Does anyone know if a 200Ah lithium battery can run a small chest freezer overnight?

Running a small chest freezer in my garden office overnight is something I'm trying to work out whether it's feasible before I commit to buying.

The freezer I'm looking at is a 60L chest freezer, rated at around 90W but obviously it doesn't run continuously — it cycles on and off. From what I've read the actual consumption is somewhere in the region of 0.5–1kWh per 24 hours depending on ambient temperature and how full it is.

My current setup is a 200Ah lithium (Fogstar Drift 12V) with a modest solar array, so overnight I'd purely be drawing from stored capacity. Using the 80% usable DoD rule that gives me roughly 160Ah, or around 1.92kWh at 12V before I start worrying about damaging the battery.

So on paper it looks like it should be fine, but I'm wondering if anyone has actually done this in practice? A few things I'm not sure about:

• Does a freezer's compressor startup draw cause any issues with a typical inverter (I've got a Victron Phoenix 12/1200)?
• Does overnight temperature in an unheated space significantly affect how hard the freezer has to work, or does cooler ambient air actually help it?
• Is 200Ah actually tight, or is there comfortable headroom here?

The office isn't connected to mains so I can't just run an extension lead. Solar replenishment during the day should cover it but I want to make sure I'm not in a situation where I'm repeatedly hitting low state of charge by morning.

Has anyone run something similar long-term and noticed any unexpected issues?

@Bomber short answer: yes, probably, but the maths matters more than the headline capacity figure.

A typical 60L chest freezer draws around 30–45W continuously but compressors cycle, so real-world consumption is closer to 0.4–0.6kWh per 24 hours in a temperate UK location. Overnight (say 8 hours) that's roughly 130–200Wh.

A 200Ah lithium at 12V gives you ~2.4kWh usable (assuming 100% DoD on LiFePO4, though I'd target 80%). You're nowhere near stressing it overnight.

Bigger considerations:

• Compressor startup surge — make sure your inverter handles it (mine's a Victron MultiPlus, no issues)
• Ambient temperature in your garden office — freezers work harder in summer
• How you're recharging the battery next day

What inverter are you running? That's often the weak link, not the battery.

@Bomber the duty cycle is the key variable here. A 60L chest freezer might draw 80–100W when the compressor runs, but it's not running constantly — typically 25–40% duty cycle depending on ambient temperature and how full it is.

Worth checking the actual wattage on the label rather than relying on the listed daily kWh figure, which assumes mains conditions.

One thing I'd add: starting surge. Some inverters struggle with compressor start-up. Make sure whatever inverter you're using has adequate surge rating — I had issues with mine on the static caravan until I checked the peak draw rather than just the running watts.

Also, are you pairing the 200Ah with solar? Overnight alone is tight but manageable; without daytime recharge you'll chew through your usable capacity quickly.

@Bomber one thing worth adding to what @FormerMechanic14 and @BlownFuse have said — ambient temperature makes a massive difference to duty cycle. A freezer working hard in a warm garden office will cycle far more frequently than one in a cool shed.

Also worth checking whether your 200Ah battery is genuinely usable capacity. Lithium gives you around 80–100% usable, so you're looking at roughly 160–200Ah in practice. What's the inverter situation — pure sine wave? Some compressor freezers are fussy about modified sine.

I'd recommend logging actual consumption with something like a Victron Battery Monitor or even a basic plug-in energy meter first if you can test mains draw before going off-grid. Gives you real numbers rather than spec-sheet estimates.

Good points from @FormerMechanic14, @BlownFuse, and @BevJackson64 already covering the essentials.

One thing nobody's mentioned yet: lithium DoD matters here. A 200Ah LiFePO4 (say, a Fogstar Drift or similar) gives you roughly 190Ah usable at 12V — around 2.2kWh. That's workable overnight for a well-insulated chest freezer, but only if you're not relying on solar recharge to compensate next day.

From my cabin setup, I'd also flag the inverter efficiency loss — typically 10–15% overhead — which your freezer's rated wattage won't account for.

More critically: what's your battery management situation? A naked 200Ah cell without a quality BMS protecting against low-voltage cutoff could damage the pack if the freezer runs longer than expected. Victron's BMV-712 monitoring is worth the investment just to understand actual overnight draw before committing to a permanent setup.