Several years ago there were a few threads here talking about 220V inverters (to supply more than the cigarette-lighter-adapter-limited 120W).

Plenty of them show up on Amazon. Not a single one of those appears to be manufactured by a European company, and reviews tend to be skeptical.

Also, neither in the manuals that I downloaded for a couple of these products, nor their marketing materials, nor the discussions here, did I get clear whether these things (the ones that are not permanently hard-wired and installed into the car) are intended to be operated with the engine running, or whether they're intended for brief use purely on the battery's stored energy.

 

I'd like the option to use my car (2020 Octavia MkIII Scout, 2.0TDI 135kW) as an occasional generator out in the middle of nowhere, able to power some amount (a few hundreds Watts, maybe up to 1kW) of 220V plugged in stuff. Initially, the thought is just electronics (laptop, mobile phone charger) which can take fairly dirty power because they all have rather smart solid state transformer/adapters, but it would also be nice to be able to plug in, well, whatever, without having to worry about crap quality pseudo-sine wave output from a cheap, poorly regulated inverter. (The manual of one of the inverters actually warned against plugging certain things into it, to avoid damaging the _inverter_).

 

So, a couple of questions:

* Any of these inverters, which would be clamped on to the battery terminals, are they suitable for a modern Octavia, to be used with the car engine running so that its the car (and petrol/diesel) really providing the power? Or must they NOT be used with the engine running?

* Does anyone know of a truly quality brand of manufacture of these things that will produce clean, relatively pure sine wave output, and can be suitable for anything from simple AC-to-DC electric transformers to motor-driven things and reactive loads that are sensitive to the quality of their input power? 

many thanks,

Jay

 

Bestek and Kreiger are two well known brands.

 

I've got Bestek for laptop charging although that's pretty redundant now as I've moved onto tablet pc's as they're easier to use and lighter. 

 

Mine I think is a 300w one that plugs into the 12v socket, it works and did the job at the time, haven't used it in ages.

Hi @TheWanderer, thanks.  I'm curious, I thought that the cigarette lighter ports were limited to about 120W. Did you ever run that 300W inverter (from the cigarette lighter port) at over ~100W?

 

Also, although yes I see that Bestek is common, it still comes across as a Chinese-manufactured (yes, most things are actually made there, which can be ok) relatively "white label" brand (which often signals a problem for quality-sensitive products) - in the sense that searches for the brand primarily find Amazon and other generic online marketplaces, and although I didn't find it in a Google search I simply guessed bestek.com .. and got what looks like a typical Chinese white-label manufacturer's site listing their products, grand claims, insufficient technical information to trust.

 

In short, I am not left with a strong sense that it would be wise to plug this onto my car's battery terminals and to plug anything I cared about into it. And none of the ads nor the Bestek website explicitly says nor shows in pictures how the product should be connected to a car's battery. I worry that their reference to "car" relates _only_ to the (120W-or-so limited) cigarette lighter port mode of the products.

 

Isn't there any proven quality (German, British, American, Canadian, whatever) brand that makes these sorts of things?

 

Please note, I am NOT prejudiced against the Chinese nor about outsourced manufacturing (in my work life I've overseen business process outsourcing on four continents, and it can work great if the client company performs adequate oversight). What I am sensitive about is cheap crap that can't be relied upon.

 

Hm. KRIËGER seems to be a US-headquartered company. I'll look at their products.
Hm. I notice at least one of their products has the same warning about not plugging in certain types of products: "Do NOT plug in battery chargers for cordless power tools if the 
charger carries a warning that dangerous voltages are present at the battery terminals." I get it. It's not designed to handle a device that could actually feed power back to the inverter.

And "Certain chargers for small nickel-cadmium or nickel-metal-hydride batteries can be damaged if powered by this inverter. Two types of appliances are susceptible to damage: .. Cordless razors and toothbrushes that plug directly into an AC receptacle."

