Well, I think I answered my question. In 1916, William Warner applied for a patent to allow Ford owners to use and recharge a 6volt battery for electric lights in Ford card. The device went on sale in 1917 and appeared in journals till about 1921 under his companies name. The device appeared to lose favour after 1919 when FMC opted to sell cars with a generator and electric starter. Attached is an illustration of his electrolytic rectifier, and a (fuzzy) picture of the assembly including a new dash to equip a Model T with electric lights and rechargeable battery.
I sold the dash for that system at Chickasha this year.