Earlier we posted step by step instructions to unlock iphone 3G/3Gs on iOS 4.2.1 using ultrasnow 1.2 which requires user to update the baseband to 06.15.00. Now it seems that some of the users are having poor batter issues with their phones. In some cases the phones even gets very hot. Cydia has already started working for an official solution for this problem, and surely it will take some time to come up with it but for those of you who don’t want to wait you can follow the following steps to fix this drain issue.
Here is the statement from Sherif Hashim:
On a very important side note, before anyone starts to complain about battery drainage issues after installing the new ultrasn0w on the 6.15.00 updated BB, the culprit here is not ultrasn0w, it’s the hacktivation process (activating the phone by pwnage tool or redsn0w rather than using an official carrier sim to do so) that u mostly did while jailbreaking.
The 4.1 and 4.2.1 ipsws unlike their old ancestors, seem to keep looking for valid push certificates all the time, either thru your wifi, or thru y
our cellular data network (which u only have after installing ultrasn0w and hence u accuse it) , this can be seen clearly if u have a cellular working data plan for 3g or edge and u watched the settings > general > usage > cellular network data (sent & received are continuously increasing even without using any internet traffics on the phone) , this will also render the phone going hot even in stand by mode and also very rapid battery drainage occurs plus consuming ur data if you were not on an unlimited plan.
Method 1: In this method you will need to have a official iPhone SIM card. You have to put your SIM in the iPhone and then you have to activate it officially. After you have activated your phone with this SIM card then you can take it out and switch back to any SIM card you like.
Method 2: In this method you can install SBSettings and turn your 3G off after every time you use it which will prevent the battery drain issue. But this method is slightly annoying and tedious.
Method 3: Currently this method is not available. But according to a member of Dev Team, an official fix is being worked on which will be released on Cydia very soon. When this official fix will release in Cydia you will have to install it on your iPhone.
You can try one of the above method to fix battery drain issue after unlocking iPhone 3G, iPhone 3GS on Baseband 6.15.00 with Ultrasn0w 1.2