Eee Pad Transformer TF101 Honeycomb 3.2.1 Battery Drain Solution

Asus Android Tablet - Eee Pad Transformer TF101 is one of the best tablets available in market as of Oct 2011. Not only because of its reasonable price, but also because of its IPS LCD panel, and its smart keyboard/dock design. However, one of its drawbacks is the relatively short battery life without the extra battery inside the dock.

What makes the situation worse is after the recent upgrade to Honeycomb 3.2.1, the tablet started to drain much more power than it used to do, and that is regardless the dock being connected or not. I tried suggestions found online using Automateit or Auto airplane mode, but the system was still using a lot of power. It seemed that the system never went to sleep.

While I was suffering with this bug, I came across a "solution" accidentally and would like to share it with all affected users. By inserting a microSD card into the slot on the tablet itself, this problem went away! This can be easily verified when a dock is connected - the light next to charging connector blinks even when the tablet is supposed to be in sleep. After the insertion, the light stops blinking.

I hope Asus can solve this problem in their firmware soon so users who do not know this trick will be saved. However, till Asus fix the problem, this trick can help us use the tablet as it is intended to be.

P.S. My tablet and dock are B60 version, so I cannot say whether it will work on your hardware if it is a different version.

Update Nov 9, 2011
With the latest firmware update (Android is still 3.2.1), this battery drain issue has been fixed. No need to try the trick here anymore.

If you would like to improve the battery life further when the tablet is in sleep, use Auto Airplane mode app to set the tablet into airplane mode when the screen is off. The reason this extends battery life is that the system fetches information over the internet from time to time while it is in sleep mode, which consumes extra power. However, if you are using VoIP software and would like to receive incoming calls, you cannot and should not use this app.

When the tablet is docked, it seems that disabling the touch pad improves battery life further in sleep mode.