I have Dell Ispiron 15 3542 and I am surprised that my laptop has been switched off directly even though the battery is 100% charged and even the charging icon is displaying at task bar when the charger is switched on. But red light for low battery goes on blinking and when the power cord is removed it switches off and if switched on the power cord a message appears as "Your battery has met with parmanent failure and needs to be replaced and press F1 to continue and press F2 for setup utility"
Please help with the issues
I'd suggest you check Battery's status and health in the Battery Meter App. Please right click battery icon at taskbar, and then click on battery health. It should say Your Battery Is Performing Normally, if it say anything else then you most likely need a new one. Secondly, check battery status, if there's a checkmark in box by Enable Dell Extended Battery Life then uncheck it and restart computer.