Nicholas, I remembered to test my setup today: I disconnected the solar panel and load from the solar tender so it was only the battery connected to the solar charge controller/tender. I measured 0.1mA. That's the Battery Tender brand product I have previously linked to.
FWIW, thank God, I got the coop moved today. About 3/4 of a mile down a road and across the property. Tomorrow morning will be the first time the birds will have been outside...if my opener continues to work properly. 
--HC
