion batteries used in the MacBook's early models usually are good for at least 400 charge cycles, although I've got one with over 600 cycles that's still going strong. The other figures you should pay attention to are the fully charged voltage, which should be 12.6 volts or better, and the amount of original battery capacity remaining, which is expressed in mAh or milliamphours.
Lithium ion batteries like those in your MacBook slowly lose their capacity, even if they aren't being used and just sit on the shelf in their original packaging. Thus the reason I look at eBay sales of "new" batteries with a jaundiced -- and experienced -- eye. But you never know. I've got a $30 eBay third-party battery in my 2.16 GHz MacBook that shows a current capacity of 5004 mAh, which Battery Health Monitor says is 104 percent of the original capacity of 4800 mAh.
So your battery seems to be aging normally. The Service Battery icon may indicate a charging anomaly, such as loose connection, or perhaps an internal battery issue. If the battery gets hot to the touch when charging or discharging, I'd keep a close eye on it as that may be a precursor to a battery overheating or even catching on fire situation. Or it may be nothing more than the little "brain" inside the battery being confused. This can occur if you don't practice the Apple-recommended drill of unplugging your MacBook and letting the battery run down once a month or so. Besides being good for a good long battery life, it lets the battery's brain reset itself. I've often seen batteries regain substantial amounts of charge capacity after a monthly full-discharge cycle. YMMV.
HTH,
Jim Scott
