No cause information is available.
When storing multiple laptop systems, it is a best practice not to stack them on top of each other. Other systems or heavy materials that are placed on top are likely to damage some of the systems at the bottom of the stack (Figure 1).
Figure 1 - How not to store your laptop systems.
It is best practice when storing laptop systems to put them in a rack. Systems are placed vertically next to each other and not on top of each other (Figure 2 and 3).
Figure 2 - Storing laptop systems in a rack.
Figure 3 - Storing laptop systems in a rack.
Another option is to use storage carts for the laptop systems (Figure 3 and 4).
Figure 4 - Storage of laptop systems in a Cart.
Figure 5 - Storage of laptop systems in a Cart.
Sometimes when space is at a premium, there is no alternative to stacking due to space limitations. If you must stack systems, it is suggested that you stack them in stacks of five (5) systems or less. Stacking systems any higher can damage the systems on the bottom of the stack, due to the combined weight of the systems on top (Figure 6 and 7).
Figure 6 - Limited stacking of systems for space conservation.
Figure 7 - Limited stacking of systems for space conservation.
There are some simple do it yourself (DYI) affordable concepts that may help you organize and store your laptop systems (Figure 8 - 10).
Figure 8 - Do it Yourself (DYI) Racking alternative options.
Figure 9 - Do it Yourself (DYI) Racking alternative options.
Figure 10 - Do it Yourself (DYI) Racking alternative options.
The following links give information about best practices for battery life when storing laptops: