Highland laddie
Well-Known Member
Hello everyone, I can apply ohms law to DC (just), however I am unsure as to the inverter wattage required to provide 230v @ 1.5 amps. Can the forum please help?
Inverter, how many watts for laptop?
- Thread starter Highland laddie
- Start date
sarabande
Well-Known Member
it is also possible to run a specific 12v car charging unit to a laptop without going up to 240v and then down to (?) 19v DC).
Ebay and other sources.
http://www.google.co.uk/search?q=eb....,cf.osb&fp=511c47e743c6c5d&biw=1024&bih=1134
If you need a small inverter for other items, then 300 Watt is about OK
Ebay and other sources.
http://www.google.co.uk/search?q=eb....,cf.osb&fp=511c47e743c6c5d&biw=1024&bih=1134
If you need a small inverter for other items, then 300 Watt is about OK
sailorman
Well-Known Member
i got one from maplins complete with a usb built in
Rigger Mortice
N/A
Hello everyone, I can apply ohms law to DC (just), however I am unsure as to the inverter wattage required to provide 230v @ 1.5 amps. Can the forum please help?
230v x 1.5 amps = 345 watts.
but 345 watts at 12 volts is 345 / 12 = 28.75 amps from your battery....and that assumes 100% efficiency.
RichardS
N/A
I think ours is 300W and that can run two laptops provided you don't start them both at the same time!
Richard
vyv_cox
Well-Known Member
I think there has been a thread on this not long ago, surprisingly a relatively large inverter could not cope with a laptop whose battery was well down. Mine is 600 watts and has no problem with it.
noelex
Well-Known Member
Most laptops use about a 90w adaptor. The consumption will be higher due to inefficiencies, but not over 300w.
My guess is the charger says 100-240v 1.5A. This mans the maximimum consumption will be 1.5A, but that is at 100v. If you run it from 240 v the consuption current will be lower. It will consume a maximum of about 150w. There is an inrush current, which can mean that the inverter needs to be a bit larger.
Plugging in the charger, then plugging it into the laptop will help. If you do this it will probably just run on with a flat battery from a 200w inverter. If you are prepared to leave the laptop off till the battery has some charge a 150w inverter should be fine, particularly if it has a higher surge rating.
My guess is the charger says 100-240v 1.5A. This mans the maximimum consumption will be 1.5A, but that is at 100v. If you run it from 240 v the consuption current will be lower. It will consume a maximum of about 150w. There is an inrush current, which can mean that the inverter needs to be a bit larger.
Plugging in the charger, then plugging it into the laptop will help. If you do this it will probably just run on with a flat battery from a 200w inverter. If you are prepared to leave the laptop off till the battery has some charge a 150w inverter should be fine, particularly if it has a higher surge rating.
temptress
Well-Known Member
Hello everyone, I can apply ohms law to DC (just), however I am unsure as to the inverter wattage required to provide 230v @ 1.5 amps. Can the forum please help?
I strongly recommend you use a 12v DC charger for your laptop. Get a good quality one for Maplins and you can run your laptop and have a USB charger available for other devices. IMO invertors should be avoided as much as possible.
GrahamM376
Well-Known Member
Problem with inverters is that some are advertised at their peak loading ie 700W whereas the constant is only 50% of that.
Our 350W (700peak) charges/runs laptop + TV at the same time OK or, SWMBOs small kitchen appliances.
Our 350W (700peak) charges/runs laptop + TV at the same time OK or, SWMBOs small kitchen appliances.
CreakyDecks
Well-Known Member
My laptop has a power consumption of about 75W. My daughter's netbook has a consumption of 5W and will run for 13 hours on its own batteries! Obviously it depends what you use the laptop for, but it might be worth considering getting a netbook, especially if you have access to wifi.
Highland laddie
Well-Known Member
Many thanks for advice, I didn't realise that a 19.5v supply could be obtained from 12V, this is much simpler and cheaper than a 230v inverter. Is the 19.5v charger in effect an inverter, or is other technology involved?
Regards Gerry
Regards Gerry
Rigger Mortice
N/A
Many thanks for advice, I didn't realise that a 19.5v supply could be obtained from 12V, this is much simpler and cheaper than a 230v inverter. Is the 19.5v charger in effect an inverter, or is other technology involved?
Regards Gerry
In effect, yes. But it will be a lot more efficient, so the drain on your batteries will be reduced.
Highland laddie
Well-Known Member
Cool
NickRobinson
Well-Known Member
I've tested several 150/300w inverters, with laptops mains psus and the clever adapter below which is 12/240 in with multiple dedicated tips for laptops.
http://www.ebay.co.uk/itm/Belkin-Un...Accessories_PowerSupplies&hash=item33738d1d4b
(no connection)
My ammeter gives broadly the same current for either, 1.5/2A.
Have the people who dislike inverters tested them themselves?
Nick
http://www.ebay.co.uk/itm/Belkin-Un...Accessories_PowerSupplies&hash=item33738d1d4b
(no connection)
My ammeter gives broadly the same current for either, 1.5/2A.
Have the people who dislike inverters tested them themselves?
Nick
Rigger Mortice
N/A
No, I haven't but I don't understand your figures. A 2 amp drain on your battery at 12 volts is 24 watts. Most laptops use a lot more than that.....but not necessarily all the time.
What exactly were you measuring?
Spyro
Well-Known Member
Many thanks for advice, I didn't realise that a 19.5v supply could be obtained from 12V, this is much simpler and cheaper than a 230v inverter. Is the 19.5v charger in effect an inverter, or is other technology involved?
Regards Gerry
It's a DC-DC converter. What laptop do you have? I've got an extra one that fits various panansonic toughbooks.
pagoda
Well-Known Member
I'm with Ian on this... there are several DC/DC converters available- which generally operate with more efficiency (and less noise) than inverters. They are also almost invariably smaller. Have a look on Ebay for DC/DC laptop power supplies. You will be pleasantly surprised
Graeme
noelex
Well-Known Member
The 12v converters typically use about 30% less power than using an inverter and 240v adapter. It does depend on the design and on the efficiency of the inverter.
The advantage of inverter is that it can used for other things such as charging camera batteries.
Amulet
Well-Known Member
DC to DC is the way to do it. I measured a 50% benefit over inverter. If in doubt, take the laptop and its mains charger to Maplins and get one of their geeks to tell you which "car charger" you need. I have used these for the last four laptops with no problem.
I also have "car chargers" for the three cameras and two iPhones we have aboard. Unless you want to run a 230 volt appliance you don't want to mess with inverters. I have never failed to find a source of car chargers for devices with built in batteries. It just requires a bit of googling.
I also have "car chargers" for the three cameras and two iPhones we have aboard. Unless you want to run a 230 volt appliance you don't want to mess with inverters. I have never failed to find a source of car chargers for devices with built in batteries. It just requires a bit of googling.
NickRobinson
Well-Known Member
Hi-
An AVO inserted in series between the battery and inverter or 12v adapter on 10A scale. A flat l/top battery would initially pull in 3a+ but would drop down to 1.5/2a. A 3yr old 85a/hr no name caravan battery would run it for 20 hrs (down to 11.8v- not recommended, I know.)
N
