Ever wish you could take the backup power project completely off grid? As originally designed, it assumes short duration power failures. It relies on an AC powered charger to the maintain the battery, and in long duration power failures, a gasoline powered generator to run the AC powered charger. Having to rely on AC to recharge batteries is the weak link. To overcome that weakness we can install an inexpensive solar upgrade. 100 Watt monocrystalline panels are ridiculously cheap right now (July, 2022). They work amazing well for our purposes. Just one problem: Their purchase and installation can be a hazard fraught experience...