Does anyone actually manage to run a 12v compressor fridge full-time on a small van solar setup?

I've been trying to get my head around whether a 50–60W compressor fridge (thinking the Alpicool C15 or similar) is genuinely viable as a permanent fixture in my Transit Custom conversion, running off a fairly modest solar setup. I've got a single 175W panel on the roof feeding a 100Ah lithium (a Fogstar Drift), with a Victron 75/15 MPPT. On paper it seems like it should work, but I keep second-guessing myself when the British weather gets involved.

The fridge apparently draws around 35–45Ah per day in moderate temperatures, which would eat up a serious chunk of my usable capacity if I'm parked up for more than a day or two without decent sun. I'm trying to figure out if people are genuinely living with this day-to-day in the UK, or whether most folks are supplementing with a B2B charger from the alternator to make it practical. I do commute in the van a few days a week, so the alternator option isn't totally out of the question.

Has anyone been running a similar setup through a UK winter and come out the other side happy with it? Would love to know what compromises you've had to make, or whether you just bit the bullet and went bigger on the battery bank.

Running one in my setup for about 8 months now — totally viable but the maths matters.

A 50W compressor fridge doesn't draw 50W constantly. Real-world duty cycle is roughly 30-50% depending on ambient temp, so call it 15-25Ah/day at 12v in summer, more in winter.

My advice:

• 200Ah LiFePO4 minimum (I use Fogstar Drift cells)
• 200W+ of panel
• Decent MPPT — Victron SmartSolar handles the charging properly

The Alpicool is decent but the Iceco units hold temp better in my experience. Fridge placement matters too — keep it out of direct sun and ventilated underneath.

Winter is where people get caught out. Shorter days + fridge working harder = you need buffer capacity. I dipped into 30% SoC a few times before I added a second panel.

Doable though, genuinely.

WFS_Camper | 847 posts

To add to what @DalesWanderer is getting at — ambient temperature is the variable most people underestimate. That fridge will cycle very differently parked in Scottish shade versus a sunny French campsite.

I'd strongly suggest logging your actual consumption over a week rather than trusting spec-sheet figures. My Iceco draws noticeably more in summer than winter, often 30-40% extra when it's really warm.

Also worth factoring in: lid-opening frequency matters more than people realise. Pre-chill everything before it goes in and you'll see real savings.

What's your battery capacity looking like? That's usually the limiting factor on smaller Transit Custom setups more than the solar input itself.

Great thread. To add to what @DalesWanderer is getting at — ambient temperature is the variable most people underestimate. That C15 might draw an average of 25–30Wh per hour on a cool Scottish morning, but park it in full sun in August and you're looking at considerably more. Insulation around the fridge makes a genuine difference too.

For a Transit Custom specifically, roof orientation and any shading from roof bars will affect your harvest more than people expect. I'd suggest sizing your panel array more generously than the "minimum viable" calculations suggest — 200W minimum, ideally 300W if you can fit it. Pair that with a decent 100Ah lithium and you'll be comfortable rather than anxious. Gel or AGM will work but you'll feel the pinch on overcast weeks.

Moorey13 | 312 posts

All good points above. One thing nobody's mentioned yet — insulation around the fridge matters nearly as much as the fridge itself. I spent weeks obsessing over panel wattage before realising I'd plonked my C15 right next to the engine bay bulkhead. Moved it to a better-ventilated spot with an air gap behind it and my daily draw dropped noticeably.

Also worth mentioning: the C15 specifically has a decent low-voltage cutoff, but I'd still recommend pairing it with a quality DC-DC charger from your alternator as a backup for prolonged cloudy stretches. Solar alone in a UK winter is genuinely humbling. 😅

What's your planned battery capacity @ForestLover? That's probably the next piece of the puzzle once you've settled on the fridge.

PaddyDavies | 203 posts

Been running a compressor fridge in my Transit for going on three years now — totally viable with the right setup.

What nobody's quite landed on yet is duty cycle varying so dramatically by season. Mine barely ticks over in winter but works considerably harder come July. Worth sizing your battery bank around those summer months rather than averaging it out.

I run a Fogstar Drift 100Ah lithium alongside two Renogy 175W panels on the roof, and honestly the fridge has never been the problem — it's when I add a kettle or laptop that things get interesting.

@Moorey13's point about insulation is spot on though — I lost weeks figuring that one out the hard way.

Welcome to the forum @ForestLover — the fact you're asking these questions before building rather than after puts you miles ahead of most of us!

IvyLes | 847 posts

Worth adding — placement makes a bigger difference than people think. Had mine tucked against the cab wall in the van and it was working way harder than it needed to. Moved it so there's airflow around the compressor end and consumption dropped noticeably.

Also on the solar side, don't underestimate winter. I'm on a Fogstar 100Ah lithium now with 200W of panels and it's... fine mostly, but a cloudy December week in the UK will have you nursing it a bit. A decent Victron MPPT wrings every last watt out of what little light there is, which genuinely helps.

@PaddyDavies three years is reassuring to hear — what's your battery setup like?

LisaKelly66 | 578 posts

Different context from a van but the principle's identical on my narrowboat — I've had a Dometic CFX3 35 running full-time for two years off a 200Ah Fogstar Drift lithium bank with two 175W panels. Mid-summer it barely notices the fridge exists. January through February though, when you're parked up under trees and the sun's gone by 2pm? That's where your battery capacity becomes the real conversation, not the solar.

@ForestLover — what's your planned battery size? That number matters far more than the panel wattage for working out whether a compressor fridge is genuinely viable as a permanent fixture rather than a fair-weather one.

SparkyGrafter | 64 posts

Curious whether anyone's tracked actual amp-hour draw over a full 24 hours rather than relying on the quoted wattage? On my boat I found the Dometic CFX3 was pulling noticeably more than the spec sheet suggested once ambient cabin temp crept up in summer.

Also — what's the minimum viable battery bank you'd pair with this realistically? I'm planning a tiny house build and considering whether 100Ah of Fogstar Drift LiFePO4 is enough headroom alongside a modest 200W Renogy panel, or whether I'm kidding myself.

JulieEvans | 312 posts

@SparkyGrafter great question — I logged mine with a Victron BMV-712 over a full week last summer. The C15 pulled between 28 and 45Ah per 24 hours depending on ambient temperature and how often I opened it. On a 200W panel with 100Ah of lithium, I was comfortably breaking even on sunny days, but two overcast days back-to-back left me sweating a bit. My honest advice: don't size your battery around best-case scenarios. What's your planned panel wattage and battery capacity, @ForestLover? That'll determine whether it's viable far more than the fridge spec itself.