Replacement for UNISYS 11J8639 Laptop Battery

• 10.8V 4000mAh Ni-MH Laptop Battery (black)
• Product Type: Replacement Battery (Brand New)
• Highest quality Japanese battery cells
• 100% original manufacturer compatible
• Brand New, three years warranty
• Guaranteed to meet or exceed original specifications

How to maximize and battery performance?

It is recommended to condition (fully charge and discharge) tde new battery few times to allow it to reach its maximum rated capacity.
Condition tde Ni-MH and Nicd battery at least once a montd. It will reduce tde memory effect.
Use tde battery at least once a montd even it was kept in a dry and cool storage.
Clean tde metal connector (tde contact to tde notebook, usually in color of gold or silver) by alcohol or Electronics Cleaner Degreaser. It will maintain tde good conductivity,which improves tde power conduction from battery to Notebook.
Fully optimize tde Power Management features provided in system BIOS, and Operating System will also impove tde battery performance.Consult tde user's manual to fully understand tde usage of tdese features.

Is there any danger in leaving a laptop on 24 hours a day?

As long as it's in a well ventilated area, there's no danger. At least, no more danger than there would be if you left your desktop computer on all day. The danger to laptops is overheating. Because all the hardware is in such cramped quarters, it tends to get very hot. The bottom gets hot, so be careful where you put it. You may even want to put it on something raised so the air can get to the bottom. If you leave a laptop on blankets or a bed, it will often overheat because the insulation of the material is keeping the heat in. A tip that may help you when you're transporting your laptop is to take out the battery to ensure that you don't accidentally leave the laptop on.

Important note : Beware of refurbished Li-ion laptop batteries for bargain prices, due to the volatile nature of the Lithium Ion compounds, batteries must have matching cells and correctly calibrated control & safety electronics. All our new laptop batteries are made to the highest standards by quality manufacturers that also make original laptop batteries for many of the big brand names. Refurbished Li-ion laptop batteries are usually sold at highly discounted prices and thus are normally produced for the lowest possible price, often with little regard for thier long term stability, this can lead to them overheating or in extreme cases catching fire or exploding, this one area where quality should not be sacrificed for cheapness