4 hours of walking, found 1 battery nearly at the end, hidden in the gutter at an intersection between Carroll Island Road and the nearby shopping center.
Photo map (only the ones southwest of Eastern Ave). Drill down for more shots - I took nearly 150 and uploaded and geotagged over 50 of them today.
There's a path from Tidewood Rd. to Schmidt Rd, and I have a few photos I need to crop before putting them online.
The battery carcass:
p.s. The Baltimore Sun has a story that Miami Beach opened up on May 26th, after being closed for 7 years. Funny: I was there on the 24th.