[ltp] self-made external battery for laptops project

[Bart-Jan Vrielink]

On Sat, 2002-04-20 at 04:47, peter nol wrote:
> Wow Richard you really know your stuff!
> Looks like the riddle is almost solved.
> You wouldn't have any knowledge about the four power contacts for the battery 
> would you?

Just forget about those contacts... use the AC plug, much easier and
much safer.
 
> Now to think of a way to make the whole construction economical and match up 
> actuall parts. 

I think you end up with one of the following options to get a DC voltage
of 16V out of a set of batteries:
- a 12V battery and a voltageconverter from 12v to 15-16v (very
expensive)
- 2 12v batteries (or one 24v battery) and your average voltage
regulator (not expensive, but you'll need two batteries)
- one or more batteries that provide (almost) the right voltage, like
for example two 7.2 racing packs (for rc cars) in parallel, giving a
14.4 V output at 2Ah for under 30$.
- a dc-ac converter between a regular 12V battery and your thinkpad AC
adapter. I've seen one for $40 dollar that has a cigarette plug as input
and provides 80W continous output at 230V (I'm in europe, but I'm sure
devices like this are available in the US as well, maybe for even better
prices).

Remember that for your project you will also need some kind of battery
charger.
 
> I thought acid-lead batteries didn't have spikes as such though.

Dunno, but if you also want to charge the batteries while using the
laptop ?? Are you sure that the battery charger does not have spikes.

-- 
Tot ziens,

Bart-Jan


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