As you might have read, I have been very disappointed with the battery life figures on the Kohjinsha SC3. I was expecting a lot lot more from an Ultra Mobile PC built on Intel’s latest battery-optimised Menlow platform but it turns out that under normal use, this device is just as bad as many devices based on the previous platform. Over the last 24 hours I’ve spent a lot of time trying to analyse why and have finally come up with the reason. Invetec, the OED for this device, have cut corners. While the background drain (on the motherboard and power board) is better than on previous Kohjinsha’s, it’s no better than the HTC Shift, Q1 Ultra. All these devices can match the SC3 for background efficiency. About 4W minimum or 5-hours, is what you can expect with everything turned off but the processor.
OK, 4W is good but once the screen is on, boom! Up goes the battery drain by between 80 and 150%. This is exceptionally high drain for what appears to be a LED-backlit screen. Thank goodness that using the screen in a bright room requires only 3/8th brightness but it’s still about 3W of drain which is much higher than it should be.
The second shock comes when you turn the VIA, yes VIA!, USB Wifi module on. Connecting to a hotspot will push the drain up by over 3W. It will settle back to 2W after connection but this is, quite frankly, pathetic. A wifi module that takes more power than the processor is a joke. There are far more efficient Wifi modules out there. Did Inventec think they were designing a cheap netbook?
So from a background drain of 5W, if you want to surf the net in a bright room over Wifi, the battery life drops to a depressing 2hrs. This is an average drain of 10W which is no better than the devices mentioned above.
Breakdown, tips and summary follow…
