AutoStoned replacement battery died in the challenge car and won’t take a charge nor start the daggum thing. Since I’m not the original purchaser nor the previous owner has it under their name and number, AutoStoned wants $150 to replace it!!! I picked up the old one and walked out.
What are my options for a stockish size battery?
There are non-AGM lawn tractor/utility batteries that fit well and have vents. I paid about $30 for one. It started the car like any other Mists battery this summer/fall. The car is stored in the winter. I don't know if it will last as long as an automotive battery. The warranty was shorter.
I've had good luck with the Marathon battery. I've bought them for at least three Miatas.
http://www.batterymart.com/p-12v-mazda-miata-battery.html
I used the same exact battery for my street Miata and Spec Miata as I did for my riding mower., just with reversed posts. Worked fine, and got nearly three years out of the one in the street car in the Florida heat. Best part is the $40 price.