Battery Heat Shield Sleeve

If you're running a lithium battery under the hood of your vehicle, heat is your biggest enemy, especially if the battery sits directly above the exhaust manifold. Under-hood temperatures can climb fast — especially on long highway drives. When a lithium battery gets too hot, it protects itself by turning off, which means your fridge, lights, or other accessories suddenly lose power at the worst possible time.

We tested this problem firsthand. With a Dakota Lithium 135Ah battery installed in our Omega dual battery system and a temperature probe tucked between the two batteries near the bottom of the tray, we recorded temperatures reaching 140°F during normal city driving and over 167°F after extended highway driving — the exact threshold where lithium batteries cut off discharge to protect themselves.

The solution? This heat shield sleeve, made by DEI (Design Engineering, Inc.) from their proven multi-layer elastomer laminate material. Simply drop your accessory battery into this sleeve before placing it in the tray. With the same temperature probe inside the sleeve in the same location, the results were dramatic:

• City driving: Temps barely climbed above 90°F
• A couple hours of highway driving: Maxed out around 119°F
• All-day highway driving: Peaked at just 129°F — well below the shutdown threshold

That's a drop of 38°F or more in real-world conditions. The difference between a fridge that keeps running on a long road trip and one that shuts off in the middle of the day.

The sleeve is flexible, easy to install, and is rated to withstand a 1,500°C flame for 30 minutes, so it's built for serious under-hood heat. It also provides electrical insulation with a dielectric strength of 6Kv DC, adding an extra layer of protection around your battery.

Currently fits Group 24 and Group 25 sized batteries. This pairs perfectly with the Genesis Offroad Omega Dual Battery System, which already includes an adhesive-backed heat shield applied to the bottom and sides of the battery tray for added protection.

If you live in a hot-weather region, this sleeve will dramatically extend the run-time of your lithium battery under the hood.