Eagle Eye Power Solutions

Did You Know? November 2020

Did you know, according to Siemens, NERC PRC-005 is the most violated NERC Reliability Standard?

It states that “Part of the difficulty is the detail to which a generator or transmission owner must understand and interpret the sometimes vague and confusing language of the standard into actionable and well documented maintenance plans.”

Furthermore, PRC-005 – for all covered battery types – requires that the float charge voltage be measured at the charger output. What about voltage drop? This is especially true with low-voltage DC where the voltage drop can be significant, especially if the cabling to the battery has been undersized. The charge voltage should be measured at the battery terminals instead.

Once again, on the subject of the proper charge voltage, most chargers and UPS systems come out of the factory with the float charge voltage set at a nominal setting – usually 2.25 volts-per-cell (vpc). Well, this is fine if the required float voltage of the connected battery is 2.25 vpc, but the chances are, especially with modern VRLA cells, that they may need a slightly higher float voltage. If the charger output voltage is not adjusted to suit, then the connected battery will be undercharged from day one.

Did you ever wonder how many AA batteries it would take to start a typical modern car?

This crazy writer has. A simple calculation would indicate, that since the approximately 250 amps required would need eight series connected AA’s in 25 parallel strings, so 200 AA batteries would do the job. But, if connection resistance and other factors are taken into consideration, then a more complex calculation would be necessary. A bit of research came up with an article in the December 2015 issue of Popular Mechanics Magazine that states. “. . . various reckonings suggest it might actually require anywhere from 1,200 to nearly 5,000 AA’s in total to crank up old Bessie. Given that, you’d be better off selling the batteries and using the money to buy a car that starts.” In my mind, rather than trying AA’s, why not just call AAA instead?

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