Uninterruptible Power Supply units have never been very sexy or popular unless you live in an area where power fluctuations or power cuts are common.
Yet, the idea of a portable UPS could be revived for laptops as they supersede desktops PCs and make working while commuting possible.¶ (opens in new tab)
Manufacturers often quote impossibly optimistic battery life for their products assuming that users don't want Wi-Fi or any form of connectivity or use their screens at their lowest brightness settings when in fact it is pretty much the opposite.
The main reason for such a product would be to offer a significantly higher battery life without adding any weight to the laptop itself.
Instead, the additional components would be combined with the existing power supply units and be a better option than buying higher capacity batteries.
These cannot be charged independently from the laptop and you still need to power off the computer to swap it.
To some extent, products like PowerTravellers' Power Gorilla (opens in new tab), New Trent's TY1800 (opens in new tab) or Energizer's Portable emergency battery (opens in new tab) are laptop chargers with built-in power pack (or vice versa), offering up to 70Whr in a 500g enclosure.
But they are expensive because they need to be compatible with a wide range of products (from cameras to smartphones) meaning that they require more electronics.
Ideally, laptop manufacturers should work with their ODMs to create such a product and offer it as an option. After all, who wouldn't be
Apple has been the most innovative company, having redesigned its MagSafe power adaptor for the MacBook range, with a magnetic connector and the electronics squeezed into the plug itself, and would be the ideal candidate to engineer something like that.