I am an electrical engineer therefore I know everything

Q. How do you know someone is an engineer?
A. They’ll tell you.

Electrical engineer.

Oh doG. I knew this one was going to be bad.

I will note, however, that he didn’t actually say he was an EE. He just said it and we were meant to infer.

I have worked with lithium batteries and done design for chargers, converters, and BMS’s.

I seriously doubt it. Or at least I hope not.

I would get a standalone BMS to charge and monitor a LiFePo.

BMS don’t charge batteries. “LiFePo” would be a Polonium battery.

Lithium is very sensitive to heat and charge levels.

Agreed.

A regular lead acid charger literally ‘dumps’ current into the battery.

What? First, that’s not what literally means. Second, the battery accepts charge – the charger can’t dump anything.

That risks a fire.

If our EE was working with lithium it was likely non-LFP chemistries. LFP is not prone to thermal runaway.

A LiFePo has to be charged a certain way and discharged a certain way.

It really doesn’t. Charge to a sane Vabs at a sane C rate and you’ll get excellent performance.

Regardless of what salesman say, a lithium is not directly swappable for a lead acid.

It can be. (overview)

The charge/discharge profiles are different and equipment designed for lead acid batteries may not work well with lithium.

That’s right, it may not. There’s a lot of daylight between may not and the will not that your comment implies.

Also once a lithium goes below 40% charge it is wrecked.

Demonstrably untrue. Cycle life estimates are typically predicated on discharge to 20% SoC with charge/discharge at ~0.2C.

It will never be the same and is effectively trash.

Your bullshittery is trash.

If you need a deep cycle battery for your RV I’d consider the Optimas or gel type batteries.

JFC.