lipo LIES: huh?
DataUsed packs Huh?Backend? Help me

What the heck is a C rating?

Hi Ashburn ! Damn good question, buddy.

Some batteries can deliver more powerful currents continuously than others without exploding, without wasting as much of that current on generating heat versus delivering more power to the motor and without needing to be replaced after only a few flights before its capacity and power diminishes.

This trait, the unit of measurement for it, is referred to as a battery's C rating. That's the gist but I'll offer links to explanations written by much smarter people -- I'm just a rookie.

(this is a rough draft, still revising, maybe you should instead watch this video..)

Mathematically, a battery's C rating is its amp hours multiplied by the C rating. That we all agree on. For example, a 2800mAh 100C battery ought to yield this safe continuous current at 280 amps. While someone flying a VisionAire or an Extra 300Q, for example, may only need a 50A current, the overkill high C rating is appealing because it implies the battery will deliver much closer to the same voltage, thereby not spinning the motor much slower, under heavier full-throttle loads. This is called voltage sag. A big deal for 3D flyers who will pay double for a battery promising double the C rating of another.

Purportedly, here's a 2800mAh 3S 30C weighing 200g from ValueHobby for $23. And here, purportedly, is a 2800mAh 3S 100C weighing 188g from MaxAmps for $70. The MaxAmps battery promises the same capacity, less weight, safe continuous delivery of over 3x the current and for 3x the price. Draw your own conclusion...

There is no set of standards nor a regulatory body to force or lightly pressure MaxAmps (or ValueHobby) not to grossly exaggerate the C rating in order to sell more batteries at higher prices. And so the RC community has learned that these claimed C ratings are absurd and next to meaningless, some vendors and brands far more than others.

So to offer those looking to buy batteries who care about C ratings batteries' actual C ratings, as diligently as I am able I have been testing batteries of various brands and claims in consistent and controlled manners, for example making sure the packs' temperature when taking readings is 22C, cycling multiple times and so forth as I outline here.

Doug Simmons