-1
\$\begingroup\$

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.

\$\endgroup\$
4
  • 1
    \$\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
1
\$\begingroup\$

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
\$\endgroup\$
2
  • \$\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

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.