I just replaced my Energizer GP 49 in my 86 SDL after 8 years. It seemed fine, but I didn't want to trust it going into winter. The battery was made by Johnson Controls and is the third J.C. battery that I've owned , the other two died around 8 years. I replaced it with a J.C. from Auto Zone. Johnson Controls makes batteries for the following brands: Die Hard, Interstate, Auto Zone, Energizer, and a few Everstart (Wal Mart). I'm not saying that they make all the batteries for these brands. You have to check the fine print. For example, the group 49 at Wal Mart is an Exide.

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback