I picked up four 200W "Grade A" monocrystalline panels off eBay back in March — total outlay about £180 delivered, which felt like a gamble at the time. Paired them with a Victron SmartSolar 100/30 that I already had sitting in the shed. The setup is on my static caravan up in the Dales, so it's not exactly the Sahara up here.
Honestly the results have surprised me a bit. On a decent day in June I was seeing around 22-23A coming through, which isn't miles off what the maths would suggest for 800W into a 24V system. The panels are wired 2S2P if that matters. Victron Connect shows everything looking fairly normal — absorption, float, the usual cycle.
What I'm less sure about is whether these cheap panels will hold up long-term. I've no idea what the actual cell quality is like under the hood, and I'm a bit suspicious the rated wattage might be optimistic. Has anyone done any proper side-by-side comparisons between budget eBay panels and branded stuff like Risen or JA Solar? Would be good to know if I'm worrying over nothing or if I should expect a noticeable drop-off within a year or two.
