I did look at some Lithium that were "cheap" but discounted them because with tech moving so quickly, they are liable to be older generations of these batteries. I may be wrong though. We have Bluetooth on our
solar controller, so not worried about the
battery having it. One thing I did think of, these three weight a staggering 70kg! Three Lithium would be much lighter, although only 100AH. So if weight was an issue, I would have probably gone to look deeper into the cost of them and the necessary upgrade.