I've determined to power a mobile project (RFID reader with GPRS reporting system on a MEGA) with a 3.5Ah sealed gel battery. The unit will be powered with a solar panel, between 20 and 40W in size.
My question - is there a simple pcb unit available on the market that would charge the battery? I could use a conventional solar charge controller but these are relatively big and I'm tight on space on the project.
Tips would be much appreciated.