I just tried one of the Deals Direct 2 channel multicolour net lights on DC. Running at 29V the net lights looks ok and results in a current draw of 400mA. Each series string is 9 LEDs, so there are 20 of those strings in parallel (10 per channel). This means each LED should be passing 20mA assuming all other things are equal. Maybe 28V would be a safer bet to make sure the LEDs stay within their ratings. It does look like you could split them into 4 channels with a bit of work. This would involve breaking into the LED connections at the "top side" (same long side as power input) and running new wires. Doable, but fiddly I'd say. The overall construction looks a bit light weight, so I'm not sure if these net lights would last more than a couple of seasons.