In addition to this, if you have an oscilloscope available to you, you can measure this with the scope and see if this is what's happening. It's probably a worthwhile experiment for you i fyou have the tools availble to you.

Embedded software guys and an oscope, don't leave home without it. :)

Let us know what you find!
Rick


On Thu, Aug 20, 2009 at 2:18 AM, Dave Hylands <dhylands@gmail.com> wrote:
Hi Dustin,

On Wed, Aug 19, 2009 at 6:21 PM, Dustin Webb<dustinjwebb@yahoo.com> wrote:
> Thanks again for the info Dave.
>
>> You'd actually be better off to pick batteries closer to 5V.
>> Everything above 5V is wasted as heat in the voltage regulators. A
>> 5-cell NiCad or NiMH will run from around 7V fully charged down to
>> about 5V when discharged.
>
> It's interesting that you say this because this is what I thought based on
> the documentation. However I find that if I don't have close to 9V then my
> WiFi doesn't work. In fact i was originally using a 6V battery but had to
> change batteries because of this problem. Not sure what I am doing wrong.

It may depend on the battery. Cheap alkalines, for example, have a
high internal resistance and are unable to deliver big inrushes of
current like the NiCAD and NiMH batteries can.

And the voltage of a battery will droop when you take a big load from
it (Wifi represents a pretty significant load and it's quite bursty).
So it's possible that the 6v battery (the 6v is only a nominal
voltage) may be sagging enough to cause problems.

When you look at batteries they have a couple of different ratings.
One is mAh (milliamp hours) which represents how long it should last
delivering a particular current. The other is N-C where N is a number.

Here's some good background: <http://batteryuniversity.com/print-partone-16.htm>

So having a 6v battery should be fine, provided it has a low internal
reistance (like NiMH or NiCAD) and that you've got enough oomph. So
you'll want a battery with at least 1000 mAh.

--
Dave Hylands
Shuswap, BC, Canada
http://www.DaveHylands.com/

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