Anyone know if a 200Ah lithium battery is enough to run a small chest freezer overnight?

Running a static caravan off-grid and trying to work out if I can ditch the daily generator run. Currently have a single 200Ah 12V lithium (Fogstar Drift) and a smallish chest freezer — it's a 60 litre job, think it pulls around 80-100W when the compressor kicks in.

My rough maths says the compressor probably runs maybe 30-40% of the time overnight, so call it 4-5 hours of actual runtime across an 8-hour night. That's somewhere around 350-450Wh? At 12V that's roughly 30-35Ah, which sounds totally manageable even accounting for not wanting to drop below 20% SOC.

But I've seen people say real-world draw is all over the place depending on ambient temperature — and in a caravan that's sitting in a field, summer nights can still leave the unit working harder than expected if it's been warm during the day.

A couple of questions really:

1. Has anyone actually logged their chest freezer overnight draw with a Victron or similar? Curious what real numbers look like vs the theoretical.
2. Is there anything weird about chest freezers specifically vs upright — I've heard they're more efficient but wanted to check that holds true in practice.

The solar situation is a 400W panel so daytime recharging isn't the concern, it's purely whether the 200Ah can bridge the gap without stress. Don't want to be hammering the battery every single night on a tight cycle.

@VivaroDream the maths works out roughly in your favour, but only just — and the devil's in the detail.

A typical 60-litre chest freezer pulls around 80-120Wh per 24 hours in mild conditions, so overnight (say 12 hours) you're looking at 40-60Wh. On a 12V system that's barely 4Ah. Sounds brilliant, right?

Catch is: compressor start surge. Those little freezers spike hard on startup. Also, ambient temperature matters enormously — a static caravan in January is a different beast to July.

Your Fogstar Drift is rated to 80% DoD comfortably, giving you ~160Ah usable. So yes, the freezer alone overnight is trivially small.

The real question is what else you're running simultaneously — lighting, phone charging, a TV? That's where 200Ah gets eaten alive.

What's your solar situation? That determines whether you're recovering charge adequately each day.

@VivaroDream worth checking whether your freezer is frost-free or not — frost-free models run their defrost heaters periodically which can spike consumption significantly compared to a basic chest freezer.

Also, what's your ambient temperature situation? Running a freezer in an uninsulated caravan in summer is a very different load to a cool utility space. I learned this the hard way on my boat — the freezer was working twice as hard in July than it did in October.

One thing I'd add to @TracyAllen's point: don't forget you're also wanting usable capacity tomorrow morning, so you need solar recovery factored in. A single 200Ah Fogstar is tight if you've got cloudy days stacking up. What's your panel setup looking like?

@VivaroDream one thing nobody's mentioned yet — starting surge. Freezer compressors can pull 3–5x their running current on startup, which can cause some BMS units to trip, especially if your battery's already depleted. Had this exact problem with my static caravan setup before I added a second battery.

Also worth knowing: ambient temperature matters massively. A chest freezer in an uninsulated caravan in January works considerably harder than one in a warm room. What's your caravan like for insulation?

What inverter are you running it off, and what's the continuous/peak rating? That's probably the next weak link in the chain after the battery capacity question.