voltage question

[mokeife]

hello everyone i just got a series mech and i love it however i have some questions about voltage. my first build i did was 11 wraps of 24 gauge and came in at 7.4 volts next i tried a 10 wrap 24 gauge and it came in at 7.8 volts. now i wanted something a little bit hotter so i took 1more wrap off so now i have 9 wraps and this time it came in at 7.5 volts. now why did my voltage increase when i took a wrap off once then the next time it decreased...? any ideas... 11 wraps 7.4 volts, 10 wraps 7.8 volts,9 wraps 7.5 volts ps. this was tested with fresh batteries which came in a 4.1 volts

 

[SirRichardRear]

hello everyone i just got a series mech and i love it however i have some questions about voltage. my first build i did was 11 wraps of 24 gauge and came in at 7.4 volts next i tried a 10 wrap 24 gauge and it came in at 7.8 volts. now i wanted something a little bit hotter so i took 1more wrap off so now i have 9 wraps and this time it came in at 7.5 volts. now why did my voltage increase when i took a wrap off once then the next time it decreased...? any ideas... 11 wraps 7.4 volts, 10 wraps 7.8 volts,9 wraps 7.5 volts ps. this was tested with fresh batteries which came in a 4.1 volts

your build doesn't decide voltage. your build decides resistance.
your voltage will vary with a mech based on the battery charge level. a fresh pair of batteries fully charged will give you 8.4 volts and that will decrease as you use it.

based on your first build (assuming single coil and kenthal and estimating a 3mm ID) it should be about 1 ohm resistance which is about 70 watts and 8.4 amps. Not really an ideal set up TBH. Either way, you really shouldn't be using a mech if you aren't aware of all of this. A regulated mod will suit you much better.

Also if you wanted more build advice, ti would be helpful to know what atomizer and what batteries you are using. Pics also speak 1000 words

 

[mokeife]

this is a dual coil setup the 9 wrap i have in now comes in a .41 however i noticed that my voltage varies a little bit with fresh batteries. and yes i am aware that it decreases as you use it i was just wondering what caused the differences in voltage i was getting i am using a twisted messes squared dripper

 

[mokeife]

im using lg hb6s and i will post some pics in a moment

 

[mokeife]

 

[mokeife]

what determines voltage? or voltage drop i should say. i was under the impression that the lower the resistance the less the voltage drop.. and why does it change when i change the build?

 

[SirRichardRear]

this is a dual coil setup the 9 wrap i have in now comes in a .41 however i noticed that my voltage varies a little bit with fresh batteries. and yes i am aware that it decreases as you use it i was just wondering what caused the differences in voltage i was getting i am using a twisted messes squared dripper

im using lg hb6s and i will post some pics in a moment

what determines voltage? or voltage drop i should say and why does it change when i change the build?

well 1st off LG HB6 are great batteries for a mech. its a 30 amp battery. but downside is low mah (aka low battery life)

for your set up fully charged batteries are 8.4 volts. which would equate to 172 watts and 20.5 amps. so it's safe for those batteries.

where are you reading the battery voltage from? the voltage is only effected by the charge of the batteries and nothing else. fully charged each will be 4.2 so together in series 8.4 volts. every time you take a hit that number goes down. thats the only thing affecting voltage.

 

[mokeife]

i tested the voltage drop using a multimeter i just put it acrooss the negative and positive terminals i was just curious as to why it was changing with no real pattern to it sometimes it would go up sometimes it would go down. ps ive read online that the lower your resistance the less voltage drop you have so your build must have some effect on voltage no?

 

[SirRichardRear]

i tested the voltage drop using a multimeter i just put it acrooss the negative and positive terminals i was just curious as to why it was changing with no real pattern to it sometimes it would go up sometimes it would go down

probably your MM connections. Did you try alligator clips? also don't forget mech mods will have some voltage drops across the way. between the mod and the RDA and the RDA and it's coils. Better mech mods have very little drop. worse ones have a lot. My friend brought this wooden mech box one time and it lost a whole volt lol. his fully charged batteries were putting out 3.2 vots to the RDA, it wouldn't get any vapor. after I showed him that he returned it and got a regulated mod.

 

[mokeife]

no i did not try aligator clips i am losing close to a volt but this is a series mod im assuming your friends is a paralell? because losing a volt on a paralell mod would be much more than losing a volt on a series mod. ps ive read online that the lower your resistance the less voltage drop you have so your build must have some effect on voltage no? ps what is a mm connection?

 

[SirRichardRear]

no i did not try aligator clips i am losing close to a volt but this is a series mod im assuming your friends is a paralell? because losing a volt on a paralell mod would be much more than losing a volt on a series mod. ps ive read online that the lower your resistance the less voltage drop you have so your build must have some effect on voltage no? ps what is a mm connection?

yeah my friends was a parallel. should have gotten 4.2 volts give or take .1
Yours is a series so you should have 8.4 give or take .1 for voltage drop
MM = Multimeter. if your leads don't make a good connection it'll read voltage wrong. alligator clips work great for making a good connection that stays on

 

[mokeife]

im getting about .7-.8 voltage drop not the .1 you speak of where is all this coming from? all my conections are copper

 

[SirRichardRear]

im getting about .7-.8 voltage drop not the .1 you speak of where is all this coming from? all my conections are copper

I couldn't tell you where it's coming from. you'd have to meter every connection one by one starting with the 1st until you find it.
Have you tried another RDA? if another RDA works at least you know it's the box, if it doesn't work it's somewhere in the box.

