Couple of comments ....
Many (far too many) Lithium batteries go into a sleep mode when they detect the load on them is at a 'noise' level. This is a situation that is totally unsuitable for a Motorhome/Campervan environment where many vans will have just a small load a lot of the time and owners tend to try to save power rather than having to use power for no reason just to keep the
battery alive, like Steve has had to. A daft situation, I know.
This is not limited to KS Energy batteries by any means. Other brands of batteries have the same issue (and spoken to customers of those other brands who have sleepy batteries).
The only supplier I am sure of who is aware of this situation and has taken steps to address this problem is Alpha Batteries, who specifically tell the factories who make their batteries to disable any sleep modes as they know it is not something their customers want - and I can confirm this is the case as the first thing I did when I got a couple of brand new batteries to test from Alpha was to check for the presense of this feature. Right now the Lithiums in my Motorhome have been disconnected from the Habitation system (part of how the Hybrid system works) for over 7 days, with the only load being a
BMV-700 (~4mA draw, so noise level) and they are still awake
Ref the alternator thing and the wider charging question, there are different points of view on this. My own take on this is that as the charging characteristics of Lithiums Batteries mean they will take a much greater current than a Lead
Battery and often for a much longer time (most people swapping from Lead to Lithium tend to also fit a bigger bank and use more power) the charging routes are under a lot more strain.
A charger that the designers built to charge a Lead
Battery whose charging pattern means the charger will be running at maybe 25% of its output for a lot of the time will suddenly be running at 100% for hours. Personally I question that is a good idea. If you have a charger failure on the frankly quite poor and limited Sargent Charger, this could result in a replacement cost of maybe 3 times the cost of just buying a better charger to start with, even ignoring the inconvenience of sorting out a replacement Sargent and its fitting.
An alternator on an older van may not have the same thermal protection as a newer one. It may do but it might be worn and if a high-power relay connection (such as a standard D+ controlled relay or a VSR) is used for Split-charging, the much higher charge currents a Lithium
Battery can take compared to a Lead
Battery can either expose a fault or bring a failure sooner. The use of a B2B, as well as setting up a profile that ensures the correct charging voltages, acts as a current limiter and a bit of a brake on potential alternator overload.
Same consequences as the Mains charger.
Maybe being overcautious, but better safe than sorry.
