Which Inverter/Generator ?

[Shaun Witts]

I run a small (the smallest) Nespresso machine in my van. It's 1200W and I have a 1500W NDS pure sine wave inverter drawing from a 180A/h leisure battery topped, up by a 160W solar panel.

Exploria originally fitted a 2500W modified sine wave inverter, but this proved incompatible with the electronics on my Nespresso machine (& a De'Longhi Espresso from the house) and had to be replaced with the much more expensive NDS unit. TBH the eventual overall cost was too high just for a decent mug of coffee, but I had already commited part-way with the original inverter so felt I had to finish it properly.

With no EHU at Busfest, I was still able to make 4/5 mugs of coffee each day, though the inverter did beep what I assume was a low voltage warning first thing in the morning after the LED mood lighting had been on all evening, and the solar panel was facing away from the morning sun. It was fine later in the day.

 

[Onetimeonly]

Thanks @Shaun Witts, the coffee machine i have in mind is half the power of yours so hopefully should be fine

fingers crossed.

 

[travelvolts]

What type is your current battery?

 

[Onetimeonly]

What type is your current battery?

This is my current leisure battery @travelvolts

 

[travelvolts]

It's not a bad battery but I think you will need the engine running when you make coffee due to voltage sag. A lithium battery is the real answer or a pure lead AGM but either are pricey.

 

[Dellmassive]

a nice writeup on Redarc:

Inverter Current Draw - FAQs | REDARC Electronics

INVERTER CURRENT DRAW


How much current is drawn from the 12V (or 24V) battery when running a battery inverter?


Documented in this article is a common question relating to the inverter current draw and a breakdown of expectant voltage and efficiencies.



Question

How much current is drawn from the 12V (or 24V) battery when running a battery inverter?



Answer

The simple answer is- divide the load watts by 10 (20). E.g. For a load of 300 Watts, the current drawn from the battery would be:


300 ÷ 10 = 30 Amps (300 ÷ 20 = 15 Amps)



Notes:

• It is the actual load watts, not the inverter rating that counts. So a 1500W inverter with a 500 Watt load would be 50 (25) Amps, not 150 (75) Amps.The same inverter with a 1200 Watt load would draw 120 (60) Amps.



• For a quick idea of how long a battery will last without the alternator running, think of the load watts in terms of headlight watts-


How long will my battery last with an inverter load of 1000 Watts?



About as long as having 10 x 100W driving lights on. You know a normal car battery wont last long even with just 2 x 55W headlights and 4 x 5W park/tail lights- 130W total.



• For a more accurate calculation of battery current: Divide load watts by actual battery voltage, this will be in the range 12-14V (24-28V).

Then to allow for inverter efficiency, typically 85%, divide the figure by 0.85. Thus:


For a 300W load at 12V....300 ÷ 12 ÷ 0.85 = 29.4 Amps.


For a 300W load at 14V....300 ÷ 14 ÷ 0.85 = 25.2 Amps.


You can see the simple divide by 10 gives an easy "worst case" guide.

Similarly:


For a 300W load at 24V....300 ÷ 24 ÷ 0.85 = 14.7 Amps.


For a 300W load at 28V....300 ÷ 28 ÷ 0.85 = 12.6 Amps.


You can see the simple divide by 20 gives an easy "worst case" guide.



Note: Figures in brackets are for 24V systems.

 

[Dellmassive]

and:

(Looks like Redarc are using rebadged Cotek inverters)

Finding the right inverter for the job | REDARC Electronics


FINDING THE RIGHT POWER FOR THE JOB

Confused about which inverter you need for the job? See below for a guide. Refer to the appliance's power consumption placard to ensure the correct model inverter is selected.







350W

Capable of powering phone and camera chargers, CD players, GPS, computers, bi-pap machines.





700W

Same capabilities as 350w model Plus TV’s, and refrigerant recovery machines.





1000W

Same capabilities as 700w model Plus blenders and power tools.





1500W

Same capabilities as 1000w model Plus coffee makers and hairdryers.





2000W

Same capabilities as 1500w model Plus microwaves.





3000W

Same capabilities as 2000w model Plus irons, heaters and kettles.

 

[Nuttymike]

Hi I was wondering what size inverter I would need to run a 50 watt fridge?

 

[Spaghetti]

Is it not a 12v fridge? 50w seems very low for a 240v fridge. My Webasto 12v is 72w.

the start up current on a motor (fridge compressor) is many times the rated running load, and will trip out an inverter on the limit.

I had a 1000w inverter generator and it wouldn’t run my mains fridge as the start up current was so high.

 

[Pete C]

Which model fridge is it ?

Pete

 

[Nuttymike]

It's just a very small fridge my girlfriend brought from aldi ...she thinks I can just plug things in..lol

 

[Kev23]

In short, I’m looking to get 240v inverted fitted to the van. I’ll be getting a company to do this, but as I know nothing about these. What equipment do I need? 2nd battery etc?
many ideas of cost completed with fitting

 

[Pete C]

What sort of power (Watts) will you be drawing from it ?

Pete

 

[Kev23]

Not sure, basically running laptop and charging drone battery’s etc, maybe a kettle, I know nothing of these things or elecs, so forgive the lack of info

 

[Pummer67]

you can get a 12volt kettle and 12 volt chargers for the laptop and our drone will charge from 12volt. Why not get a small camping cooker for the kettle though and try everything through 12volt. If you really want a 240 volt kettle you will need to choose the right wattage one for the size of inverter. E.g. if you have a 2000watt inverter you can only have a 2kw kettle but the inverter will need the engine running. I would go gas for kettle and if you really want an inverter buy a smaller one for the laptop and bits. The larger wattage ones are huge.

 

[Kev23]

Thanks for the replies, never knew the engine would need to be running for the inverter, they could be a show stopper, why is nothing ever simple?

 

[Pummer67]

It wint need engine running for laptop and small things. Just high wattage appliances like a kettle, microwave or toaster.

 

[Pete C]

If you want hot water, then it’s easiest to get a portable gas burner.
Basically the more electrical power you need, the more expensive it gets.
If you intend charging stuff etc, then it’s best to get a 2nd battery, as this will ensure you don’t flatten your van Starter battery. This second battery needs charging, so you need a DC-DC charger for when you are driving.
You also need a suitably powerful inverter to give you 240v.

Your best bet is to speak to a decent vehicle electrician, who will ask the right questions before selling you something.

Pete

 

[Martin Gibson]

@Kev23 ,ask Martyn @travelvolts , he will advise and supply anything you need for this job

 

[Kev23]

@Kev23 ,ask Martyn @travelvolts , he will advise and supply anything you need for this job

would rather have someone do the job inc supply, but it’s getting a bit complicated and the expense may just not justify my needs.

appreciate the help though, thanks