Inverters are fairly inefficient, as mentioned above a good starting point is approx double the intended load.
as an example a 100W light bulb actually pulls 140watts.
So your 1300watt machine may have been pulling in excess of 1800watts.
Thats a load of 151 amps from your battery. So you will have had 2 problems. The power exceeding the inverters capacity and pulling 151amps through a leisure battery designed for small loads so the voltage will have plummeted and the current draw increase further.
Pulling that load your going to want 10 batteries all joined.
Aren't there infusers etc for coffee where you pour boiling water onto coffee in a glass jug then press a handle down to make all the bits drop to the bottom. Tasted OK to me as a tea drinker.
Quote: Originally posted by upthecreek on 25/9/2017
Thanks to all. Looks like its back to instant coffee
Why?
In our van we have:
a filter jug; grounds into filter paper cone above then boiling water poured on. Good for more than 4 people.
a cafetiere, just for the 2 of us.
and a French Coffee Percolator that goes on the gas stove, if it just one of us.
I'm with LlaniDavis on this one and use a standard stove-top perculator.
I do like my coffee and this kit works very well.
Ground coffee in the top and water in the base reservoir, can't go wrong.
just going back to the inventer thing which covers more than coffee making..
a good lets say 110 ah leisure battery will quite easily delivery 100 amps of load for short periods of time..
the snag is at such loads there will always be a voltage drop.. mostly it wont matter but inverters seem to be set up to switch off when the imput voltage drops much below 12 volts..
connect one up directly to your car battery run the car engine and you will probably be able to run you coffee machine.. the car battery plus engine powered alternator should keep the voltage up high enough.. :)
My invertor claims to be 95% efficient so I'm not sure where a previous contributor said it would double the load.
I use my 300W invertor to drive a TV which is rated at 19w so I presumably am pulling about 20W from my battery. Been doing it for 3 years now without a problem. Never use hook up.
Your inverter probably claims to be UPTO 95% efficient. But have you tested it?
I have learned not to trust manufacturers claims. You may find that the voltage needs to be exactly 13.99951 volts to get that efficiency and it will only be that efficient for 0.001 seconds. When you start digging into spec sheets the caculator starts screaming for new batteries.
My 300W inverter is more efficient than my 600W one. But it still draws 140watts with a standard 100W lightbulb for its load.
When you said goto the pub for thge capuccino i thought of the McD advert.. Thats £9 WHAT!!!
Although i do not drink coffee, not unless i want a migraine anyway.
Quote: Originally posted by Grampian91 on 27/9/2017
Your inverter probably claims to be UPTO 95% efficient. But have you tested it?
I have learned not to trust manufacturers claims. You may find that the voltage needs to be exactly 13.99951 volts to get that efficiency and it will only be that efficient for 0.001 seconds. When you start digging into spec sheets the caculator starts screaming for new batteries.
My 300W inverter is more efficient than my 600W one. But it still draws 140watts with a standard 100W lightbulb for its load.
When you said goto the pub for thge capuccino i thought of the McD advert.. Thats £9 WHAT!!!
Although i do not drink coffee, not unless i want a migraine anyway.
I think it's time to bin your 300w inverter. I wouldn't be happy with that kind of efficiency. Our 18" LED back lit TV is rated at 35w and the inverter typically draws 1.6 amps (19.2w) from the battery. The discrepancy in ohms law is because of the fact the TV is set in power saving mode.
When I was looking at buying the inverter I wanted the most efficient one I could get, it's a Studer 200w model and was extremely expensive... Don't ask
Electricity is very good at producing motion, but very bad at producing heat. Couple this with the inefficiency of inverters, and you can see that running anything containing a heating element, via an inverter, off a leisure battery is a very bad idea.
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Topic: inverters
