Battery won't fully charge

[Saint in Paradise]

My wife has an Acer laptop that for the last 2 weeks or so will not charge up to more than 87% instead of 100%. It doesn't matter how long the charger is plugged in. Any tips on how to get it charged to 100% again please ??

[alpine_saint]

My wife has an Acer laptop that for the last 2 weeks or so will not charge up to more than 87% instead of 100%. It doesn't matter how long the charger is plugged in. Any tips on how to get it charged to 100% again please ??

 

I recommend you be careful. Lithium ion batteries are a dangerous pain-in-the-arse. You have no idea how much intelligent protection has to be built in to prevent overcharging and discharging to far Lithium ion batteries can EXPLODE without the management system. I suspect one of two things :

 

1. The battery is damaged/degraded. Get a new one

2. Check no-one has played with the PC power / shut-down settings

 

I wouldnt recommend you just carry on regardless.

[saint_stevo]

let it drain down to nothing and then charge it again

[Pugwash]

Worth reading:

 

http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

[alpine_saint]

let it drain down to nothing and then charge it again

 

Not a bright idea if there is already evidence the battery management aint working properly :

 

Over-discharging Lithium-ion

 

Li-ion should never be discharged too low, and there are several safeguards to prevent this from happening. The equipment cuts off when the battery discharges to about 3.0V/cell, stopping the current flow. If the discharge continues to about 2.70V/cell or lower, the battery’s protection circuit puts the battery into a sleep mode. This renders the pack unserviceable and a recharge with most chargers is not possible. To prevent a battery from falling asleep, apply a partial charge before a long storage period.

 

Battery manufacturers ship batteries with a 40 percent charge. The low charge state reduces aging-related stress while allowing some self-discharge during storage. To minimize the current flow for the protection circuit before the battery is sold, advanced Li-ion packs feature a sleep mode that disables the protection circuit until activated by a brief charge or discharge. Once engaged, the battery remains operational and the on state can no longer be switched back to the standby mode.

 

Do not recharge lithium-ion if a cell has stayed at or below 1.5V for more than a week. Copper shunts may have formed inside the cells that can lead to a partial or total electrical short. If recharged, the cells might become unstable, causing excessive heat or showing other anomalies. Li-ion packs that have been under stress are more sensitive to mechanical abuse, such as vibration, dropping and exposure to heat.