Anyone managed a decent 12v setup for under £300 total? What did you actually spend?

Been trying to put together a proper working solar setup for my campervan on an absolute shoestring and I'm curious what others have managed. So far I've got a 100W panel off eBay for £65, a Renogy Wanderer 30A PWM controller (£28 from Amazon), and I'm eyeing up a 100Ah leisure battery from Tayna for around £85. That'd leave me roughly £120 for cabling, fusing, a battery monitor and whatever else I've inevitably forgotten.

The battery monitor is the bit I'm stuck on. I've seen the Victron BMV-712 recommended everywhere but that's £90 on its own which wrecks the budget. Has anyone used one of the cheap 500A shunt monitors off AliExpress or Amazon — the ones that are about £12-15? Wondering if they're accurate enough to actually trust or if I'd be throwing money away.

Also open to hearing if my component choices are a bit daft. The PWM vs MPPT debate did my head in for a bit but with just the one 100W panel and a 12v battery I figured PWM was fine and saved me about £20-25. Did anyone else go that route or do you reckon I've made a mistake there?

@LochSeeker mate I did the whole thing for £287 including a Fogstar 100Ah LiFePO4 (caught it on a flash sale), a Renogy 40A MPPT, and a secondhand Victron BMV-700 off eBay — the panel was the cheapest bit, which tells you everything about where the real money goes in these builds.

@LochSeeker done something similar for my static van. Ended up around £285 all in.

Went with a Renogy 100W panel (£89), Victron 75/15 MPPT (£65 used off Facebook Marketplace), and a Fogstar 100Ah LiFePO4 battery (£129 during one of their sales).

Tight but totally doable. A few tips:

• Facebook Marketplace is genuinely brilliant for Victron gear
• Fogstar do sales fairly regularly, worth waiting
• Don't skimp on the MPPT controller, cheap PWM ones are a false economy

Only thing I'd say is factor in cabling and fuses — easily another £20-30 that people forget. Blew my budget slightly because of that rookie mistake 😅

What controller were you going to go with? That's usually where people waste money on something rubbish.

Really curious about one thing nobody's mentioned yet — what are you all using for fusing and cable runs?

That's where my budget always creeps up unexpectedly. Proper ANL fuse holders, tinned marine cable, decent connectors... it adds £30-50 easy before you've even blinked.

Did my narrowboat setup last year and genuinely underestimated the BMS wiring side when I went with a Fogstar battery. Also — @BC_Boats did you factor in the MC4 connectors and entry gland for the panel cable? Because I always forget those fiddly bits until I'm stood in a car park somewhere!

Wondering if anyone's managed the £300 target including all the ancillaries rather than just the headline components? That's the real test isn't it 🤔

@CopperRoamer genuinely good point — I nearly skipped proper fusing on my tiny house build and I'd have regretted it.

Quick question for the thread though: does anyone have a rough breakdown of cable costs in their totals? I'm planning a van conversion and I'm wondering whether to factor in 16mm² for the battery-to-inverter run or whether most people are skimping on cable gauge and getting away with it on smaller setups?

Also — are people buying cable from somewhere like Tayna or just eBay? I've heard mixed things about eBay cable not being true to its stated gauge, which seems like it could be a real problem when you're fusing based on those specs.

@CopperRoamer raises something really important there. On my build I used a 30A blade fuse holder as close to the battery positive terminal as possible — picked up a pack of 10 holders for about £4 on Amazon. For cable I went with 6mm² for the main battery runs, sourced from a local auto-electrical place rather than eBay, which actually worked out cheaper per metre and I could see what I was buying.

The bit people often miss is fusing the panel-to-controller run as well, not just battery-to-loads. Caught me out first time round.

Total spent on fusing and decent cable was maybe £18, which feels like the best £18 in the whole build honestly. @PaddyGibson is right — it's the boring bit but skip it and you're asking for trouble.

@CopperRoamer good shout. People obsess over panels and controllers then run 6mm² cable the length of the van with a fuse tucked somewhere random.

On my motorhome I put the fuse as close to the battery positive terminal as physically possible — within 150mm ideally. That's the bit that matters. The run from there onwards is protected.

For a basic 100W setup you're not pulling huge current but don't skimp on the cable itself. Voltage drop on undersized cable will absolutely murder your efficiency, especially over longer runs. I use a voltage drop calculator before buying anything.

Inline ANL fuse holders from Amazon do the job fine — about £8. Tinned marine cable is worth the few extra quid if you can stretch to it.