Mike, did you need to adjust your generator control box for the AGM battery? When I had a sailboat 15 years ago, the high tech alternator regulators had a switch to select between Lead Acid, Gel and AGM batteries, and if I remember correctly the AGM batteries require a lower charging voltage.
I just got a new battery for my TR4 two weeks ago. The restoration is almost complete and it was time to start the engine for the first time.
I have never been to this store before, but I got a group 24 EXIDE battery from Batteries Plus Bulbs for $71 including 6% tax and after taking the core return off the cost.
I specifically wanted a battery with a totally flat top since I got one of those fake battery tar toppers from
https://www.tartopper.com and this battery was one of the ones that fit the bill. I believe the Topper cost $20. Another battery that would have fit the bill was a NAPA.
I used a wood plane to remove the modern style mounting tabs on the sides of the battery near the bottom, took the plastic lifting strap off and did the same with the strap mounting tabs. With the topper on it looks exactly like a period tar top battery and it beats the $300 cost of a reproduction tar top battery.
I was originally going to get a group 27 battery, but the tar toppers only come in group 24 size. The fake tar topper caps don't come in black like the original Lucas batteries supposedly had so I went with red to match the cars seat color.
Visit my new and improved personal website at:
www.jakegingervila.wix.com/bobs-vintage-cars-
Vila
1933 Chevrolet
1962 Triumph TR4
1984 BMW 633 CSi