thats an RBC7, aka two of the bigger batteries with bolt holes.
it’s went fine twice now, soon to be three times but, two of those three times, i’m using fullsized RV/Boat batteries for maximum run time.
HOWEVER two of the thee 12v 10ah batteries tested to 8ah and 5ah. 5 being half the rateing. if you don’t havea tester like so, https://www.amazon.com/gp/product/B07HB3XK7L/
you going to get junk batteries not know it. you would almost be wise to measure one of the batteries in your pack to make sure what ever 16-20ah lifepo4 you get is the same size. then run test to make sure it has the AH it promises
you could also upgrade to big boi batteries like it did with a custom battery cable, you would substitute lifepo4 in place of the lead acids, which i have also done but not posted yet. maybe i have pics on my phone already.
i have even bought one single 25v 150ah lifepo4 to upgrade this ^ very setup.