A battery’s “capacity” is listed in “milliamp-hours”, which is a measurement of dialectic flux, not energy. This means a 7.4v 4000 mAh battery and a 14.8v 4000 mAh battery have the same “capacity”, even though the latter can store twice as much energy as the former! For racers who generally stick to one voltage, this isn’t a big deal, but for bashers who will experiment with 2s, 3s, maybe even 6s packs, a capacity measured in watt-hours, an actual unit of energy, will be more useful for comparing packs.
“C” ratings are ridiculous as well. You know “C” is a measurement of? Frequency. 1C ≈ 0.277 Hz. The number you actually want out of a battery is its discharge current, which should be measured in amps. Sure, you can calculate this by multiplying the C rating by the “capacity” in amp-hours, but why not just cut out the middleman! And as for the charging current, normally stated at “1C”, why not let the manufacturer suggest a current instead? They probably know best, since they made the damn thing.
Before: “7.4v 4200 mAh 65C”. After: “7.4v 31Wh 270A”
I’m not even sure why we bother with discharge rate anyway. What we really want to know is internal resistance…
RCBS is a column where I rant about things in R/C that don’t make sense, but everyone accepts them anyway.
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