Anyone else running a small 12v system entirely on secondhand kit? Share your setups and costs

So I've been putting together a little off-grid setup for my shed/workshop on an absolute shoestring and I'm dead chuffed with how far a modest budget has stretched. Started with a couple of pulled 200W panels off eBay for £35 the pair, wired into a secondhand Victron MPPT 75/15 I got for £40 from a Facebook Marketplace bloke who was upgrading his van build. Total panel and controller spend: £75.

Battery side I went with a reconditioned 110Ah leisure battery from a local caravan dealer for £45. Yeah I know, not lithium, not a Battle Born, not even close — but for running a few LED strips, charging tools, and the occasional laptop it's been absolutely fine. I keep an eye on it with a cheap battery monitor (£8 off Amazon) and I'm not hammering it below 50%. Been running six months now with no drama.

Grand total so far is somewhere around £140 for the whole lot, not counting a bit of cable I had knocking about anyway. I'm genuinely amazed it works as well as it does. The Victron was the real find — even secondhand that controller is leagues ahead of the cheap PWM units I'd been looking at new for similar money.

Has anyone else gone fully secondhand or reconditioned for their setup? Curious what people have managed to build for under £200, and whether anyone's had bad experiences with pulled panels or reconditioned batteries that I should be watching out for going forward.

GeorgeSmith97 | 47 posts

@DontPanic8 Nice one mate, love seeing this kind of thread! My workshop setup is almost entirely secondhand too. Grabbed a pair of 100Ah leisure batteries off Facebook Marketplace for £35 the pair - bloke had upgraded to lithium and just wanted shot of them. Tested fine with a load tester.

Found a 30A PWM controller at a car boot for £4, cheeky but it works. Two 100W panels came from a solar farm decommission sale up near Derbyshire - paid about £18 each.

Total outlay was well under £100 and it's been running LED lighting and a small radio for two years without drama.

Only tip I'd add - always load test secondhand batteries before committing, I've been caught out before with ones that look fine but have a dead cell hiding in there.

DorsetBoater | 203 posts

Brilliant thread this! Running a secondhand 12v system on my narrowboat so slightly different context but the principles are identical. Picked up four 100ah leisure batteries from a caravan breaker near Blandford Forum for £40 the lot - two were duff but the other two tested fine and have been going strong for 18 months now. Solar panels came from a Facebook Marketplace clearance lot, two 150w panels for £35. Biggest lesson I've learned: always test batteries under load before getting too excited about them, a cheap battery tester from Screwfix has saved me buying lemons more than once.

@DontPanic8 what are you using for charge control? I started with a cheap PWM controller but upgrading to a secondhand Victron MPPT made a noticeable difference to how much I'm actually getting into the batteries on cloudy days.