DC/DC Chargers, Aux Batteries, Hybrid Charging System

Installed a deep-cycle battery (Optima Blue Top) in a box on our bed cargo slide and am charging it with a Victron Orion DC/DC 50amp charger. The hybrid charging system on my '24 is causing an issue with Victron's engine-running detection algorithm. So, the options are either to find an engine running circuit to tap into on the truck or to use a CAN bus interface that detects engine running I think. Sometimes the charging system on the truck drops to 12.6 while driving, so I don't think it makes sense to drop the Victron's engine running sense that low.

Just talking through it and wanted to make a post in case people search online for the same issue.

Those of you with alternators on the newer hybrid trucks may not have the same issue? Not sure.

I'll be interested to see what suggestions emerge. This topic is certainly nothing new. Our 2008 Chevy Suburban used a similar system that cycled the alternator, causing occasional voltage drops.

About a year after we bought it new, we were on a family road trip and roughly 700 miles from home when I happened to notice the voltage had dropped. It looked exactly like what you'd expect if a belt had broken or the alternator had failed.

I called my shop mechanic in a bit of a panic, and he explained that it was an automatic fuel-economy feature. As it turned out, there was never any problem.

Still, being 700 miles from home, with a family of five, two dogs in the back, dusk approaching, and somewhere in the middle of Nebraska, it's not a great feeling when you think your alternator is failing.

My 3rd gens were tuned, so I could adjust the smart alt algo in the tune for my AGM dual batteries, not sure if that's an option on the 4g or not. Hesitant to tune this truck while it's under warranty, with all the issues that Toyota has been having with drivetrains.