"Service Battery" warning - what can be done?

if it says service battery it means you will need a new battery soon. Use the current one until the charge it provides is no longer adequate for your needs.

You can try running the battery down to about 10% and then recharging but that is not likely to fix anything. That warning usually means there is an internal fault in the battery.

A cycle count is really not a measure of battery health. Although the predicted cycle life of a Lithium-Ion battery is 1,000 full charge cycles, that is a statistical prediction. There sill be some that fail sooner and some that last longer. The 1,000 prediction is merely the peak of a normal, bell-shaped curve of cycle life.

You need to take the MBP in to an Apple store genius bar or authorized service center for testing by the techs to see what is wrong with the battery.

not all batteries will last the same amount of time. Sorry.

Notice that I said the predicted charge cycle life is a statistical thing, and that some will fail sooner and some later. There are no guarantees that any particular item will meeet the predicted lifetime for the entire population of batteries produced. Same with an automobile, there are some that do not last long and have problems, some that never have a problem. It is all a matter of statistics.

I mainly use my Mid-2009 MBP powered from the mains and have now got the warning with the following system

information. In addition, it now seems to fade quickly if I do run it off the battery and when charging seem to get a hot

knee as well.

Is it likely that I will need to get the battery replaced?

Battery Information:

Model Information:

Serial Number: W0939AMAF77VA

Manufacturer: SMP

Device Name: bq20z451

Pack Lot Code: 0

PCB Lot Code: 0

Firmware Version: 3

Hardware Revision: 3

Cell Revision: 100

Charge Information:

Charge Remaining (mAh): 1141

Fully Charged: No

Charging: Yes

Full Charge Capacity (mAh): 2023

Health Information:

Cycle Count: 168

Condition: Service Battery

Battery Installed: Yes

Amperage (mA): 2041

Voltage (mV): 12522

GBorgs, greetings: You will need a new battery shortly. Note that the capacity is well down. It should be twice that or more depending upon the MBP. Not a good sign.

Ciao.

I mainly use my Mid-2009 MBP powered from the mains and have now got the warning...

You have encounterd what many people do: lack of use has shortened you battery life. A lithium polymer battery is like a human muscle--if not used it atrophies and dies. This Apple article:

http://www.apple.com/batteries/notebooks.html

has the following under the section "Standard Maintenance":

For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her notebook on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month.