Anyone know if a 200Ah lithium battery will handle a 2kW inverter or is that pushing it?

Running a similar setup in my van and been wondering the same thing tbh.

Got a Fogstar Drift 200Ah sat under the bed and I'm looking at picking up a cheap 2kW inverter for the occasional power tool use. Maths seems fine on paper — 200Ah at 12V is 2.4kWh, and a 2kW load would drain it in just over an hour — but it's the discharge rate I keep second-guessing myself on.

The Fogstar is rated at 1C continuous, so theoretically it can handle 200A draw, which at 12V gives you 2.4kW. So a 2kW inverter should be within spec, right? But that's cutting it close when you factor in inverter inefficiency (usually 85-90%), so real-world draw from the battery could nudge toward 230A+.

Few things I'm not sure about:

• Does running close to the 1C limit regularly cause long-term degradation?
• Worth going 24V to halve the current draw instead?
• Anyone actually running a 2kW inverter off a single 200Ah 12V lithium in practice?

My use case is maybe 20-30 mins of use at a time, not sustained hours. Feels like it should be fine but don't want to cook the BMS or void anything before I've even got the van finished 😅

Hey @ThingamyBob62 - short answer is yes, it'll handle it, but with caveats.

A 2kW inverter at full load draws roughly 170A at 12V, which is going to hammer that battery pretty hard. The Fogstar Drift is rated at 1C continuous discharge (200A), so you're technically within spec, but you're right at the limit with inverter inefficiency factored in.

For occasional use - kettle, power tools, that sort of thing - you'll be absolutely fine. Where it gets dicey is sustained high loads. Running something like a hair dryer flat out for 20 minutes will stress the battery and the BMS may well cut out.

My suggestion would be checking what your actual loads are realistically. If most things are under 1kW and the 2kW is just for peaks, crack on. Just make sure your wiring and fusing are rated accordingly - that's often the overlooked bit.

@ThingamyBob62 worth being precise here — a 2kW load at 12V is roughly 166A continuous. The Fogstar Drift 200Ah has a 1C discharge rating, so that's 200A max. You're cutting it fine.

Bigger concern for me is your cable run and fusing. Most cheap inverters come with undersized cables that'll drop voltage before the battery even breaks a sweat. I run a Victron MultiPlus in my cabin and the cabling cost nearly as much as the inverter itself.

Also — what's your actual use case? 2kW peak or sustained? If it's just occasional kettle use you'll likely be fine. Sustained loads are a different story entirely.

@ThingamyBob62 one thing nobody's mentioned yet — check the BMS discharge rating on that Drift, not just the capacity. Pretty sure it's rated 200A continuous which means you're cutting it very fine at full 2kW load.

In practice a 2kW inverter rarely hits its ceiling — kettle, toaster etc. spike hard then back off. But I'd still be wary of sustained loads.

Running a similar setup myself (albeit 24V which makes the maths friendlier). At 12V you've got almost no headroom for cable losses before the BMS trips out on you.

If you're committed to 12V, keep cable runs as short as physically possible and use proper tinned marine cable. Voltage drop will hurt you before the battery does.

@MarineGaz beat me to the BMS point, so I'll add the practical angle nobody's touched yet — cable sizing and fusing.

Run the numbers on that 166A continuous draw and you'll realise your cabling becomes the weak link faster than the battery will. I learned this the hard way running a 1.5kW load through undersized 35mm² cable — voltage drop ate my inverter efficiency alive.

For a genuine 2kW setup at 12V you're really looking at 50mm² minimum for any run longer than about a metre, with an appropriately rated ANL fuse sat as close to the positive terminal as physically possible.

That Fogstar Drift is a capable battery — but it'll only perform as well as the weakest link in the circuit lets it.