Member Since: 03 Jan 2006
Location: Romiley
Posts: 13710
Nikkai 300W Inverter
Saw these in Maplins at lunchtime for £30 (reduced by a tenner) - it comes with both Cigarette Lighter and battery grip leads
Anyone else got one? Worth getting, in the absence of anything else? Really need to make my mind up before tomorrow afternoon.... 8)Steve N | 21MY Defender | 08MY Discovery 3 (history) | 06MY Discovery 3 (ancient history)
8th Mar 2007 1:31 pm
freebie2disco
Member Since: 01 Jan 2007
Location: wantage
Posts: 334
I use one for running the laptop in the car for memory map. Have used it for charging phone's game etc when away from home. Have also used for charging a cordless drill. Handy when you need it.
I haven't got my head around these yet. If it's 300w at 240v that's only 1.25Amps, but if it's 300w@12v it can deal with 25Amps. Anyone able to shed any light on this?I know it's not considered "kind" to say no these days, but no. Just no, ok? And if it's not ok, still no.
8th Mar 2007 1:39 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 73132
Power (W) = voltage x amps! Hence Amps = Power/Voltage. Easypeasy lemon squeezy.
8th Mar 2007 1:46 pm
SN
Member Since: 03 Jan 2006
Location: Romiley
Posts: 13710
If my memory of electrical engineering is correct, I don't think you're far wrong BUT AC is a funny beast and the sums aren't quite the same as DC - I'm looking at this because my laptop powerpack kicks out 19.5V at 3.34 AmpsSteve N | 21MY Defender | 08MY Discovery 3 (history) | 06MY Discovery 3 (ancient history)
Yeah, got all that (hence the numbers in my post) but what I'm not clear on is, if they advertise it as a 300w inverter is that 300w at input voltage or 300w at output voltage?
'snot much good if it only has a miserly 300w at 240vI know it's not considered "kind" to say no these days, but no. Just no, ok? And if it's not ok, still no.
8th Mar 2007 1:54 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 73132
That was from my O & A Level physics (1979 & 1981 respectively) so I was quite impressed I actually remembered it!
8th Mar 2007 1:55 pm
freebie2disco
Member Since: 01 Jan 2007
Location: wantage
Posts: 334
kind of depends what you want it for. There are heavy duty ones available for more robust equipment but for charging stuff or running laptops its fine.
8th Mar 2007 1:56 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 73132
Bring it at the weekend, we'll soon get the gubbins out of it to have a look! Just don't let DG think it is a min waffle board.
8th Mar 2007 1:57 pm
freebie2disco
Member Since: 01 Jan 2007
Location: wantage
Posts: 334
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26779
I think it will do your laptop just fine. It will draw quite heavily on the vehicle electrics though. I remember using one in my 2a, and it actually overtook the dynamo and flattened the battery whilst I was driving
8th Mar 2007 2:02 pm
SN
Member Since: 03 Jan 2006
Location: Romiley
Posts: 13710
My Dell laptop's only got a 2hr life on battery - and I want to use it for video at the weekend - since the camera blows away about a Gigabyte every hour then perhaps I can manage without.... Steve N | 21MY Defender | 08MY Discovery 3 (history) | 06MY Discovery 3 (ancient history)
8th Mar 2007 2:05 pm
bkehoe
Member Since: 24 Feb 2006
Location: Wexford
Posts: 1481
It would be 300W max output. It would probably consume more than 300W as it wouldn't be 100% efficient. AC is more complicated than DC, things like power factor - the type of load makes a difference, e.g. inductive (motors), so it isn't as simple as voltage times current. But I wouldn't worry about it for something simple like a laptop - probably well under 100W rated anyway.
What I'd be more worried about is if your laptop PSU will work properly with the power coming from the inverter. Cheap inverters don't produce a proper sine wave, and some sensitive power supplies could freak out when they see this and refuse to work or trip out the inverter. So ideallly you want an inverter that produces a pure sine wave - then you're pretty much guaranteed it'll work with anything.
But for £30, it'd probably be worth getting it just to see if your laptop works fine with it - i'm sure you could bring it back if it didnt.IE - 05 D3 TDV6 HSE - Zambezi Silver
SA - 07 VW Golf TDI - White - Sold!
8th Mar 2007 2:20 pm
SN
Member Since: 03 Jan 2006
Location: Romiley
Posts: 13710
bkehoe wrote:
i'm sure you could bring it back if it didnt.
... even covered in mud and sh*t after a weekend on Salisbury Plain? Steve N | 21MY Defender | 08MY Discovery 3 (history) | 06MY Discovery 3 (ancient history)
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