“Awesome and an Ebenezer is a “rock of remembrance”.”
Actually, it means Stone of Help.
Not, actually, but also. It was placed by Samuel as a memorial for God’s help in battle. That’s its meaning in the song - a rock of remembrance of all the Lord has done for you.
See here:
https://en.wikipedia.org/wiki/Eben-Ezer#Historical_mentions
Note the distinction in the two battles. The Israelites treat the Ark of the Covenant as a talisman or magic. In the second, victory comes only after sacrifice.
Read both events and understand the context. Take a look at Ichabod as well for even more insights.