A basic travel mug is a blessing. You can leave home with a hot cup of joe, and it won’t splash out of the mug and all over your truck’s interior. But a travel mug that actually keeps hot coffee hot, hour after hour, is a near miracle. Heated travel mugs use a variety of technologies to keep the java fires burning, from rechargeable batteries to plug-ins that will fit most vehicles. And once you’ve juiced the mug itself, you can tote your heated travel mug wherever you go. They’re just as useful around camp or at the beach or mountain cottage as they are on the highway.