The number of batteries is an interesting number: 6831. That's 9 * 11 * 23, an unusual number of large prime factors. One reference suggests that it's 11 group

The number of batteries is an interesting number: 6831. That's 9 * 11 * 23, an unusual number of large prime factors. One reference suggests that it's 11 groups of 9 series strings of 23 parallel cells. Somebody there likes prime numbers.