16VDC 2.5A computer adapter

[Finntec]

I have an IBM Think pad laptop with an AC cord that states 16V 4.5A. They sell a 16VDC 2.5A IBM computer adapter for the car that I am considering getting for my TD, but:
Will this work off a single Group 24 80AH battery?

Am I correct that in an automobile, the alternator would be putting out enough voltage to run this, but isn't the voltage is regulated at the 12V accessory output?

We just want to watch movies and listen to music on rainy days/nights. Any suggestions?

[Steve F]

I have an IBM Think pad laptop with an AC cord that states 16V 4.5A. They sell a 16VDC 2.5A IBM computer adapter for the car that I am considering getting for my TD, but:
Will this work off a single Group 24 80AH battery?

Am I correct that in an automobile, the alternator would be putting out enough voltage to run this, but isn't the voltage is regulated at the 12V accessory output?

We just want to watch movies and listen to music on rainy days/nights. Any suggestions?

The adapter is stepping the voltage up to 16v, you may find that the 2.5A output is not enough though, I don't really know enough about laptop requirements to say if it would work or not on 2.5A. The 80AH battery will be fine.

Cheers
Steve

[eamarquardt]

I have a couple of laptops (sony and toshiba). The Sony's battery went kaput and they are expensive. Looking for a more cost effective way to keep it going I bought a car power adapter (like the one you have) and for about $20 bucks at the local battery store got a sealed wet acid battery used in alarm systems and other stuff. It has about 5 amp hours of capacity. I use it rather than spending the big bucks for a new sony battery and it works fine. I also keep the battery in parallel when I use the laptop as a gps when I go garage saleing every Saturday morning. That way the blip in the voltage doesn't cause the computer to reboot when I start the engine.

Hope this helps.

Cheers,

Gus

[Dale M.]

Using wrong adapters or kludging something up that is under/over powering laptop may end you costing you more than what you save from buying proper adapter.... Like total failure of laptop!...

If laptop wants 16 volts to operate, I would stay within that parameter.... Usually auto adapters are a step-up power supply to output that lap top requires....

Other way you may consider is getting low cost inverter that changes 12 volts to 120v AC and just plug in your AC cord/power supply for laptop into that...

Dale

[eamarquardt]

I agree that underpowering things can cause damage, particularly a/c motors and long extension cords. The adapters I use do step the voltage up from 12 volts to the voltage required by the computer. My experience with the auto adapter for computers is if the voltage gets too low the computer merely shuts down (inconvienent but I haven't seen any long term consequences).

I'd be interested if anyone has had a different experience.

Cheers,

Gus

[brian_bp]

No, the voltage at a car's accessory socket is not normally (and probably not in any case) regulated; it's just wired to the battery, typically though a relay (just on/off, not a regulator).

The adapter for a laptop needing 16V will have a DC-to-DC converter to get to that voltage, and regulate the output... it will allow for typical battery voltage variation.

The only problem with a supply which has inadequate capacity is that if more capacity is needed, then its voltage will likely drop (or it will cut out entirely due to overload). That sounds less than ideal to me, but remember there is still a battery in the laptop (assuming you leave it in), so all that would likely happen is that the battery stops charging and the laptop runs on the battery for a while. The laptop's internal power supply, battery, and battery charging circuits are effectively a UPS (uninterruptible power supply), so a potentially inadequate auto adapter doesn't seem like a big concern to me.

2.5A at 16V isn't very much power for a laptop, but if you are not running the optical drive (CD or DVD), working the CPU hard, exercising the hard drive, and driving an external display - all at the same time - you may never need the full output of a typical power adapter.

[Finntec]

Thanks for your help everyone. I'll give it a try in a couple weeks when the weather gets nicer.