Hi all,
I tried using a 150w inverter plugged into the clipsal 12v plug hole via a cigar lighter adapter. I tried to run a laptop off this but all I got was an audible beeping noise from the inverter. This I thought was an overload noise. I then plugged it into the cars lighter socket in the front and back of the car and it worked perfectly.
I tested the volts coming from the caravan 12v socket which was 12.40v and 14amps. The battery itself is a 4 days old 115amp halfords leisure battery.
Would the problem be the length of wiring from the 12v caravan plug to the caravan battery?
Just because the battery is 4 days old doesn't mean that it's fully charged as it could have been standing for months without being given a re-charge therefore I would check the battery voltage first because 12.4 volts means the battery is dead. You need a fully charged battery with maximum power to operate an inverter which would be at least 12.7 volts minimum.
I could rarely get my laptop to work off a 150w inverter either.
It would work if the laptop battery was fully charged and it would maintain the fully charged state, but running the laptop and charging the battery at the same time would always be a problem
Far better to use a 12v to Laptop power supply, these often have variable setting, and come with the different size connectors to suit most Laptops.
A lot cheaper to buy than an inverter and far more efficient, you just have to ensure that you have set the voltage correctly, 15, 17 upto 20v maybe depending on the Laptop.
Or better still get one that is Fixed voltage 12v upto whatever your Laptop requires, this type will often come with the correct size connector to fit your Laptop.
I have had a variable one for years, and it works a treat, but can run a little warm at times.
Quote: Originally posted by tango55 on 06/5/2015Just because the battery is 4 days old doesn't mean that it's fully charged as it could have been standing for months without being given a re-charge therefore I would check the battery voltage first because 12.4 volts means the battery is dead. You need a fully charged battery with maximum power to operate an inverter which would be at least 12.7 volts minimum.
The battery was charged when new (just to make sure) and we have used the 12v lights for an hour. The battery is currently kicking out 12.8v.
It could be the length of wire to the battery, and it could also be too thin which would also cause a voltage drop. To find out you'll have to measure the voltage at the battery and at the inverter and see if they are the same. Multi stranded wire is better than solid copper wire too.
Check that the socket is clean also and it's plugged in tightly.
With regard to checking a batteries state of charge you should measure the open circuit voltage after the battery has rested for at least 2 hours. A charged battery should read 12.6v.
There is a drop from 12.80 to 12.40 from the battery to the clipsal plug. So I am going to wire up a short lead from battery to cigar lighter and see the results.
I have also just purchased online, a 12v to laptop power supply.
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Topic: Inverter issue
