Yeah, without spending money on electricity, I will be making around $2 a day on the miner. I am ordering a big enough battery that should be able to handle it. If not, I'll do an automatic transfer switch in the future.
Yeah, most older cards aren't making much these days. I think both my 580 and 480 calculated to earn a combined .40 a day on Ravencoin... So these DOGE miners are really the way to go for a small setup these days.