Hooking a champion inverter generator to Sungoldpower inverter to charge batteries?

Been thinking about this exact setup actually — I'm running a Sungoldpower 3000W inverter/charger in my van build and occasionally wonder about pairing it with a generator for those extended cloudy spells when the solar just isn't cutting it.

The main thing I'd want to know before committing to a Champion is whether the AC output is clean enough. Sungoldpower units can be a bit fussy about the waveform they're accepting on the AC input side. Anyone had issues with the charger stage throwing faults when hooked up to a budget generator?

A few specific questions I'd throw out there:

• What's the minimum wattage Champion you'd recommend for a 3000W inverter/charger without the generator struggling under load?
• Does the inverter's transfer switch handle the handover cleanly, or does it cause any hiccups?
• Has anyone actually measured the THD on a Champion's output — I've seen mixed reports online

For context, I'm charging a 200Ah Fogstar Drift lithium bank, so the charger would be pulling a decent current at the bulk stage. My concern is the generator hunting or surging under that kind of sustained load.

Victron gear obviously plays better with generators in general but that's a different price bracket entirely. Curious whether anyone's made this specific combination work reliably in a real-world scenario rather than just a bench test.

@LDVNomad done something similar with my static caravan setup — I use a Sungoldpower 3000W paired with a petrol genny for backup charging when solar falls short in winter.

Main thing to watch: set the input current limit low on the Sungoldpower (I run mine at about 10A). Champion generators don't love being hammered at full load continuously, and the inverter/charger will absolutely try to pull maximum amps if you let it.

Also worth checking your generator produces clean enough sine wave output — some cheaper units cause the charger to throw faults. Proper inverter generators (even the budget Champion ones) are usually fine for this.

My Fogstar LiFePO4 batteries charge perfectly well through this combo. Just don't expect fast charging — treat it as steady trickle top-up rather than rapid charging and you'll have no issues.

@LDVNomad done this exact thing on my static caravan. One thing nobody mentions — generator output quality matters a lot. Cheap gennys put out dirty AC and some inverter/chargers get proper moody about it.

Champion's AVR units are usually fine but check your Sungoldpower's input voltage tolerance first. Mine threw fits until I dialled the genny down to about 80% load before connecting.

Also worth knowing — most of these Chinese inverter/chargers want to see the generator fully warmed up and stabilised before it'll accept the charge input. Caught me out first time, thought the unit was broken.

Victron stuff handles generator quirks better in my experience but costs triple. If you're committed to the Sungoldpower just test it carefully before relying on it in genuinely bad weather.

@ZFS_OffGrid makes a good point on output quality. Worth adding — inverter generators (like the Champion ones) produce much cleaner sine wave output than conventional open-frame gennies, which matters a lot for the Sungoldpower's charger circuit.

On my boat I've dialled the input current limit right down on the Victron side (Sungoldpower has similar settings) — stops the generator getting hammered at startup and hunting under load. Usually set mine to about 80% of the genny's rated output max.

Also check your transfer switch timing settings if the unit has them. Some Sungoldpowers are a bit twitchy about accepting generator input if the frequency stabilises slowly on startup. Give the genny 30 seconds to warm up before it sees the load.