fried inverter with chips and sauce

[seafox]

As Wheels knows, my inverter decided to cook itself last week.
All I use it for is to power my laptop. Seems pretty inefficient. 12V convert to 240v with inverter and then connect laptop power adaptor to convert to 19v.

I saw these advertised in a Repco brochure. They convert the 12v to the 19v and are designed for laptops.

I know bugger all about this sort of thing but, would this use less of my boat battery to power my laptop? Would it be better than the inverter?

Projecta click on this to see it.

[btrayfors]

Seafox,

You gotta be careful about small auto or airplane power sources for laptops, because they often are not suited for small sailboats. This is because they are meant to work at voltages normally present when a car engine is running, i.e., 13 to 14.5 volts or so. Often, below about 12.8 volts, they don't put out enough voltage to charge your laptop battery.

Take, for example, the typical DC power adapter for IBM laptops. These work fine at higher input voltages, but on a sailboat where battery voltages are often below 12.6, they won't charge your battery. They will run the internal laptop battery down. I have two such adapters from IBM, and they both exhibit the same behavior.

Solution: an adapter which works well at lower input voltages. Best I've found is from Lind Electronics (they make robust adapters for IBM and many others), and they have models which will work with input voltages as low as 10V or so. I've used one happily for several years now. Auto Power Adapters, Auto Air Adapters and Power Packs for Laptop and Notebook Computers.

Bill

[Pblais]

know bugger all about this sort of thing but, would this use less of my boat battery to power my laptop? Would it be better than the inverter?

The 12 volt PC auto adapter will use the least power. The only issue I have ever found was with an HP charger that had two modes and handled both AC and DC input (a bit spendy but the only one I could get with the right PC connector). It had a mode that would recharge the battery and at the higher rate it blew the in-line fuse on the DC line. I don't let the amps go too high on anything if I have a choice with so I just don't use the high setting except in AC mode. Other laptops I have used have all had just one setting and were just fine. battery.com and batteryplus.com both handle generic adapters. Just make sure you get the one for your laptop. There are a lot of different connectors. about $70 usually does it. The HP one was more.

Using DC to make AC so you can make DC wastes at least 20% if not a lot more.

[seafox]

Thanks,
I noticed that the input range was around 12.8V plus. You are right, the boat gets down well below that.

I have got an old battery that I could use just to run and not charge and then switch to the good battery when the motor is going. Would that work?

Also would the 6A output adaptor work on my 6.3A input pc?

[NoTies]

I use a 12VDC adapter for my laptop even in the marina. I bought one of the adjustable output voltage ones and installed a voltmeter in the output line to monitor it. Whenever my battery voltage drops off I click it up a notch. You need to remember to drop it back before starting the engine or plugging into shore power charger though.

[seafox]

bit tecky for me

[Alan Wheeler]

Yeah Darryl has that 'Paula bring me another beer" approach. :-)