I'd prefer to buy more bullet-proof, more "it produces AC voltage, which should be consumable by whatever needs AC voltage" products when dealing with electricity!

(Got to give Kriëger credit, though; their manual makes these myriad warnings far more clear by explaining how and why it all works that way, than does the Bestek manual).

 

Also, I am still looking for something decidedly beyond what can be plugged into a cigarette lighter port (higher consistent wattage), and still am trying to understand whether modern cars (which have enormously more complex electrical systems that than stuff on which I did my own minor maintenance 30 years ago...) actually get along ok with a piggybacked external load like a 400W, 500W, 1000W, etc inverter would represent.
Hm. The Kriëger manual has plenty of detail of how to connect the inverter to a battery, or a bank of batteries .. and nowhere is a battery-that-is-actually-installed-in-a-car mentioned.

Which makes me think that these things are absolutely NOT intended to provide continuous high wattage from a car's electrical system as it is being energized by an alternator!

 

thanks again,

  

4 hours ago, TheWanderer said:

Bestek and Kreiger are two well known brands.

 

I've got Bestek for laptop charging although that's pretty redundant now as I've moved onto tablet pc's as they're easier to use and lighter. 

 

Mine I think is a 300w one that plugs into the 12v socket, it works and did the job at the time, haven't used it in ages.

 

This is the one that I've got. It's now £31. It's not sine wave, I don't know what that is even, I'm guessing it's something to do with the current flow

Edited 21 August, 20214 yr by TheWanderer

Thanks @TheWanderer.  I suspect that the "300W" rating is .. aspirational. If you plugged a 300W continuous draw load into this (say, a 300W old fashioned incandescent light bulb) I'm pretty sure you'd either trip the circuit breaker (if there is one) in the inverter, or a fuse in the car. The models that can handle continuous higher loads would have to be wired in to the car's electrical system.

About Modified Sine Wave or Pure Sine Wave, you can read about it here: https://gopowerfleet.com/pure-vs-modified-sine-wave-inverters-whatss-difference

The short is that modified since wave inverters are good only for not-particularly-sensitive loads (such as transformers with rectifiers) that can eat "dirty" power. Motors, and anything that expects the power to provide highly consistent wave form (old fashioned AC-plugged-in electric clocks for example) either won't function well or might be damaged by being supplied with modified sine wave power.

 

I'm afraid that I don't know the best thing to do would be visit bestek website for more details. 

 

I'm not great with technical issues. 

Hi,

 

try these people, very big in the marine world. I had one on my boat though it was a charger/inverter but was great.

 

Inverters - Victron Energy

 

John

I got an answer from Krieger Manufacturing that clearly and explicitly says that people DO use their inverters, wired directly onto the battery terminals, with the car engine running, to provide the full power of the alternator to the inverter. They also indicated that people use one-or-more batteries, connected to solar chargers, connected to their inverters. They commented that the reason their documentation talks about using the batteries (but doesn't explicitly mention doing it with the battery still connected to the car itself) is only in order to maximize the current available to the inverter. 

 

Victron also answered me. I truly don't understand the answer that I received to the question of whether modern, complicated car electrical systems would somehow have a problem with an inverter drawing from the battery terminals while the battery remains connected to the car and the car engine running. The reply text was:

Quote

 

When connected directly on the battery the system doesn’t see the extra load.

As this can drain the battery this isn’t done normally, so then a second battery is added

 

 

That said, they also went on to say "yes, then that's an option" to my follow-up question which asked (putting aside the "could a modern, complicated car's electrical system be somehow incompatible with this) my idea is to use the car as a kind of generator (so the fuel tank, engine, and alternator would power the inverter).

So I guess Victron also is saying that this should work.

 

I'd still like to get an answer from a Skoda/VW group electrical system expert just to confirm that the load the inverter would place on the battery/ alternator being connected to the battery, in the car, car running, would NOT cause some kind of problem...

 

-Jay