Tag Archives: battery

Battery Freezing Math

I live in a cold climate -- so cold that under certain circumstances we can freeze our lead-acid batteries (Figure 1). A customer who lives in my region called recently and was wondering if I thought any of his batteries would have frozen over the winter. A number of his Internet service subscribers have vacation homes that are unoccupied over the winter. All of these vacation home owners turn off their AC power for the winter. Since all of our Optical Network Terminals (ONT) are connected to Uninterruptible Power Sources (UPS), they will begin operating off of their battery when the AC power goes away. If the home owner does not disconnect the battery, the ONT will run discharge the battery. This is important because a discharged battery will freeze -- a charged battery will not freeze. A battery that has been frozen is very likely a dead battery. Continue reading

 
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Thermal Runaway Model of Lead-Acid Battery (Part 2)

Derivation of the Output Power Equation The output power equation (Equation 3) is really a restatement of Newton's law of cooling. Equation 3 states the battery's steady-state power dissipation is a linear function of the battery's temperature and the ambient … Continue reading

 
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