Hi All.
Please look at the example 'C' rating of a battery below.

In simple English, does the 2 minutes indicate the fastest amount of time a battery can be discharged without killing itself or catching fire?

Thx 4 the replies!

 

The "2.3A" should be 2.3Ah (amp hours since it was simply converted from 2300milliamp hours when divided by 1000.

otherwise, yes, discharging at 30C means in 2minutes in this example. A C-rating of C1 is 60-minutes and a C-rating of C30 is 2-minutes.

 

In theory, C = 2300mAh means a discharge current of 2.3A in 1 hour.

In practice, this may not be the case depending on many factors. Your biggest limitation will be battery chemistry and internal resistance of the battery.

#1 - state the battery chemistry

Lithium-ion battery will likely catch on fire at 30C.

 

the C rating is the amout of capaicty the battery has, in this case its 2.3Ah so you can charge or discharge it at 2.3A for 1 hour or multiples therof,

IE. 1.15A for 2Hours/ 0.575A for 4hours/ ).287A for 8 hours.

Taking more than the C rating will harm the battery faster.

 

does the 2 minutes indicate the fastest amount of time a battery can be discharged without killing itself or catching fire?

Not necessarily.
69A for 2 minutes is 2.3Ah, so that's the theoretical time where the battery is fully discharged.
In practice, it will be discharged in less than that time.
And fully discharging a lead-acid battery usually damages it, unless it's a deep-cycle type battery.

 

As usual things are more complicated if you want to calculate accurate dynamic run-times on some types (not lithium-ion batteries ) of batteries with simple coulomb counting.

https://en.wikipedia.org/wiki/Peukert's_law
https://www.batterystuff.com/kb/tools/peukert-s-law-a-nerds-attempt-to-explain-battery-capacity.html

 

the battery was given a 30C rating because it has low internal resistance and can be discharged at that rate without catching fire (in theory). The 30C rating doesn't mean it can be done without impacting the life of the battery, it will surely last fewer charges if discharged quickly instead of slowly.
If you need to do it (want to do it) for a drone competition or RC racing competition - absolutely, that's the way to minimize mass and maximize power to win a race. The people who win don't think about maximizing the number of charge cycles.

 

Not necessarily.
69A for 2 minutes is 2.3Ah, so that's the theoretical time where the battery is fully discharged.
In practice, it will be discharged in less than that time.
And fully discharging a lead-acid battery usually damages it, unless it's a deep-cycle type battery.

I'm pretty sure these specs are for LiPo, not lead-acid.

 

The only 30C batteries I have come across are LiI ion and designed for drones.

Bob

 

30C is only a theoretical PEAK Current "capability",
and is not "guaranteed" performance,
and, the Battery can not be expected to provide this level of Current continuously until it is "dead".
Abuse at this level will most certainly, significantly shorten the Battery-Life-Expectancy.

A reasonable compromise is to maybe expect HALF of this absurdly inflated rating.
More Peak-Current is what everybody wants, so there's no limit to the advertising hype,
BS Alarms should be going off everywhere.
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A reasonable compromise is to maybe expect HALF of this absurdly inflated rating.

Unless you are in racing competitions and expect to replace the batteries after each round because doubling battery weight would significantly slow the drone or car.

 

It's like a horsepower rating of a drag racing motor. You pays your money, you takes your chances.

 

It's like a horsepower rating of a drag racing motor. You pays your money, you takes your chances.

And those guys, running engines about 8k to 10k RPM for 4.5 seconds expect less than 1000 revolutions between motor rebuilds.