hey yall, Currently I am building a new mod that i'm hoping to get 8.4v and 120 max amp draw, with 6 batteries rated at 4.2v and 40A each.
>see diagram
my biggest question is how big of a resistor should i use with my Mosfet? and feel free to double check my work; i want to be safe, and accurate.
>>8709951
>AJ trying this hard
>>8709951
Theory (aka wishful thinking):
>how big of a resistor?
divide voltage by current, 70 mΩ
Reality:
>4.2V
only at zero load
>195A
for a microsecond?
RTFDATASHEETS
>>8709951
emf of batteries?
>>8710160
batteries
>>8710163
mhmm the internal resistance should be labeled on the battery, as it is on most..
confused?
>>8710156
why 4.v in reality? didn't i wire the batteries in series parallel?
>>8710168
lol misread "of" as "or"https://www.amazon.com/O-B18650-40R-Battery-2600mAh-Rechargeable-Batteries/dp/B01NAPANA1/ref=sr_1_2?ie=UTF8&qid=1488271610&sr=8-2&keywords=vape+batteries
here's the link to the batteries, no mention of internal resistance will look more
>>8710172
>https://www.amazon.com/O-B18650-40R-Battery-2600mAh-Rechargeable-Batteries/dp/B01NAPANA1/ref=sr_1_2?ie=UTF8&qid=1488271610&sr=8-2&keywords=vape+batteries
No worries. I dont want to spend the time doing you're problem, but you'll need to know the internal resistance as it will affect overall current and voltage outputs..
>>8710175
Looks like you'll have to figure it out with a multimeter using the ohm setting or with a circuit and known resistor value.
http://physicsnet.co.uk/a-level-physics-as-a2/current-electricity/electromotive-force-and-internal-resistance/
from looking around some, a typical internal resistance is ~35mR
>>8710191
then kirkoff's laws and basic series and prallel circuit physics should make this an easy problemo. Cept your unknown is a resistance in series and not a total resistance.
>>8710201
the functioning part of the circuit has a resistance of .07 (a hypothetical low) but in average use will be .1 ohms