Back in the day when there were service stations, when you got gas the attendant would check your oil, coolant, and battery among other things. Ahhh the good old days. They would usually use a quart bottle designed to fill batteries. I walked into NAPA and asked for one and they had it for about $16. Works great and you don't need to see the level as it sets it automagically for you.
Bob Bartleson
'09 Knight, '16 Grand Cherokee