Dr Jones was kind enough to clue me into the 7805 chip in my other thread 7135 drivers at higher voltages
It works from ~7V-30V and looks just like a 7135. For a 2s battery I’ll use a similar chip, the ld2981 which should work from 5.2V-16V. The dropout voltage is much lower (.2V@100mA-.007V@1mA) on the 2981 which allows it to work down to full discharge. The 7805 has a 2V overhead so it works with 3s or more. Both chips are available from Mouser but I bought the 7805’s off eBay. The 2981 also requires capacitors that the 7805 does not. They are available in different output voltages.