Anyone know if a 200Ah lithium battery will run a small chest freezer overnight?

Running a small chest freezer off a 200Ah lithium (so roughly 2kWh usable at 100% DoD, though I'd cap it at 80% for longevity giving ~1.6kWh) is something I've been trying to work out for my shepherd's hut setup.

The freezer I'm looking at is a Shoreline 60L — rated at around 85W but obviously it cycles on and off rather than running continuously. From what I've read, a small chest freezer in decent ambient temperatures might average 30–50W over 24 hours, so roughly 0.3–0.5kWh per 24-hour period. Overnight being maybe 8–10 hours, that'd be somewhere between 100–200Wh in theory.

On paper that looks very achievable with a 200Ah bank, but I'm suspicious I'm missing something. A few things I'm uncertain about:

• Compressor start surge — does this cause any real issues with smaller lithium systems, or does the BMS handle it without drama?
• Ambient temperature — the hut can get quite warm in summer. Does that significantly push the duty cycle up?
• Inverter efficiency losses — I'm running 12V so I'd need a pure sine inverter. Are people factoring in maybe 10–15% loss on top?

I've got a Victron SmartSolar MPPT and a Fogstar Drift 200Ah battery already installed, so the hardware is there. Just want to sense-check before I commit to the freezer purchase.

Has anyone actually measured real-world consumption running something similar overnight rather than just going off the nameplate figures? Would love some logged data if anyone has it.

@ExPostie82 Depends entirely on the freezer's actual draw — my shepherd's hut runs a small chest freezer that cycles maybe 30-40Wh/hour in winter, so overnight (say 10hrs) is only 300-400Wh... your 1.6kWh budget is laughing at that. 😄

Key things people miss though:

• Ambient temperature massively affects compressor duty cycle
• How full it is (mass retains cold)
• Cheap chest freezers often have poor insulation = more cycling

Slap a Victron SmartShunt on it and actually measure what yours pulls over 24hrs before committing — guesswork here costs you battery health. Renogy do decent budget monitoring if Victron feels steep.

Short answer: almost certainly yes, but verify your specific freezer rather than trusting spec sheets, which are notoriously optimistic.

@ExPostie82 done this in my motorhome — chest freezers are sneaky because the duty cycle varies massively with ambient temp. Mine pulls about 60-80W when running but only cycles maybe 30-40% of the time in cooler weather, so actual overnight draw (say 8hrs) can be anywhere from 150Wh to 400Wh depending on how hot it is.

Your 1.6kWh headroom should be fine if you're not also running lights, charging devices etc. off the same bank simultaneously.

Worth getting a Victron SmartShunt or similar to actually measure what you're pulling — guessing gets expensive fast. Fogstar 200Ah is what I'm running and it handles overnight freezer duty no bother, but I've also got a decent solar setup recharging by midday.

What's the freezer model? Compressor efficiency varies a lot between manufacturers.

What ambient temp are you working with? That's what I'd want to nail down first before anything else.

I've got a Fogstar 200Ah in my static caravan and ran a small SilverCrest chest freezer through summer — on a warm night (18-20°C ambient) it was pulling around 0.8-1kWh overnight, well within the 1.6kWh budget. Dropped to nearly half that in winter.

Worth checking if your freezer has a decent energy rating — the difference between an A++ and a basic model is massive over 8 hours.

One thing nobody's mentioned: what's your solar situation for recharging next day? A 200Ah bank running a freezer 24/7 with limited solar recovery is a different problem entirely. What panels have you got?

Got a Fogstar 200Ah on my narrowboat running a small chest freezer — summer ambient in the engine room nearly killed my battery budget, winter it barely touches it. Stick a smart plug with energy monitoring on it for a week and you'll have your actual numbers rather than guessing from spec sheets that are about as trustworthy as a politician's expenses.