It seems the lead acid batteries are being phased out. The lithium option can add $3500 to the cost. The lead batteries have worked fine for me. They have never ever ran down to affect performance and easily charge overnight. We had thought we might get a new one in the next few years but now I am wondering if we should do it before the battery change-over and the much higher new prices. This is just for use around the house which is never more than a couple of miles a day and usually under one mile. It is not used on any roads.
The advantages of Li ion are lighter weight and better energy density, and in my opinion they are easier to maintain. If lead acid batteries are left to sit in a partially discharged state they degrade in energy and power capacity, at least in my experience with car batteries.
But it sounds like you maintain them and they work for you, so there’s probably not any real advantage of Li ion for you.
Lead acid batteries must be kept fully charged all the time and held on a maintainer or they will lose capacity ~3% per day; if the battery is held in a less than full condition the cells will be irreparably sulfated which limits capacity and shortens lifetime. Lost electrolyte must be replaced with distilled water, so this is added maintenance not needed by Lithium. We had a big 400V bank in the lab that lasted over 30 years with proper care.
Lithium gives longer lifetimes by cycle life and age life if not kept fully charged all the time and operated between 80 to 20% State of Charge.
Phased out? Or just supply chain issues?
My friend, what you will find in virtually all areas is that manufacturers mysteriously reinvent the wheel ever 25 years or so. The goal is to sell something new to the public. Take electric cars for example. The technology absolutely sucks in every possible way. Does that stop them, no. They will try and coerce you into buying a big pile of crap.
To answer your question, there is nothing wrong with lead acid batteries. Don’t believe the hype.
The pro of lead acid battery packs are cheap.
Modern cell chemistries are almost better in every single way, including running costs because of lead acid’s large limitations.
A LifePO4 cell pack can be put right into place and easily give you 3x the capacity in the same size.
According to one Club Car dealer completely phased out. Other companies I don't know.
lead acid pro - cheaper*
li ion pro - everything else
*( and in this particular application, one of lead-acid’s cons, weight, does not really matter)