Bolding mine.
Originally Posted by
MSY-MSP
Returning back into the conversation for a bit. Was speaking with a friend over this weekend and he made a comment to me that at least shed light on the reason for the limitation of “only a cell phone”. The reasoning is that a cell phone only has a single battery. Whereas, laptops, iPads, and the like have multiple batteries. You only need one battery to power the device and have it run for a period of time. The extra batteries only give you longer device life away from charging. So what he was saying is that it is possible to create an explosive material that fits into the space that a battery would go, and that apparently the density can be made to appear on x-Ray similar to a real battery. Thus, you could get one of these through both the X-Ray and the power-on tests.
Most laptops I know of have two batteries -- a coin-cell CMOS battery (e.g., CR2032, lithium and not rechargable) just like what might be in a traditional digital watch -- and a big lithium ion battery. I have seen some in the distant past that have a third small-ish rechargable battery for memory retention; not sure if they do that any more. But the only battery capable of powering on the laptop is the main battery. The smaller battery couldn't source the amount of current required even if the right voltage were achieved through a dc-dc converter.
I've never heard of tablets like the ipad or e-readers having multiple batteries.
Now maybe your friend was speaking of multiple cells combined together into the main battery. I suspect, but am not sure, that most phone batteries contain only a single 3.7V cell.
The main battery in a laptop and maybe a tablet is going to contain multiple cells stringed in series (to get the required voltage which is higher than 3.7V) and possibly multiple of those strings in parallel (to increase runtime and maximum current). If there are parallel strings of cells, it would be completely plausible to replace all but one of the strings with some nefarious substance and still have the laptop boot and run for a significant time. But I have to imagine the density and thus x-ray appearance of the lithium ion cells and the nefarious substance would be quite different, and this difference would stick out badly because they would be next to each other. I suspect it would be very difficult (i.e., graduate level research) to tune the density of one to match the other without significantly reducing its effectiveness.
I would hope the software in modern carry-on x-ray machines could highlight large battery-sized structures that had the wrong characteristics. If not, increasing random ETD from ~1% to ~10% plus increased use of dogs would do much to mitigate any threat. The biggest problem would be how to sanely deal with the inevitable false positives (confiscating a false-positive laptop is not a solution). I don't really believe the bad guys could encase the material well enough to prevent ETD/dog detection.
I strongly believe that banning non-WEI objects is not an intermediate or long-term solution to any threat. Better detection is a solution. Jailing or killing terrorists is a solution. It should be criminal that the war-on-water has continued for nearly 11 years. We here and those in the press need to keep talking about the insanity of putting these fire hazards in the cargo hold which would very likely kill a planeload of people within the first year; maybe someday DHS will realize we have had enough. The best hope I have seen is that the press isn't just parroting "anything for security" this time; they are talking about the real risks such a policy would create.
Appreciate your posts on this -- seems like you have some insight and access to insight on whatever insanity is being proposed.