MacBook Battery
- Thread starter tjguitarz
- Start date
cgdoc519
Christian Gamers Alliance Staff Manager
I have had a mac book for a year and have mostly left it charging all the time. Newer macbooks have a built-in lithium-polymer battery. Here is the wiki insert on the battery.
"LiPoly batteries must be charged carefully. The basic process is to charge at constant current until each cell reaches 4.2 V, the charger must then gradually reduce the charge current while holding the cell voltage at 4.2 volts until the charge current has dropped to 10% of the initial charge rate, at which point the battery is considered 100% charged.
Balance charging simply means that the charger monitors the voltage of each cell in a pack and varies the charge on a per-cell basis so that all cells are brought to the same voltage.
The charge should not be terminated on reaching a cell voltage of 4.2 V because the capacity reached at that point is only 70% of full capacity; charging at the reducing current necessary to hold the cell voltage at or very near 4.2 V must be continued until the charge current drops to 10% of the initial charge rate.
It is important to note that trickle charging is not acceptable for lithium batteries; Li-ion chemistry cannot accept an overcharge without causing damage to the cell, possibly plating out lithium metal and becoming hazardous. Most manufacturers claim a maximum and minimum voltage of 4.23 and 3.0 volts per cell. Taking any cell outside these limits can reduce the cell's capacity and ability to deliver full rated current.
Most dedicated lithium polymer chargers use a charge timer for safety; this cuts the charge after a predefined time (typically 90 minutes)."
With all that said, apple has a system to stop the charge once you battery charge cycle is complete. So you should be fine leaving it on the charger. Mine will still last as long as it did when it was new, minus normal battery degradation.
"LiPoly batteries must be charged carefully. The basic process is to charge at constant current until each cell reaches 4.2 V, the charger must then gradually reduce the charge current while holding the cell voltage at 4.2 volts until the charge current has dropped to 10% of the initial charge rate, at which point the battery is considered 100% charged.
Balance charging simply means that the charger monitors the voltage of each cell in a pack and varies the charge on a per-cell basis so that all cells are brought to the same voltage.
The charge should not be terminated on reaching a cell voltage of 4.2 V because the capacity reached at that point is only 70% of full capacity; charging at the reducing current necessary to hold the cell voltage at or very near 4.2 V must be continued until the charge current drops to 10% of the initial charge rate.
It is important to note that trickle charging is not acceptable for lithium batteries; Li-ion chemistry cannot accept an overcharge without causing damage to the cell, possibly plating out lithium metal and becoming hazardous. Most manufacturers claim a maximum and minimum voltage of 4.23 and 3.0 volts per cell. Taking any cell outside these limits can reduce the cell's capacity and ability to deliver full rated current.
Most dedicated lithium polymer chargers use a charge timer for safety; this cuts the charge after a predefined time (typically 90 minutes)."
With all that said, apple has a system to stop the charge once you battery charge cycle is complete. So you should be fine leaving it on the charger. Mine will still last as long as it did when it was new, minus normal battery degradation.
vibrokatana
New Member
I'm still on my original battery on my 4 year old macbook and get 3.5-4.5 hours (which is virtually identical to when I first got it). I leave it plugged in most of the time and rarely deplete the battery all the way.
Joshinator
Christian Gamers Alliance TeamSpeak 3 Server Opera
im on a macbook from 2006, and my battery doesn't last even an hour 
im on a macbook from 2006, and my battery doesn't last even an hour
My old MacBook Pro had the same issue. I started with 3.5 hours and dropped to just over an hour. I took it to the Mac store and they took a looksie. Turns out I had over 700 charges in just a little over 2 years...