Hi, I'm creating some monitoring and GPS system in my official bag, for that I'm using arduino, sim 900 seeduino board and Uln 2003 relay driver and 6 relays and 7805 regulator- 3nos and also 7812 - 1 no, While I finished with this components I closed everything inside a box and placed it in a bag its is closed circumstances, I'm just using 12 volt 4400 lead acid battery not lithium iron for voltage converters I m using heat sink also, in a wooden boox there is air ventilation holes also available even though in a bag monitoring system lots of heat available. so how to reduce it. my doubt is is it possible this kind of heat can affect a circuits and battery. If I use a DC to Dc converter is it possible to reduce a heat.