Laptops

[Guest]

I have a Toshiba Satelite laptop which I would like to use on board my boat.
Does anyone know whether I should use my existing invertor or should I purchase a 12v. supply cable to use through a cigar lighter switch

 

[Guest]

I'd keep the inverter and also wire the laptop to a 12V supply, both suitably fused/switched. Then if the inverter packs in you can still run it from boat's batteries - might be more efficient in any case...

 

[Guest]

i use a 12 volt cigarette charger on mine & have had no problems

 

[Guest]

Does your inverter put out enough power? Mine is only good for recharging the battery.

 

[Guest]

12V is fine, but may not charge the battery .... I use both methods .... no problem.
My invertor is a small 100W, max 150W job and that is fine .... but mainly thats for Video recharging / stereo use.
Most Notebooks, (Laptops - actually went the way of the dinosaur .... ) will run from 12V ..... as most are supplied from mains boxes that reduce to 15V or 20V .....

 

[Guest]

Can you confirm/correct implication. I have slightly older (!!!) Toshiba which runs on 18v - that is mains transformer outputs 18v / 1.1amps. Are you saying this should run acceptably plugged into a cig lighter socket on a 12v system? Many thanks.

 

[Guest]

Re: Laptop power supply

don't quote me on this as I've not looked too closely at a Tosh lately, but most PC circuits (portable included) require +5v +12v and -12v to run it. This will be produced internally via DC to DC convertors that run from the 18v.

Probably, these will run from 12v, but if this voltage drops you might find that the dc to dc's will become unstable and the PC will crash. Additionally, you might find that supply filtering is done in the remote power supply. Thus you may not have as much protection against noise and spikes as you would like.

In this case where the laptop is normally supplied with 18v from the remote supply, I would suggest that you use an invertor and the manufacturers power supply.

kev
www.yachtbits.co.uk

 

[colinroybarrett]

Toshiba power supplies

All of the Toshiba “Satellite Pro” series (that I’ve seen) have a 15v DC supply from the mains. Over the range they mostly seem to vary only in current output, not voltage. The supplies main purpose is to recharge the internal battery with the added benefit that they power the box if it is in use.

The internal charger circuit is quite complex, consuming varying current, dependant on time and state of internal battery; there are rest and heavy charge periods, with a final “float charge” in pulses. It is thus quite difficult to define how much power the thing consumes.

Since our well-regulated boat or car engine alternator should provide no more than 14.4volts, no harm can be done. I use a direct cable (cigar lighter socket) to the DC in of the LapTop. If the battery volts are way down, the charge light on the LapTop flashes orange, presumably not charging. Otherwise it will run OK, going to fully charged, if the engine is running and the boat batteries are well charged. So far, I’ve not had any problems using this method to power the PC whilst under way.

Cheers, CRB.

 

[vyv_cox]

Laptop power supply spikes

I have read that a boat's 12V supply can be too unstable to drive a laptop without frequent software crashes. Using an inverter is supposed to overcome this. One problem I can forsee is that the fridge cuts in and out every few minutes, perhaps 5 Amps. Can laptops survive this level of variation in supply?

 

[kdf]

I have a Toshiba Portege 7200 on my boat with a 12v adapter from a company called Teleadapt (www.teleadapt.com). It plugs into the cigarette lighter outlet and gives the laptop up to 15 volts when running. It's pretty good and allows me to charge the laptop on the boat. It's not cheap (£90) but I'm happy with it and so far I've had no problems with other equipment causing spikes on the supply

 

[colinroybarrett]

Re: Laptop power supply spikes

It may be only the Toshiba, which as I said, seems to use power only to re-charge, not running directly from the supply itself. Admittedly (since I’ve no real use for the LapTop onboard) I haven’t made a long-term study of the effects of the fridge etc. but so far so good…..

The inverters, 12-15volts are almost certainly the best way to go. Given the Lap-Top costing the best part of £1,500 then £40-60 for an inverter is a small price to pay for peace of mind, even if it doesn’t seem (in the Toshiba’s case) strictly necessary?

Cheers, CRB.

 

[robp]

Re: Laptop power supply spikes

I actually bought a 12VDC to 19VDC supply adaptor for my notebook the other day, on the basis that I can use it in the car too. Not cheap but probably more efficient than my invertor.