Battery amp advice

[DaveP]

I agree.

Things start to happen Very Fast when the Denominator of a Fraction approaches Zero.

A person should also have a Very Accurate way to Measure Ohms.

Check out this Sub-Ohm Chart I made in another Thread...

My Provari may read 2.1 ohms on a given coil, as will my Segelei Zmax. My little digital 510 thread ohmmeter box with the neat blue LED display with two digits to the right of zero will say 2.17 ohms on the same coil. When you get close to zero, the curve drops in a hurry. Most coils rise in resistance as we vape. What would happen if heat related distortion caused a coil short at .13 ohms?

 

[zoiDman]

My Provari may read 2.1 ohms on a given coil, as will my Segelei Zmax. My little digital 510 thread ohmmeter box with the neat blue LED display will say 2.17 ohms on the same coil. When you get close to zero, the curve drops in a hurry. Most coils rise in resistance as we vape. What would happen if a coil short occurred at .13 ohms?

+/- .05 Ohms Isn't a huge deal when you are in the >1.8 ohm range. Same with the Actual Outputted Voltage of a APV.

But starts to become Very Critical when the Ohms get Very Small.

I'm not sure why people need to Push Things right up to the Cliff Edge with Sub-Ohms? But if they Do, they should at Least Invest in a Precision DMM.

 

[zoiDman]

... What would happen if a coil short occurred at .13 ohms?

All the Possible Electrons would Try to Move at One Time.

And there is a Boat Load of Potential Electrons in a 18650 Li-Ion Battery.

 

[rufus1138]

just curious here but with the ultimate result being huge clouds, would it help the buffer/headroom/safety factor if you were to run a different style battery with a higher voltage so that you could get equivalent heat out of a higher resistance and thus stay away from the black hole part of the wattage curve where a problem will almost certainly give you a dead short? take a look at some battery specs from the rc world. why would it be that hard to make a box mechanical mod that had a battery well for this thing?

3200mAh 3S 11.1V 30C LiPo, 12AWG EC3 (EFLB32003S30): E-flite - Advancing Electric Flight

 

[zoiDman]

just curious here but with the ultimate result being huge clouds, would it help the buffer/headroom/safety factor if you were to run a different style battery with a higher voltage so that you could get equivalent heat out of a higher resistance and thus stay away from the black hole part of the wattage curve where a problem will almost certainly give you a dead short? take a look at some battery specs from the rc world. why would it be that hard to make a box mechanical mod that had a battery well for this thing?

3200mAh 3S 11.1V 30C LiPo, 12AWG EC3 (EFLB32003S30): E-flite - Advancing Electric Flight

What happens when a LiPo battery like this Fails?

A Small Puff of Smoke? A Big KaBoom? Or maybe something In-between?

 

[DaveP]

just curious here but with the ultimate result being huge clouds, would it help the buffer/headroom/safety factor if you were to run a different style battery with a higher voltage so that you could get equivalent heat out of a higher resistance and thus stay away from the black hole part of the wattage curve where a problem will almost certainly give you a dead short? take a look at some battery specs from the rc world. why would it be that hard to make a box mechanical mod that had a battery well for this thing?

3200mAh 3S 11.1V 30C LiPo, 12AWG EC3 (EFLB32003S30): E-flite - Advancing Electric Flight

I suppose a car battery could take a short from a delicate 28ga Kanthal coil. It would just blow hot metal and wicking up the air tube. Cough, Cough !

 

[rufus1138]

I suppose a car battery could take a short from a delicate 28ga Kanthal coil. It would just blow hot metal and wicking up the air tube. Cough, Cough !

true, obviously you have to be careful with the coil build, just like i suspect you would on any mod running a 30a battery already, these batteries tho would have to have a dead short to vent and then they dont have a metal case to hold pressure, they're soft packs and admittedly have to be treated with a little more care to prevent rupturing the cells but their failure mode is just heat, they can start fires but they wont vent violently after building up pressure like the 18650 style will. the point here is you can do the math and get the heat needed for cloud chasing and hold it at higher ohms so that if a partial short occurs it wont drop you from .1 to .05, instead you will be running 4.1 ohms to get 30 watts while drawing 2.7 amps of the rated 96 amp continuous rating, at that setting you would get amazing run time and suffering a "half short" which was discussed earlier that could spike the amps on an insane level on the sony vtc5, in this scenario you would drop to 2.05 ohms and pull only 5.4 amps, jump to 60 watts, and still be nowhere near your threshold of 96 amps, hell the continuous rating produces 1065.6 watts at .11 ohms