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

Running a small chest freezer overnight is something I've been trying to work out for my own setup, so curious what others think here.

I've got a 200Ah LiFePO4 (Fogstar Drift 12V) paired with a 400W solar array, but obviously overnight there's no generation coming in. My freezer is a Shoreline 60L rated at roughly 60W, though I know compressor-based appliances don't draw continuously — they cycle on and off.

From my rough maths:

• Assume ~30–40% duty cycle overnight (say 8 hours)
• That works out to maybe 1.5–2kWh consumed
• A 200Ah/12V battery holds ~2.4kWh usable (assuming 80% DoD on LiFePO4)

So on paper it should be fine, but I'm wondering whether:

1. Ambient temperature affects compressor duty cycle significantly — in a cold British garage in October, is it actually drawing less or more?
2. Whether the inverter efficiency losses are eating into my margins more than I'm accounting for (running through a Victron Phoenix 12/375)
3. Whether 80% DoD repeatedly overnight is going to stress the cells long-term, or whether I should be targeting 50% DoD and sizing up my battery bank

I haven't actually deployed this yet — still commissioning the system — so I don't have real-world figures to share yet. Would genuinely welcome data from anyone who's monitored their freezer consumption with a proper meter rather than just going off nameplate ratings, as I suspect real-world draw varies quite a lot between units.

Has anyone done this with a similarly sized bank and lived to tell the tale?

@SueThompson short answer: yes, probably. Long answer: depends how warm your garage is and whether your freezer fancies working overtime 😄

A small chest freezer typically pulls 30–60W running average (duty cycle included), so overnight (say 8–10hrs) you're looking at 25–50Ah consumed. Your

@SueThompson depends heavily on what "overnight" means to you and how efficient that freezer actually is. Most small chest freezers pull 80-150W when running but only cycle maybe 30-40% of the time in a cool space — so realistically 1-2kWh per night.

Your 200Ah Fogstar at 12V is ~2.4kWh usable (assuming you're not hammering it below 20% SOC). It'll probably cope, but barely, with nothing left for morning.

What I'd actually worry about is your inverter efficiency eating into that margin. Running a compressor through a cheap inverter is wasteful. What inverter are you using?

Also — Fogstar Drift is a decent battery but make sure your BMS settings are dialled in properly before you trust it with overnight loads unsupervised.

Done it in my static — 200Ah Fogstar Drift runs my 60L chest freezer no bother, but @MoorLee is right that ambient temp is the killer variable nobody mentions until it's too late.

Rule of thumb: a decent small chest freezer in a cool space pulls maybe 100–150Wh per day, so 200Ah @ 12V = ~2400Wh usable (at 80% DoD) — you're laughing even with a dodgy fridge that runs hot.

Where people come unstuck is running it during a heatwave in a poorly ventilated van with the coils buried against the wall. Seen grown men cry over warm ice cream.

Add a Victron BMV-712 so you actually know your state of charge rather than guessing, because "I think it's fine" is how you kill a £300 battery.

What @Rob1963 said tracks with my experience. I've got a similar setup in my shepherd's hut — 200Ah LiFePO4 running a small chest freezer and it's genuinely fine overnight, but I'd say insulation quality of the freezer itself matters as much as ambient temp. Mine's a cheapo unit and it cycles way more than it should because the lid seal is mediocre.

Also worth checking your actual overnight draw with a basic energy monitor before committing — I was convinced mine was pulling around 30-40W average but it was actually closer to 55W once summer hit and the hut warmed up. That changes the maths a fair bit.

If you're only discharging to 80% DOD to keep the Fogstar happy long-term, factor that into your headroom calculations.