by nerman8r
Thanks Grrrarg! You said mostly everything I wanted to say!To make any energy off of Monster Batteries, you need to spend five energy total: 2 to buy it and 3 to put on it, so that after three turns you've received six from it and made one measly energy. It just gets worse from there. (If you put six on it, you won't get extra energy until four turns later.) Look at other cards that cost that much and you'll see they are much stronger because they help you pretty much right away. Add to that the common problem where you finally get enough energy to buy a six-energy-costing card and then are killed before it even becomes relevant.
If someone gets a *big payoff* from Monster Batteries, it indicates to me that their opponents didn't know how to play well. Hint: focus on winning instead of building energy to buy a card that much later will let you buy a different card which will then help you win.