Car Battery Side Terminal Bolt Size

Occasionally we receive questions from customers about specifications of our batteries that may not be obvious or apparent. That would include bolt sizes. We've previously mentioned the threaded terminal bolt size on our BLUETOP batteries is 5/16 coarse. We've also received questions about what size bolt fits in our side terminals. That answer is a 3/8 bolt. However, the length of the bolt may vary. Autoparts stores will typically stock the right length for your vehicle, but it can vary. For instance, many GM vehicles use a bolt that is 1.1 inches long, while some use a bolt that is 1.6 inches. We know many people using OPTIMA batteries may have custom battery connections that may change the bolt size they use, but if you're looking for a bolt for a stock application, your local quality auto parts retailer can probably assist you.