Anyone else running a small inverter generator as backup alongside their solar setup? Worth it or overkill?

Been debating this for a while and finally pulled the trigger on a Honda EU22i last month. Paid about £950 for it from a dealer near Coventry. The idea was to have something to fall back on during those grim January weeks when the panels are barely producing 10-15% of their rated output and the 200Ah lithium bank is struggling to keep up with even basic loads — fridge, a few lights, charging laptops.

Honestly, it's been a revelation. Ran it for about 2 hours yesterday afternoon, chucked roughly 40Ah back into the batteries via a Victron IP22 30A charger, and the thing was whisper quiet compared to the old Chinese genny I had before. Fuel consumption seems to be around 0.5 litres per hour at the loads I'm running, so a full 4.1L tank gets me a decent chunk of top-up time without constant babysitting.

My main question is around automation — has anyone wired up an automatic start relay so the genny kicks in when battery SOC drops below a set threshold? I know the Honda's got a choke to deal with, so a fully automatic cold start seems tricky. Wondering if a manual relay that just cuts in the charger once you've started it manually would be a simpler and more reliable middle ground.

SolarPaul | ⭐⭐⭐ Senior Member | Posts: 847

Good shout @DriftMaster, the EU22i is a cracking bit of kit. I run an older EU20i alongside my 4kWh battery bank and honestly it's earned its keep several times over, particularly through last winter when we had that extended grey spell in January.

The key thing I've found is not treating it as a regular crutch - if you're firing it up every overcast day you're probably undersized on panels or storage. But for genuine extended bad weather it's brilliant peace of mind.

Worth investing in a decent automatic transfer switch if you haven't already, makes the whole thing seamless. Also keep the carb clean and run it under load occasionally even when you don't need it - sitting idle for months is what kills these engines.

£950 sounds about right for a dealer purchase with warranty. 👍

AmyChapman89 | ⭐⭐ Member | Posts: 234

Running mine on the narrowboat and it's basically the fourth crew member — complains less than the other three and actually produces something useful.

GoldenMaker | ⭐⭐ Member | Posts: 312

Had a Yamaha EF2200iS running alongside my Victron system for about two years now. Feeds straight into the Multiplus via the AC-in — Victron handles the handoff beautifully, barely notice the switch.

For EV charging it's basically useless on its own obviously, but it'll top up my Fogstar batteries overnight which then trickle into the car the next day. Bit of a faff but works in a pinch.

One thing I'd flag — inverter generators are not all equal on THD. Victron can be fussy. Honda and Yamaha are generally fine but I've heard of cheaper units causing grief with sensitive kit.

Worth every penny for those week-long grey stretches in winter when the panels are producing next to nowt.

HannahDavies85 | ⭐⭐ Member | Posts: 156

Got a Honda EU22i on the van and the narrowboat — basically my most committed relationship at this point. The real game-changer nobody mentions is pairing it with a Victron Multiplus so it charges the Fogstar lithiums properly rather than just chucking amps at them randomly. November through January in the UK, solar's about as useful as a chocolate teapot, so the generator earns its keep those three months and sits pretty the rest of the year. £950 sounds steep until your Victron MPPT is reading 4W at 2pm on a grey Tuesday in Shropshire.

TimTaylor | ⭐⭐⭐ Member | Posts: 487

Good timing on this thread — just been through a proper grim fortnight of November cloud cover up here in the Pennines and the EU22i earned its keep every single day.

One thing worth mentioning that I don't see discussed enough: keep a log of your runtime hours. Honda recommend valve clearance checks around the 300-hour mark and it's easy to lose track. I use a cheap Hobbs meter wired in — about £12 off eBay — saves any guesswork.

Also @GoldenMaker is right about the Victron integration — if you're running a SmartShunt you can set charge current limits remotely which stops the genny working harder than it needs to. Cuts fuel consumption noticeably once you dial it in properly.

@DriftMaster — £950 for the EU22i sounds about right these days. Solid purchase.

KentBoater | ⭐⭐⭐ Member | Posts: 743

Running an EU22i alongside a 400Ah Fogstar lithium bank and 600W of solar here — the combo is genuinely hard to beat once you've got it dialled in properly.

The bit nobody mentions: generator runtime drops dramatically when you're bulk charging lithium vs AGM. My Victron Multiplus will hammer that Honda at 1600W+ during bulk, which is fine, but the moment absorption kicks in and current tapers off you're essentially burning fuel for diminishing returns.

Worth setting a custom charge ceiling on your Victron (around 80-90%) and letting solar finish the job. Cuts runtime roughly in half once you get the sequencing right.

@TimTaylor — November is exactly when you find out whether your setup is properly sized or just optimistically sized. Mine failed that test embarrassingly in 2022, hence the generator purchase!

JasonMoore | ⭐⭐ Member | Posts: 203

Got a smaller Honda EU20i on the tiny house setup and honestly it earns its keep every winter. What I'd add that nobody's mentioned yet — pair it with a decent automatic transfer switch or let your Victron MultiPlus handle the switchover. Makes the whole thing seamless rather than you scrambling to plug things in manually when the bank dips. Also worth running it under decent load when you do fire it up, not just ticking over — keeps the internals happy long-term.