Product Reviews

No, it's not a mouse mat. The N-Charge is for mobile workers who are away from the mains for extended periods. In this, the 10Ah version, the 12.8V voltage provides a total energy capacity of 128Wh. Considering that standard notebook battery capacities are around 10-15Wh, the N-Charge could theoretically increase between-charge times several fold. But all that energy comes at a cost: the VNC-130 tips the scales at 1.35kg, doubling the weight of your ultra portable.

To use the N-Charge, you need to specify your notebook's make and model at purchase time. The unit is then supplied with the appropriate voltage adaptor with the correct-size power plug. As well as the rear primary power connector, there's a low-power, low-voltage connector at the front for charging mobile phones and PDAs. Again, you need to specify which adaptor you

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want and Valence can provide the appropriate connector as an option. But this is where the system's generic nature can fail: the Nokia phone adaptor, for example, worked fine with some Nokia phones, but not with others.

What's more, a couple of pitfalls arise from the way the N-Charge connects to the notebook. It does this via the mains adaptor's power input, so the notebook has no way of distinguishing between mains and N-Charge power. If the notebook's battery isn't fully charged and the N-Charge is connected, it tries to charge from the N-Charge. This is inefficient, and Valence recommends the main battery is topped off before attaching the N-Charge.

Problem two is that when the N-Charge is connected, your notebook switches to its mains power-management settings. So you'll need to fish around in your power-management applet every time you switch from the N-Charge to mains.

But, these problems aside, the N-Charge simply works. Testing with an IBM ThinkPad T40p (see issue 106, p117), the battery life using both the N-Charge and an internal battery increased our intensive test result from a little over two hours to just over six. Under light use, the T40p's excellent seven hours became almost a week's worth at 18.5.

Lithium ion is an expensive technology, and this is reflected in the VNC-130's price. But if you do a lot of fieldwork away from the mains, it could be the answer to your prayers.