Lithium batteries are a game changer!
You can use 90% of the rated capacity compared to just 50-60% of agm gel batteries. So they were right in suggesting 50-60 amp Hr lithium battery, which is so light compared to your agm. Go a little bigger if it won’t break the budget.
You just need a compatible charger for lithium also.
Hope this helps, heaps of info on YouTube!
