I wouldn't use LiPo cells, especially consumer ones, for anything that stays on 24/7 and unattended in rural areas. LiFePo4 ones are safer and more durable alth

I wouldn't use LiPo cells, especially consumer ones, for anything that stays on 24/7 and unattended in rural areas. LiFePo4 ones are safer and more durable although for medium/low current solar powered devices with backup battery, Lead Acid might still be a viable, cheap and very safe choice. Unfortunately the author area isn't served by broadband, so he's forced to rely on mobile connectivity, which restricts the options wrt available router devices. I would have either used a (more costly) external DC powered (no internal battery) router supplied by a 12V battery and the solar panel, or modified the portable one to work only through external supply. Also, the author says the SD card in the Raspberry Pi developed errors. This is normal as SD cards are quite unreliable and prone to errors with time and use; I would have used a eMMC capable board, plus external disk with moderately aggressive spin down (to save power) for data storage.