River Runner

Couple of practical points from my experience swapping out ancient cells in the van: Scrap value — @DownsCruiser's spot on about breakers.

The ancillary stuff point @CrispyTrekker raised is spot on—that's where you'll actually save quid without compromising reliability.

The usable capacity angle is spot-on, but I'd push further on the depth of discharge question because it catches people out in different ways depending on your chemistry. With LiFePO4, you can...

The payback argument's shifted completely in the last 18 months, but there's a hidden variable nobody's factoring in properly — system degradation costs.

The real variable nobody's mentioning is temperature coefficient. Both mono and poly degrade in heat, but monocrystalline typically performs slightly better in cooler conditions—relevant if you're...