I plan on building a portable radio out of some spare car audio parts I have lying around, and would like to add the option to run off battery for portable uses or AC power (converted to 12V DC) when near a power source. I'll be running two speakers from a small amplifier, 2 x 15 watts from a 5 amp/hour sealed lead acid (SLA) battery (or possibly a NiMh). Here's where I'm stuck: I want the power source to automatically switch from battery to AC (converted to 12V DC) when plugged in, while simultaneously charging the battery, then back to the battery when it's unplugged. Basically, it would be similar to how a cell phone or laptop can run from a wall adapter while also charging the battery, and back to battery when you unplug the wall source, with a seamless transition.
All I could think to search for was some sort of mini-UPS system (uninterpretable power supply) and found a product by Mini-Box http://www.mini-box.com/picoUPS-120-12V-DC-micro-UPS-battery-backup?sc=8&category=1264
Does anyone have any experience with something like this, or could anyone point me in the right direction? I am open to recommendations for an "off the shelf" solution, or a somewhat simple DIY build that would accomplish my goals.
Thanks in advance!
All I could think to search for was some sort of mini-UPS system (uninterpretable power supply) and found a product by Mini-Box http://www.mini-box.com/picoUPS-120-12V-DC-micro-UPS-battery-backup?sc=8&category=1264
Does anyone have any experience with something like this, or could anyone point me in the right direction? I am open to recommendations for an "off the shelf" solution, or a somewhat simple DIY build that would accomplish my goals.
Thanks in advance!