[Cycle]

The timer itself is tiny. I can hold it in one hand, and it weighs only a few ounces. I'm not sure how big the internal backup battery is, but it needn't be very large, it's essentially a digital watch with programmable timers that trip a small relay inside. The relay only clicks if you've got 120 volt power, so the battery's not powering the relay.

And there's no need to replace the battery if you leave it unplugged for a long time, just plug it in. It'll recharge the battery.

The block heater is maybe a few ounces... it's a flat thermal film that has adhesive on one side. You clean the underside of the block, heat up the engine until it's too hot to touch, plug in the heater until it's too hot to touch, then stick it to the block and squeegee out any air bubbles. Then you plug in the heater for 15 seconds and squeegee it again, then do that a second time. Then when it all cools back down, you seal it up with silicone sealant around the edge of the heater. I applied a second thick coat of silicone sealant after the first one got tacky, and completely covered the block heater, so it's sealed up entirely and small road debris hitting the heater bounce off the silicone instead of putting holes in the heater.

The heater gets the block up to about 150 degrees F, so the engine doesn't have far to go to be at operating temperature.

I used a block heater that is larger than recommended... this block heater is recommended for oil pans of from 3 to 6 quarts. Mine is only one quart. I wanted to be sure it gets the block up to temperature. Once the heater hits about 150 degrees, its internal resistance rises and the amount of heat it produces drops until it balances with the heat loss of the engine.