Requirements can change rapidly even within the same application (e.g. low-power vs. high-power military devices). From one commercial datasheet to another, the reported metrics vary, leading to trends rather than rules for what is included. Various groups have tackled this difficult subject by mentioning important criteria for batteries based on the application , focusing in-depth on a single application or a single criteria , comparing performance based on chemistry or internal components , or discussing criteria and considerations for multiple battery application . Some online sources also address the topic of battery criteria and applications .