That’s why
as highlighted in the video you need a B2B which controls the current draw whilst maximising charging from a smart alternator. This video from five years ago shows the old 30a
victron b2b which was far less efficient, larger and required a heat sinc. The new 50a B2B is a game changer not only producing more power but doing so so efficiently that no heat sinc is required due to 98% efficiency, far more efficient than the old 30a B2B which I think ran at around 70% efficiency.
As for drop in lithium that depends on the age of the vehicle and the charging equipment supplied with it. Any van produced in the past 4-5 years will most likely come with all of the ancillary equipment required, and drop in lithium is a realistic expectation. My van came with lithium compatible charging equipment, inc a Nordelectronica 40A B2B which as I said I recently replaced with a 50a
victron B2B. But older vans will require lithium charging equipment. But the benefits of lithium far outweigh any disadvantages for those who require more power, or who wish to go off grid in winter.
Lead batteries are relics from the past, heavy, low usable amperage, short life spans, varying voltage, greater internal resistance making them more difficult to charge, and in the medium term far more expensive. My old Varta lead batteries died after two years, lithium batteries can be charged thousands of times before reaching 80% capacity. Even then they are still better than lead batteries still in use today.