I had a diy effort that started with shurflo and avon analogue control all attached to a battery box. The control packed in after a year and I fitted a toggle switch for a simple on/off with no flow control. After another year and another toggle switch and a couple of fuses I now have a battery box, shurflo with just croc clips!
I do have a cheap diy pump box as backup but £160 for a pump and controller wired up on a board... Seems like a safer option.