Re: LAPTOP BATTERY POWER FROM 75-150Ah ?

On Mar 20, 5:34 pm, datakoll <datak...@xxxxxxxxx> wrote:
I'm missing here. I'm concerned the 75aH and 2 75aH (150 aH) deep
cycle batteries offering way too much dc power for the Dell 1705
laptop at est. 5 amps at 10.38 volts.
Thus, a device is necessary between the battery bank and the laptop.
The 10.38 voltage is from the standard lithium laptop battery. So a
75aH deep charge should have enough voltage to supply the laptop.
My approach was a dc to dc connection saved power over an inverter.
Using an inverter btween two dc devices is not logical.
a transformer ?

The auto adapter suggested IS a DC/DC converter. Targus makes (OK, has
made for them) a few models that take both AC and DC inputs, then
supply power to the notebook using a tip that somehow instructs the DC/
DC to provide the proper voltage. My guess is the tips have a resistor
to tell the power supply what voltage is required.

As a person that likes to run ham gear in the field, I'd be more
inclined to roll my own LDO. These DC/DC make a hell of a lot of RF
hash.

I will tell you that I had one Targus fail in the field. It failed
quite dramatically, with the tip melting. It got so hot that the
notebook power input hasn't been the same since. Unfortunately, there
are not a lot of alternatives out there. Kengiston is another company
that has these universal supplies built for them. I wish Belkin would
get in the business. Not that Belkin makes (OK, has made for them)
gear superior to anyone else, but at least Belkin has a lifetime
warranty. I've had Belkin crap replaced no questions asked. All you
pay is the shipping to the factory.

In theory, you can use an inverter, then the AC/Dc that came with the
notebook. This makes even more RF hash. I friend the supply that came
with my Fujitsu using an inverter, and I am gun shy about running any
electronics on a modified square wave. However, an offline swticher,
which just rectified the line voltage as the first step, should not
care that the input is a crappy modified sine wave. Possibly the peak
current in the diodes would be higher, but you would think the
designer of the offline switcher would consider the possibility of a
square wave being the AC source.

.

Relevant Pages

  • Re: battery charger topology
    ... substantial powers used to charge a 300Ah 24V lead acid battery bank ... normally have to build into the design. ... sets the voltage you must boost to. ... 100KHz may be a bit fast for the power level. ...
    (sci.electronics.design)
  • Re: Call to ban petrol cars by 2040
    ... The extra power supply capacity is ... Laptop supplier the draw it places is 45w normally with a peak of 65w two ... With no battery in place, so the charger is just powering the laptop, the ... The no-load output voltage of the charger is about 20V - sorry, ...
    (uk.transport)
  • Re: Illogical emotional attachment?
    ... >>> They all promised incredible battery life and they all failed to ... If I can get an hour out of my Sahara laptop with Centrino ... > after about 15 minutes the power level had dipped down to around 65%. ... flip a hardware switch to immediately toggle between the two video cards to ...
    (rec.photo.equipment.35mm)
  • Re: HP Pavilion Laptop Owners with Bad Power Jacks....
    ... jack dilemma. ... I purchased a HP laptop to keep all HP software off my other systems. ... power jack and are not HP laptops. ... Like many others I assumed the battery had failed ...
    (comp.sys.hp.hardware)
  • Re: Another Battery Charging Question
    ... has some sort of compensation for lower voltage and will still work. ... I now use this with a generator or shore power. ... other two ways to charge from the truck: booster cables battery to battery ... You'll have to try it to see if your 400 watt inverter really will ...
    (rec.outdoors.rv-travel)