Battery Replacement: 2026 GMC Sierra 3500 HD SLE 6.6L V8

Where is the battery located in a GMC Sierra 3500 HD?

The video above shows you how to replace the battery in your 2026 GMC Sierra 3500 HD. We recommend changing the battery in GMCs every 4 years. Although some batteries last much longer, most batteries begin breaking down chemically after four years, so you could experience dimmer headlights and other negative effects before you have a dead battery in your Sierra 3500 HD that you need to replace.

The battery location in a GMC Sierra 3500 HD can typically be found in the engine bay, but may be in the trunk, fender or inside of the vehicle. You may need to remove the air filter housing, a plastic engine cover or parts of the cowl to find the battery in your Sierra 3500 HD. See exactly where the battery is located in your 2026 GMC Sierra 3500 HD.

Replacing the battery in your Sierra 3500 HD involves removing the terminals. When you reconnect the terminals, your radio presets are likely to be cleared out. In some Sierra 3500 HDs, you may need to re-enter a security code to get your radio to work again. Check for this code in your owners manual - it will usually be either a sticker or small card in the booklet. If you can't find it, call GMC and they will give you the code for free. In many GMCs, the transmission "learns" how you drive over time and makes adjustments, so you may experience altered driving dynamics as your car re-learns your driving style after changing the battery.