Laptop Power

bigmart

bigmart

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Hi All

I have aquired an old Compaq Laptop & some Maptech software to run the Charts on.

Connected this kit to my 150W Invertor & a power pack at home. Everything worked fine.

Went out on the boat at the weekend & the invertor tripped out within seconds of turning it on & wouldn't Charge the Laptop for the whole weekend.

I am assuming that I need a more powerful Invertor. What does the panel reccomend. Do I need a Pure Sine Wave Job or will the basic Square Wave job to the business?

I know you've got the answers. Fill me with your knowledge.

Martin
 
I'd go for a dedicated 12V laptop power supply (£30 from Maplins) rather than going through the Inverter/Mains PS route
 
I would agree with you except that this Laptop don't run off a separate power supply. The Mains (220V) plugs straight into the back of the Laptop.

Martin
 
No the batteries are of a lower voltage but I don't know what.

Its a Compaq Armada of about 5 or 6 years vintage, if that helps.

I have heard that its possible to wire straight to 12 Volts if you modify the battery. As I only have one battery & it is fully functioning, I am a litte reticent to destroy it.

Martin
 
Some inverters like the (boat) battery voltage to be above 12V. Is it possible the boat batteries were below this - if so it may be better to run the engine 'till the laptop batteries are charged at which point the load drops right down. I have used an inverter for years as I couldn't get a Dell 12V adaptor to run off boat batteries at around 12v.
 
I Did.

I even connected the power pack to the boat supply & the Laptop to the Power Pack. In fact I tried every combination of coonection I could think of.

I assume that it worked fine at home because I had fully charged the Battery in the laptop & fully booted the computer before connecting the Invertor.

I like a little reserve in my power arrangements than this so I would like to get an answer both reasonable in price & with some leeway in the margin of failure.

martin
 
Seems like you need a more powerful inverter. 150 watts @240v will output about 0.6amp. Assuming your 150watts is peak power then your mean power will be somwhat less ; maybe 0.4amp - so what's the power rating on the label on the laptop?
 
I've not got it with me at the moment.

I seem to remember 5 Amps being somewhere but that would mean a massive Invertor wouldn't it?

Martin
 
I know little about inverters, but if 150w is its output, then that is about 12 amps at 12v - even at a lower constant output you should get more than 5 amps.
 
5 amps seems a lot (this equates to just over 1200Watts so we're talking the current needed for an electric iron). I can't find power info re the Armada on the web, so do need to know either the power or current rating on the laptop.
 
Hi Mart
The inverter is buried somewhere deep in the electrical compartment and sorry, I can't remember the make other than a recollection it is French and is a 250Watt. I have it wired to a 13Amp socket by the chart table so that I just plug the laptop charger into it.
When I was configuring it I connected it up on the bench to see what the load was and how hot it would get. It drew 4.75A whilst the battery was charging and about .2A once charged. The heat wasn't that significant. It also gives me somewhere to charge the kids phones and the TV when we carried it on board. As nobody watched it we decided it was spare and took it home. The kids now prefer to come to the pub with us like at least one of yours (as seen at the Folly earlier this year!)
Cheers
 
Hi Piddy

I did wonder if it was you.

I took my other two to the Folly on Saturday night. I didn't see you though.

It sounds like a 250 Watt or slightly higher may do the job.

Martin
 
Your inverter at 150 watt seems large enough to charge the laptop.

Check out the input/output of the Compaq charger to check that out.

More probably:-

1. the system voltage dropped too low for the invertor to function. Try again with the engine on fast tickover, or with a charger going on shorepower.
2. the current blew or tripped the power outlet fuse/trip. Don't forget that thing is taking about 14 amps.

I only re-charge the batteries on my laptop with the invertor, because the sine wave produced is so square that it causes all sorts of firmware malfunctions, and only do that when system voltage is up to 14.4v (there's an Adverc and 3-way diode on the circuit).

I'll not recharge on shorepower for about a week to 10 days.
 
Bigmart. I could charge a 12v Toshiba with a 150wt inverter,
but not my daughters 19v widesceen Toshiba. I had to get a
600wt inverter off Ebay . Wasn't too expensive and I think
is square wave, but it has the power!! According to the back
of the 'puter it requires 6amps!!!
For boats 12 to 15 v laptops are easier.
However I now have an IBook that needs 24volts and runs
easily from a 12/24 DC converter. I am using the Apple
model but I'm sure a cheaper one would work as long as
you get the right connector. Some are sold with multiple
connectors. Visit Maplins.
 
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