Need some advice!
I am designing a circuit for a small tin shed that requires backup power from a 12V SLA battery. It's an alarm with added features such as LED lighting and other additional features. All the circuitry will be in a "IP65 Sealed ABS Enclosure" (Size HB-6132) from Jaycar Electronics, which has pretty thick walls, and inside the box will be a small 12V SLA battery that will be kept on float charge (for backup) and the PCB's to make it all work, including the power supply/charging circuit.
My concern is the heat in the shed which may affect the SLA's performance. I read that the batteries should not be stored/charged in high temperatures. I'm sure that it won't reach the same temp inside the box if it's sealed and unvented, but I will probably need to vent the box because of the components that generate some heat - or is it not essential?. Inside the box will be some aluminium sheeting surrounding the walls as heatsinks. On a hot summers day, the temperature inside the shed can reach 45-50 degrees celcius quite easily, as there is a lack of ventilation.
- What do you reckon? Should I keep the box unvented to keep the battery cooler than the shed's ambient temp? Should I vent it and maybe use a fan (when it starts getting exceptionally warm)? Other suggestions?
Note that the float charger will have temperature compensation to keep the voltage correct.
Any help will be much appreciated.
Thanks, J