For those on a tight budget I noticed some very inexpensive DC to DC chargers on eBay.
I have a dc to dc charger to augment the solar and love it. The extra boost to the batteries really helped. The inverter has never shut down due to low voltage. And that’s with a smallish 200ah
battery. I noticed some very inexpensive chargers on eBay yesterday when surfing the energy stuff. For example this one is used but I’ve had good luck with used energy stuff: