I think I've found a problem with the Vamo, and I'm curious if anyone else has experienced this.
Now, this issue only occurs under specific conditions: With stacked 18350s in variable power mode with a low res carto.
Here's what I think is happening: When in variable power mode, and you change cartos/atties/clearos with a different resistance, the Vamo seems to take about 0.5 to 0.75s to read the resistance of the device and set the voltage accordingly once it's gotten its reading. While it is reading the resistance it will use the last set voltage until it gets its reading and adjusts accordingly.
Similarly, when you change batteries, upon firing the carto for the first time it will spend half to three quarters of a second reading the resistance before setting the voltage properly. However, because it does not remember any settings (other than whether you were in variable power or voltage mode, and the AVG/RMS mode) it has no last set voltage it can call on to use while it's getting a reading, so it seems to fire through the unregulated voltage of the battery until it has its reading, where it will then regulate the voltage to meet your set wattage.
This is a problem.
Let's take a less serious scenario. You're using an 18650 (or a single 18350 in mini mode). You're set to 10W with a 3ohm carto. That's 5.5V. No problem. Now you switch to a low res carto, 2ohms. For 0.5-0.75s, it's going to be testing that atomizer at 5.5V -- that's 15W. This is not necessarily catastrophic, but that's pretty damn hot and may scorch the juice while it's testing, so you may get a few puffs of slightly off-tasting juice until you vape past it.
Now, if you're just changing to a fresh 18650 this is not a problem, as that first <1s test will only be pushing 4.2V unregulated at most -- 8.8W with a 2ohm carto, well inside acceptable levels.
Now use stacked 18350s. Things get more serious.
Fresh stacked 18350s inserted. 2ohm carto. Hit fire. For that first 0.5-0.75s on that first hit, the device is now blasting 35 watts through that carto. (8.4v unregulated through a 2ohm carto) Even for such a brief time, this is enough to damage or even pop coils. I've already damaged two SmokTech 2.2ohm single coil stubbies because of this. They didn't pop, but the first one saw its resistance drop to 1ohm, and the second to 1.5ohms (now 1.3ohms as I continue to use it -- might as well get what life I can out of it.)
Even with a 3ohm carto that's still a brief blast at 23.5W. Possibly not enough to damage but not far enough away from that possibility for my liking.
Has anyone else run across this issue? Because this thing should be using the lowest possible voltage when doing its resistance check, not allowing unregulated current through until it gets its bearings. But I wanna know if it's my device or if others have run across this.
Now, this issue only occurs under specific conditions: With stacked 18350s in variable power mode with a low res carto.
Here's what I think is happening: When in variable power mode, and you change cartos/atties/clearos with a different resistance, the Vamo seems to take about 0.5 to 0.75s to read the resistance of the device and set the voltage accordingly once it's gotten its reading. While it is reading the resistance it will use the last set voltage until it gets its reading and adjusts accordingly.
Similarly, when you change batteries, upon firing the carto for the first time it will spend half to three quarters of a second reading the resistance before setting the voltage properly. However, because it does not remember any settings (other than whether you were in variable power or voltage mode, and the AVG/RMS mode) it has no last set voltage it can call on to use while it's getting a reading, so it seems to fire through the unregulated voltage of the battery until it has its reading, where it will then regulate the voltage to meet your set wattage.
This is a problem.
Let's take a less serious scenario. You're using an 18650 (or a single 18350 in mini mode). You're set to 10W with a 3ohm carto. That's 5.5V. No problem. Now you switch to a low res carto, 2ohms. For 0.5-0.75s, it's going to be testing that atomizer at 5.5V -- that's 15W. This is not necessarily catastrophic, but that's pretty damn hot and may scorch the juice while it's testing, so you may get a few puffs of slightly off-tasting juice until you vape past it.
Now, if you're just changing to a fresh 18650 this is not a problem, as that first <1s test will only be pushing 4.2V unregulated at most -- 8.8W with a 2ohm carto, well inside acceptable levels.
Now use stacked 18350s. Things get more serious.
Fresh stacked 18350s inserted. 2ohm carto. Hit fire. For that first 0.5-0.75s on that first hit, the device is now blasting 35 watts through that carto. (8.4v unregulated through a 2ohm carto) Even for such a brief time, this is enough to damage or even pop coils. I've already damaged two SmokTech 2.2ohm single coil stubbies because of this. They didn't pop, but the first one saw its resistance drop to 1ohm, and the second to 1.5ohms (now 1.3ohms as I continue to use it -- might as well get what life I can out of it.)
Even with a 3ohm carto that's still a brief blast at 23.5W. Possibly not enough to damage but not far enough away from that possibility for my liking.
Has anyone else run across this issue? Because this thing should be using the lowest possible voltage when doing its resistance check, not allowing unregulated current through until it gets its bearings. But I wanna know if it's my device or if others have run across this.
Make sure you drip some liquid in there though, it should mitigate the sudden burst of power somewhat and you'll be able to sense the heat from the vapor if you try and take a drag. At least, for the brief time it lives, 'cos at 1.8ohms, if yours does the same as mine, that's nearly 40 watts -- in other words, it'll plink on like a light bulb and die pretty rapidly.
