Subject:
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Re: Battery Status
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Mon, 3 May 1999 22:40:59 GMT
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Original-From:
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Duncan Orthner <ORTHNER@IDIRECT.COMavoidspam>
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Viewed:
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870 times
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At 01:40 PM 5/3/99 -0700, Andre Philippi wrote:
> Hi,
>
> I would like to measure the battery capacity (how much longer can I keep the
> operating robot, running under the present battery), but I very newbie in
> regards to electonics... so here are my newbie questions... :)
>
> 1) Is voltage; information enough, to provide battery capacity (left) ?
This is usually how it's done. The voltage will drop predictably as the
battery discharges.
>
> 2) Could I use one of the analog ports on the Handy Board to measure battery
> voltage (and therefore calculate capacity left (assuming voltage is
> information enough for the calculation)) ?
Yes. You could use a voltage divider. You may have to play with the cutoff
point a bit, and be aware that nicads experience a rather sharp voltage drop.
Hope this helps, Duncan
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Message has 3 Replies:
 | | Re: Battery Status
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| [Duncan Orthner] spake unto the ether: (...) But isn't the supply voltage also the reference for the D/A converter? If the reference drifts, the signal through the divider leg will also drift? I remember trying something like this with a variety of (...) (25 years ago, 4-May-99, to lugnet.robotics.handyboard)
| | | Re: Battery Status
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| (...) However, I'd be concerned about this method in the long run. I'm thinking that the discharge rates of some batteries change over time (talking rechargables here), and that may screw you eventually. Of course, I haven't the faintest idea for a (...) (25 years ago, 4-May-99, to lugnet.robotics.handyboard)
| | | Re: Battery Status
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| (...) battery (...) drop. (...) Umm, yes. But only if the battery is 5volts. Presumably, the voltage regulator on the HB is being supplied with well over ~6.5 volts (usually a 9.6v battery). Thus the output of your divider could be read via an (...) (25 years ago, 4-May-99, to lugnet.robotics.handyboard)
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Message is in Reply To:
| | Battery Status
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| Hi, I would like to measure the battery capacity (how much longer can I keep the operating robot, running under the present battery), but I very newbie in regards to electonics... so here are my newbie questions... :) 1) Is voltage; information (...) (25 years ago, 3-May-99, to lugnet.robotics.handyboard)
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