Microsoft W840DI manual Questions and Answers, Battery, Users Guide, Page

I did not use my spare battery for months. I have problem in recharging it.

My battery operation time is not as long as it should be. Why?

I can feel a mild heat next to the battery pack. Is it normal?

Battery User's Guide

2.3Questions and Answers:

Q:

A: The battery will generate heat during recharging and discharging. There is a protection circuit inside the notebook to prevent overheating. User needs not to worry.

Q:

A: The battery is heat sensitive and can only be charged to its maximum if the battery and its environmental temperature remain within 15-25°C (59-77°F). The more the temperature deviates from this range during recharging, the less chance there is for the battery to be fully charged. In order to recharge the pack to its full capacity, users are requested to cool down the unit by unplugging the AC Adapter. Wait until it is cooled down. Then plug in the AC Adapter to start recharging again.

Q: I did not use my spare battery for a few days. Even though it was fully recharged, there wasn't as much power left as a newly charged one. Why?

A: The batteries will self-discharge (1% per day for Li-Ion) when they are not being recharged. To make sure a battery pack is fully charged, recharge before use. Always keep the battery inside the notebook and have the AC adapter connected whenever possible.

Q:

A: If you happen to leave your battery pack to go through an extended period of self- discharge, say more than three months, the battery voltage level will become too low and needs to be Pre-Charged(to bring the battery voltage level high enough) before it automatically (for Li-Ion only) resumes its normal Fast Charge. Pre- Charge may take 30 minutes. Fast Charge usually takes 2~3 hours.

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