There is a lot of fear and misinformation circulated about LiFePO4 batteries in general and direct charging from the alternator in particular.

The discussions get a little weird.

Yeti aficionado: What you need is a $40 Yeti mug to put your coffee in.
Me: people have been drinking coffee way before Yeti was founded. A regular $5 mug is probably fine.

Yeti aficionado: But coffee is hot. You need a Yeti mug to protect yourself from burns.
Me: Yes, hot things can burn you. This is why we put coffee in mugs instead drinking straight from the carafe. Drinking coffee isn't rocket surgery.

Yeti aficionado: If you don't get a Yeti mug your coffee will get cold and you will have to throw that coffee away!
Me: We put coffee into insulated containers when we want to keep it hot (or cold, for that matter) Heat transfer and insulation are well-understood. It's not a big deal.

Yeti aficionado: But Yeti made a Youtube video showing that if you pour hot coffee on your head it could hurt!
Me: <sigh>