Power resistors for 7.4v and 6.0v battery modding

[SLoWPoKeSE]

I've been messing with some battery modding. I use the DSE-901 atomizers which have 3.3 ohm resistance. Alot of ppl on here are spending lots of time installing voltage regulators, but I think if you just add in the right type of resistor into the circuit you can up your wattage without overpowering it with your batteries. From my personal experience so far, using a 2xCR2 6v mod my atty's would last roughly 1 day and then burn out. I also made a box for 2x14500 7.4v and *stupidly* hooked up an atty which lasted about 1 second. Here are some tables with the theoretical values of my setup before and after adding in a power resistor. When I get in my order I will re-post about the effect of these on my atty-life and power/taste. My hypothesis is that the 901 atty's will have the best balance of power/taste vs. lifespan at 7-9 watts.

Wattage Current Voltage Resistance
Total 10.91 1.82 6 3.3
Atty 10.91 1.82 6 3.3
Resistor 0 1.82 0 0

Wattage Current Voltage Resistance
Total 16.59 2.24 7.4 3.3
Atty 16.59 2.24 7.4 3.3
Resistor 0 2.24 0 0

Wattage Current Voltage Resistance
Total 9.47 1.58 6 3.8
Atty 8.23 1.58 5.21 3.3
Resistor 1.25 1.58 0.79 0.5

Wattage Current Voltage Resistance
Total 12.17 1.64 7.4 4.5
Atty 8.92 1.64 5.43 3.3
Resistor 3.25 1.64 1.97 1.2

I found the 1.2ohm and .5ohm resistors rated at 4watt at allelectronics.com

 

[Dave_uk]

but I think if you just add in the right type of resistor into the circuit you can up your wattage without overpowering it with your batteries.

Your 100% correct in that your method works..

But...

Doing it by that method is wasteful of your batteries power, as your powering / heating the resistor as well as the atty.

A mosfet would be far more efficent.

My hypothesis is that the 901 atty's will have the best balance of power/taste vs. lifespan at 7-9 watts

Sounds good.

A 901 standard atty is at about 3.7 ohms, if you want to run it in your 'ideal' wattage range then a 5v 'ish regulator could be a good option.

 

[SLoWPoKeSE]

Just had a thought... does anyone have any thoughts about using a 14500 3.7v with a NiMH 1.2v for a 4.9v pack? Is there some reason you shouldn't mix these two types? I think they have similar mAh ratings.

 

[5cardstud]

The guys to ask is Scottbee or Connman and there are some other gurus here. Wait till they read this post and they can help you. Welcome to ECF.

 

[Dave_uk]

Is there some reason you shouldn't mix these two types?

Yes... stacking batteries requires them to be the same, this is due to the current needs to be flowing through them all equally,

 

[SLoWPoKeSE]

Well...I did try stacking them that way (only b/c waiting on a shipment) and I didn't blow my face off. Not really my favorite solution but it did work at least for these few days. I got my 2x14500 box made today with 1.2ohm 4watt resistor in-line. And I'm pretty impressed with it. I know I'm wasting more battery power than if using a mosfet. I know also that the voltage is not going to be consistent like a 5v regulator...but it works for me. I'm a noob I admit it and if I have to switch batteries more often I don't care b/c it works good and that makes me happy. At near full charge I get 7v under load which brings 8.575 watts on my atty which measures 2.8ohms. At 6 hours of heavy usage I'm getting 5.7v under load for 5 seconds which brings 5.685 watts to the atty. I think I'll be set by switching them once midday. It's not the elegant solution but it does have merit in that it's very very simple.