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What is a good design for a Battery Monitor — Parallax Forums

What is a good design for a Battery Monitor

SailerManSailerMan Posts: 337
edited 2007-11-02 18:42 in General Discussion
Has anyone build one or can anyone recommend a good design of a battery Monitor (fuel Gauge) , Maybe point me to a schematic that they have used with good success.

I don't want to drain a lot of battery power monitoring the battery . [noparse]:)[/noparse]

Any help or suggested reading would be greatly appreciated.

Best Regards,
Eric

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-02 15:40
    What do you want the battery monitor to do? If you already have a Stamp doing something, there's a discussion on reading voltages with a Stamp using the RCTIME statement here: www.emesystems.com/BS2index.htm#interface near the bottom

    Depending on what you want to do and what type of battery you're using, maybe a simple micropower comparator will work along with some kind of micropower voltage reference. Maxim/Dallas has all sorts of very low power analog to digital converters, op amps, comparators, voltage references, etc. Take a look at their website.

    Post Edited (Mike Green) : 11/2/2007 3:45:03 PM GMT
  • SailerManSailerMan Posts: 337
    edited 2007-11-02 16:28
    Hey Mike,

    I'm building a 5V / 3V Buck Regulator PCB

    http://forums.parallax.com/forums/default.aspx?f=15&m=222582

    I though that I would integrate a battery Monitor into it.
    The Battery a 12 volt System probably Lead Acid.

    Eric

    ELECTRONICS ARE SO MUCH FUN!
  • Steve JoblinSteve Joblin Posts: 784
    edited 2007-11-02 17:21
    I'm on the same mission SailerMan!!!! I'm trying to find a simple circuit for monitoring battery power of a 12v Lead Acid. I found the following two circuits using a LM3914:

    http://www.uoguelph.ca/~antoon/circ/batmon12.htm
    http://www.reconnsworld.com/power_lm3914battmon.html

    I've also gotten some good feedback and ideas on Yahoo's Electronics Group Forum... http://groups.yahoo.com/group/Electronics_101/message/41279
  • SailerManSailerMan Posts: 337
    edited 2007-11-02 17:37
    Yeah I've see those too... It seems that every search brings those up. [noparse]:)[/noparse]

    I don't like the one at Reconnsworld as it suggests a separate 12 volt source to power the circuit.

    I'll have a look at your last link in Groups.

    Let me know what you come up with and I'll to the same.

    Regards,
    Eric

    Post Edited (SailerMan) : 11/2/2007 5:43:55 PM GMT
  • uxoriousuxorious Posts: 126
    edited 2007-11-02 18:42
    A simple LED gas gauge that I started a while back uses the BQ2010 from TI because the circuit is extremely simple. Maybe check that family of parts for one that will work for 12v and is a little cheaper. This one works for 3-5.6v.
    search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=296-2218-5-ND
    My gas gauge is a duplicate of the sample LED circuit in the datasheet, but uses an IO pin to "push the check button" and the LED pattern is displayed by LEDs. The next step is to get it to read the LED status as a 6 bit number.
    (IE: 50% battery=3 LEDs on= 000111). The BQ2010 can communicate but the datasheet is pretty intense for me to dig into now.

    I probably won't finish the gas gauge until I finish my wireless battery charger circuit. I'll be starting a thread on that as soon as I finish the prototype. This weekend hopefully.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ~~ dRu ~~
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