Technical issue regarding MOSFETs

[Siegrest]

I built a decent box mod with 3x 18650s (total of 8100mAh) and a MOSFET (IRLB3034) controlled switch. However, most guides suggest using a 15k ohm resistor whereas I used a 1k one since I did not have a 15k one at hand. The device has worked flawlessly so far. My multimeter does show 1.6 when I switch it to 200m (the smallest possible) on DCV, but that's hardly an issue. Powered on, it shows 3.97v, which is the exact same as the raw battery output.
Are there any drawbacks to using a resistor this value?
Should I swap it out for a 15k one?

 

[iamthevoice]

Actually, it makes a pretty big difference! The amount of current that is flowing through the switch is determined by the battery voltage divided by the value of that resistor used to turn it off. It would really depend on the switch you are using as well (its rating); running it beyond it capabilities may work for short periods of time, but eventually, the switch will fail. Good luck!

 

[Siegrest]

Thank you for answering so quickly. I'll be sure to use the right resistor this time.

 

[caramel]

Schematic please, we have no idea what that resistor is connected to.

 

[Siegrest]

I used this one:

Spoiler

 

[Mooch]

I built a decent box mod with 3x 18650s (total of 8100mAh) and a MOSFET (IRLB3034) controlled switch. However, most guides suggest using a 15k ohm resistor whereas I used a 1k one since I did not have a 15k one at hand. The device has worked flawlessly so far. My multimeter does show 1.6 when I switch it to 200m (the smallest possible) on DCV, but that's hardly an issue. Powered on, it shows 3.97v, which is the exact same as the raw battery output.
Are there any drawbacks to using a resistor this value?
Should I swap it out for a 15k one?

What's the current rating of your button/switch? The 1k resistor you are using only lets 4.2mA (milliamps) flow through your switch when firing (worst case). This is probably well below the current rating of the button/switch but it's always best to check. Even the tiny "tactile" buttons on boards like the DNA 40 can take, at the least, 20mA.

 

[caramel]

with this schematic it won't make any difference unless your tactile switch is very tiny / can't take much currnet. As mooch has already noticed, this would be unusual.

My concern with this schematic is with the batteries directly connected in parallel, with no diodes or some other balancing scheme.

 

[Siegrest]

Well, about that. When I first went and purchased a switch I didn't think much of the amps or voltages it could tolerate, the only thing that mattered was it looking nice and sleek:

Spoiler

On a second look at the technical details of the switch I discovered it was rated at 3A/250VAC, which should be plenty, I suppose?

 

[caramel]

More than plenty

 

[Siegrest]

Thanks for all the support. Though, I'll still swap out for a 15k resistor, just to be safe.

 

[Mooch]

You can do the swap, it won't hurt. But you're only passing tiny, tiny fraction of what the switch can handle. It will last a lifetime even if you use a 100 ohm resistor.

 

[Mooch]

BTW, nice switch!

 

[Siegrest]

That it is! And a cheap one, also. If anyone's interested, these are the parts I used:
Housing $7.99
Switch $2.36
MOSFET $0.99
Altohether $12, these items come with free shipping.