You won't get spikes from a battery bank. From a wind turbine you get ups and downs depending how the wind blows. Closer to the ground you get also wind gusts, but the turbine output goes through the controller before it reaches the batteries. You should also have a resistive load, for the times when the batteries are full (overcharging might destroy them sooner than you expect).

You should have some voltage monitoring and current monitoring on the circuit you plan to feed the miner with .. and disconnect it if the batteries are depleted.


http://helium.powerprice.info/temps/ << see the last chart here on what I get in my backyard 10m above the ground.