stand alone BTS ?

sunbunnysunbunny Solar Expert Posts: 59 ✭✭✭✭
I can't find a stand alone battery temp. sensor/readout.
Am I going to have to buy a meat thermometer and cobble something up ?

Thinking about using 5 of them to monitor my less-than-ideal battery setup so cheap is good.

Comments

  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: stand alone BTS ?

    Here is a thread where it was discussed. My batteries wer at 87.7 this morning, what am I going to do about it, nothing but keep on charging and using them, thats life. They have only been bulked for 3 days there is nothing a BTS can do.

    http://forum.solar-electric.com/showthread.php?19967-Battery-Thermometer
  • sunbunnysunbunny Solar Expert Posts: 59 ✭✭✭✭
    Re: stand alone BTS ?

    Guess I should have said that they are AGMs so have to do a stick on sensor.

    I have an IR point + shoot thermometer. Will taking the temperature of the top of the battery be acurate enough ? 'Cause they will be in a box of some kind.
  • BB.BB. Super Moderators, Administrators Posts: 29,511 admin
    Re: stand alone BTS ?

    Some people get a remote reading electronic thermometer (just a standard weather type) and get a block of Styrofoam.

    Carve out a place in the block for the sensor, and place it on the side of one of the inner batteries. I till give you an accurate enough reading for most needs (batteries do not change temperature very quickly, and the foam block will keep airflow around the batteries from affecting the readings).

    Readings within ~5F (2.5C) should be "good enough". Readings 10C (18F) or more off, very significant errors.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sunbunnysunbunny Solar Expert Posts: 59 ✭✭✭✭
    Re: stand alone BTS ?

    Thanks, Bill.

    Do you mean battery temp. different from ambient or from each other ?
    I want to monitor each pair because temp. differences might give me a warning about poor charging.
  • BB.BB. Super Moderators, Administrators Posts: 29,511 admin
    Re: stand alone BTS ?

    Both from the "scientifically" exact temperature (i.e., 72.5F measured vs 75.0F exactly)--And from each other (i.e., batteries within 5F--perfectly OK; batteries and posts that are 18F or farther apart, probably something wrong).

    Batteries in the same string that are 10C hotter (18F), are going to age 2x as fast at that hotter temperature (with ~77F/25C as "STC" standard test conditions). As well as showing that "something" is different (high resistance battery, shorted cell, high resistance at terminal/cable connection, etc.). It could also be batteries in front get good air flow, and batteries crammed in a corner get poor air circulation (again, if the temperature difference is "great", then bad things are likely to happen).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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