18650 battery question

[dr g]

A little [very] technical reading on the topic.

Understanding Boost Power Stages in Switchmode Power Supplies

The people at ProVape are correct...Our batteries can be subject to VERY high amp loads due to current pulses of a boost converter. How much current depends on too many variables to even speculate, but it certainly can be as much as double the average current.

BUT......I take it with a grain of salt. Here's why...

A battery's max discharge rating is set with the goal of limiting heat production. batteries have internal resistance, and when you have resistance and electrical current, you get heat. Battery gets to hot...bad things happen. So say you have a battery rated for 6A, and you are pulling 4A average current from the battery. This means that you could have 8A peak current being pulled from the battery. This peak, however, is only ~100 microseconds in duration (0.0001 seconds) and repeats itself 800 times per second.

Is that enough time to generate enough heat to damage the battery? I would argue that it is not. My reasoning behind that argument is the [probably] thousands of Provari Mini's that have bee sold that do exactly as I described above. The AW 18350 is rated for 6A continuous discharge and by ProVape's own proclamation for high drain batteries, their device is pulling 9+ amps from a 6A battery.

Exactly, this is not the same thing as even the battery's "pulse" rating. If it were seeing a true effective load of 8+ amps it would have a ton of power to dissipate (heat) and be terribly inefficient.

And this is what I mean when I always say putting a regulator on a battery is putting a very low subohm load on it. It won't behave like a mech subohm load due to the duty cycle. In the end the effective draw from the battery is going to be very close to the non-switched equivalent.

If it isn't, either something's wrong with the regulator or it's not an appropriate regulator for the application.

One last thing...if it is powered by a battery, and allows you to change the voltage either up or down...it is a DC-DC Converter

Glad to know I'm not going crazy here.