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I am a grade 11 student performing a experiment on relating how external temperature affects the performance of a battery, so its voltage and current change. I've done so much research and cant find a formula that relates temperature to any parameters of a battery. The experiment plan is to get a battery and discharge it at different temperatures but the problem is that I need to have a theoretical formula that supports the results. Could any of you please help find some formulas that I could use. Thank You.

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    \$\begingroup\$ What battery? does it have a model #? \$\endgroup\$ – Voltage Spike♦ Feb 11 at 0:15
  • \$\begingroup\$ Lithium Ion Polymer Battery - 3.7v 100mAh \$\endgroup\$ – Kirill Delyukin Feb 11 at 0:17
  • \$\begingroup\$ I need to have a theoretical formula that supports the results .... what if the results of a carefully conducted experiment do not match the formula? \$\endgroup\$ – jsotola Feb 11 at 2:53
  • \$\begingroup\$ Nothing really, It can be blamed on sources of error and other factors in the unideal conditions. I just need a way to calculate and determine the trend. \$\endgroup\$ – Kirill Delyukin Feb 11 at 3:38
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LiPo batteries have a nonlinear behaviour with temperature and varies widely with quality of construction, although there are some generalizations.

Assumptions

  • Battery model specifications take precedence over generic expectations
  • test with controlled constant current sink vs voltage must not stay under/over voltage for any significant time.
  • if specs define capacity and charge cycle life, these will affect temperature results
  • several batteries must be tested to determine standard deviation of the experiment
  • example specs
    • enter image description here
  • search "google images" for 100mA LiPo temperature performance graphs
  • search battery university site for experience
  • search "Google Scholar, Microsoft Academic" Research-gate enter image description here
  • define test specs, test methods ( dry ice, thermometer, test point, self-heating), measurement intervals, estimate an acceptance criteria, choose CC sink design, automate test
  • have fun
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  • \$\begingroup\$ Thanks I am starting to understand, although is there any specific equation I can use to determine the amount of power it could deliver at -10 C rather than at 10 C \$\endgroup\$ – Kirill Delyukin Feb 11 at 3:42
  • \$\begingroup\$ Looking at the graph it drops from 90% to 65%. Can you use a spreadsheet with curve fit? \$\endgroup\$ – Tony Stewart EE75 Feb 11 at 5:09

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