Vehicle runs on the battery alone. Been to 2 dealerships. How can it be fixed?

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. Your explained concern and the lack of any success apparently in diagnosing what is wrong is a little bit shocking to me. The single most common problem in getting a diagnostic test completed with a result is when the problem simply is not occurring. "Burned out 3 batteries in a year" - this quote indicates that the batteries have somehow failed - maybe after being fully discharged and recharged too many times due to something draining? What do the diagnostic results that you are paying for reveal? If you are having stalling on the freeway, and your battery ends up fully discharged, it would appear that the charging system is not working as it should, as the alternator should be constantly recharging the battery -- and the battery provides consistent reference voltage and needed amperage power to run all the vehicle components while the engine is running. Something is not adding up here, and since you've had dealership service departments attempt to evaluate and diagnose your concern with no luck, I'm going to suggest another opinion -- from a third party repair shop near you. Check the link below to find a shop who can take the time to really dig into what is wrong. https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.