The Toshiba PA3729U-1BRS is a 6-cell rechargeable Lithium-Ion battery. It is held in place by a slider, making it easy to remove and replace very quickly and easily. In fact, using multiple batteries for extended battery life is very convenient, as users can swap in a fresh battery when the first is running low, and the affordable price of the PA3729U-1BRS makes buying an additional battery easy on the wallet.

The battery measures 0.9 by 3.8 by 8.2 inches, and weighs only 0.8 pounds. Its light weight makes it a great fit for the portable design of the Satellite and Qosmio series of laptops, keeping the weight down, which will appeal to travelers and other users who value mobility. Output voltage is 10.8V x 4000 mAh.

Total battery life is rated from 2 hours and 30 minutes to 3 hours and 20 minutes, depending on usage. Recharge time is around 4.5 hours, though this can also vary according to usage and also according to the model of laptop.

Overall, the Toshiba PA3729U-1BRS is a solid laptop battery that provides a lot of power in a compact and lightweight design. Its low price and easy installation makes it ideal for users who want to carry around an extra battery for extended life, and its fast recharge times ensure a quick turnaround before putting the battery back to work.

The Sony VGP-BPL21 is designed to have more capacity, and therefore longer battery life, than the original battery for your laptop. This does mean, however, that it is also larger and heavier than the original battery. In fact, its extra bulk will stick out from the bottom of the laptop or notebook, causing it to tilt slightly toward the user. This is by design, but may surprise buyers not expecting it.

The unit weighs 17.3 oz. and measures 1.5 inches by 8.1 inches by 2.3 inches. Its output voltage is 10.8V. The battery’s capacity is rated at 7500mAh, which is a significant improvement over the original battery, adding longer battery life.

The design of the Sony VGP-BPL21 is definitely geared toward battery life, but users will want to consider the balance between portability and extra power. Users who travel often or need hours and hours of battery life on the go will find it suits their needs, and may not mind the tradeoff of extra size and weight. Typical users who also value portability may consider using the original battery for most uses, and keeping the Sony VGP-BPL21 battery charged and available for the times when extra battery life is crucial. This allows for more portability the majority of the time, but extra power when necessary.

Overall, most buyers should find the extra battery life provided by the Sony VGP-BPL21 to be well-worth its price, as long as they don’t mind the extra size and weight.

This battery is guaranteed to either meet or exceed the specifications of the original battery that came with your Toshiba Portege, and will also interface with the Toshiba Power Saver Utility on your machine to help you monitor your available power with a charge indicator. This battery snaps in and out of the laptop’s battery slot in seconds, and is made from the same quality Toshiba parts as your laptop itself, guaranteeing compatibility and seamless function.

This battery has a 10.8 volt capacity, 6 lithium ion cells for extended power, weighs in at 0.68 pounds, and measures 8.13″ x 1.88″ x 0.78″. It is compatible with the Toshiba Portege A600, A605, R500, R505, and R600 series of portable computers from Toshiba, and comes with a one year limited warranty to ensure long lasting performance. In tests under grueling use, this battery lasted for approximately 5 hours, and most users can expect even longer life with their battery under typical use.

This battery is compact and powerful, a perfect match for your ultraportable Portege line. Offering long life and seamless integration to your system, this battery is a great option for a spare battery for longer trips, or as a direct replacement for your original battery. Additionally, it boasts 100% compatibility with Toshiba’s Power Saver Utility to make sure that you retain Toshiba’s superior power management utility, helping to ensure that you never find yourself suddenly out of power when you need your machine working the most.

According to Sony’s website, standard batteries for the VAIO TX series last between four and ten hours, whereas this battery has a life of between 6 and 15 hours, depending on usage. According to user reviews, after a year of continuous use, this battery still retains approximately 6 hours of life when used for text editing.

Being a lithium ion battery, this component is useable directly after charging to 100%, without the need for any additional charging or multiple charge and discharge cycles. If using this battery as a standby, it should be charge to 40% and stored in a cool, dry place to retain full function. Also, check the battery every few weeks if not in use, charging it up to 40% as necessary.

Lithium ion batteries also function best with only partial discharge cycles, meaning that whenever possible, you should recharge the battery before it completely runs out. A lithium ion battery will typically last for between three hundred and five hundred charge/discharge cycles, or two to three years. This can be extended by storing the battery at a diminished charge (again, 40% is the magic number for lithium ion batteries), and at cooler temperatures (15 degrees Celsius is ideal). If using this battery as your main power source, this does not mean the battery will die in two to three years, rather it means that after two to three years, the charge capacity of this component will begin to deteriorate.

Overall, this battery is a great replacement for the standard VAIO TX Series battery, offering greater battery life at a very competitive price. Taking proper care of this component will grant it a long and stable life as well, lasting as long as the laptop itself will.

Before purchasing a replacement Apple battery, it is important to be sure that a sufficient replacement  is being used. The necessary information is located in the user manual, as well as on the bottom of the battery unit. This ensures optimal performance of both, the battery and the notebook. Standard and replacement Apple laptop batteries utilize a Smart Battery System (SBS), that help manage battery energy, set the charger to the correct charge algorithm, predict running time, and provide a state-of-charge (SoC) indication. It also features an integrated microchip, that prevents overcharging, and lengthens battery life.

Replacement Apple laptop batteries come initially in a discharged condition, and require a sufficient amount of charging time before use. Each device has a recommended charging time, listed in the user manual, and may require 3-4 charge/discharge cycles before achieving its maximum capabilities. Users are also recommended to remove the power chord, when Apple laptop batteries are completely charged. This prevents any damage to the internal cells and allows the battery to perform at its best. When the device is powered-off, it is suggested to plug the power cord into the Apple laptop battery, maintaining constant movement of the energy cells.