具有特定日期/时间的DateTime :: createFromFormat问题

I have been using the following code for a couple of months and it's been working fine, but now seems to have an issue with a certain time or time range. I have a GPS tracker that sends it's date/time like this: 150102235335

The format is ymdhis

$input_array[6] = 150102235335;
$datetime = DateTime::createFromFormat('ymdhis', $input_array[6]);
$datetime = $datetime->format('Y-m-d h:i:s');

Using that time, php crashes with the following error: PHP Fatal error: Call to a member function format() on a non-object

It seems that datetime ends up empty. However, using the time 150103004933 works just fine.

Can anyone see where I have gone wrong here, or is this a bug? Is there a better way to accomplish my date conversion? I am using PHP 5.4.35

h is 12-hour format; and therefore 23 hours is invalid. Only values in the range 00-11 would be valid.

H is 24-hour format