 

[mokeife]

I couldn't tell you where it's coming from. you'd have to meter every connection one by one starting with the 1st until you find it.
Have you tried another RDA? if another RDA works at least you know it's the box, if it doesn't work it's somewhere in the box.

i lose about the same with my other rda

 

[SirRichardRear]

i lose about the same with my other rda

Then it's the mod losing the voltage. Gotta check voltage at every connection to see where it's losing

Sent from my SM-G935V using Tapatalk

 

[BoomStick]

When you measure from positive to negative at the coils, you're measuring the voltage the coils are dropping (consuming). Not what the batteries are supplying. Forget about that measurement. For our purposes it's kind of meaningless.

 

[mokeife]

When you measure from positive to negative at the coils, you're measuring the voltage the coils are dropping (consuming). Not what the batteries are supplying. Forget about that measurement. For our purposes it's kind of meaningless.

what about one of those inline voltage meters does that take the correct reading?

 

[smacksy]

I would try using an inline voltmeter like this..I used this one alot when I was into mech mods..don't use it much anymore since these high powered VW box mods came out..

Sent from my XT1585 using Tapatalk

 

[fq06]

You do get voltage drop from all of the connections adding resistance but you are seeing voltage sag from the batteries.
Lower resistance, higher amp draw, more stress on the battery, the lower your voltage will drop down (sag) when you hit the fire button. When you let go of the fire button the batteries voltage recovers to it's resting voltage, say 4.1 per cell or whatever it's at after being run a couple times.

 

[nightshard]

The cumulative resistance of the coil, the mod and the battery determines voltage drop, but changing the coil resistance in order to change voltage drop is the wrong way to go at it.
Tell us what wattage range you're aiming for and we'll tell you what resistance to aim for.

 

[mokeife]

The cumulative resistance of the coil, the mod and the battery determines voltage drop, but changing the coil resistance in order to change voltage drop is the wrong way to go at it.
Tell us what wattage range you're aiming for and we'll tell you what resistance to aim for.

i already have a build that i like its 9 wraps of 24 gauge which ohms out to around.41. i was just curious as to what factors effect voltage drop thanks

 

[mokeife]

does battery charge effect how much voltage drop you get?

 

[SirRichardRear]

does battery charge effect how much voltage drop you get?

the weaker the batteries, the less voltage they put out

 

[mokeife]

the weaker the batteries, the less voltage they put out

i understand that just curious if the actual voltage drop changes when the batteries get weaker

 

[SirRichardRear]

i understand that just curious if the actual voltage drop changes when the batteries get weaker

The voltage should only drop when the load (amps) get too much for it to maintain. Charge shouldn't effect drop

 

[fq06]

Watts / volts = amps

50w/4.1v= 12.19a
50w/3.6v= 13.88a

The higher the amp load on a cell the more voltage SAG you will see.

Voltage drop references the loss of efficiency you get from multiple connections.
Sag is the effect of pulling power from a cell.

 

[fq06]

There will be voltage sag no matter what when you hit the fire button.
The lower the charge level (voltage), the more sag as a percentage from that level but there is no way to not have voltage sag to some measurable degree even if only asking for 1 watt.

 

[fq06]

Voltage drop is a fixed value, if the connections from cell to wire result in a 0.1v drop or 0.2v drop or 0.3v drop, that will not change no matter what the cells voltage is at.
That loss or drop exists without a battery in the device.

Voltage sag is something completely different and is what your original question was asking about

 

[fq06]

https://en.m.wikipedia.org/wiki/Voltage_sag

 

[HondaDavidson]

Do you have a car???? Think of sag as going up a hill, and not being able to give it more gas.... The steeper the hill the more gravity slows the car. Same thing happens with a mod, the hill being your build.

 

[mokeife]

so the little voltmeter inside my mod is that reading voltage sag or drop?

 

[SirRichardRear]

so the little voltmeter inside my mod is that reading voltage sag or drop?

how about telling us what mod you are using?

 

[mokeife]

how about telling us what mod you are using?

its a custom series/parallel unregulated device made by beau renfro

 

[mokeife]

 

[fq06]

That is sag. It's the live voltage of the cell.

When you hit the fire button, voltage decreases considerably. As soon as you let go of the fire button, it recovers to the resting voltage of the cell.

 

[fq06]

That's a big fuckin mod lol

 

[mokeife]

That's a big fuckin mod lol

lol i love it hits like a champ

 

[mokeife]

any reason why the SAG would change sometimes it dips 1 volt somtimes up to 1.5 volts ? this is all with the same build

 

[mokeife]

it usually dips .95-1.2v

 

[SirRichardRear]

any reason why the SAG would change sometimes it dips 1 volt somtimes up to 1.5 volts ? this is all with the same build

it could only be the batteries themselves. what kind are you using. you said HB6 but based on the pic they aren't. (HB6 are pink or ivory) those are green. based on the color and the "1500mah" label i'd have to guess LG HB2 or Sony VCT3? how old are the batteries, maybe they are just going bad?

 

[mokeife]

it could only be the batteries themselves. what kind are you using. you said HB6 but based on the pic they aren't. (HB6 are pink or ivory) those are green. based on the color and the "1500mah" label i'd have to guess LG HB2 or Sony VCT3? how old are the batteries, maybe they are just going bad?

they are lg hb2s i also have a pair of lg hb6 and their both new i got the hb2s yesterday lol

 

[SirRichardRear]

they are lg hb2s i also have a pair of lg hb6 and their both new i got the hb2s yesterday lol

they shouldn't be dropping. Even at 60 amps they don't sag. not until 70 amps do they sag that much

 

[mokeife]

i got a .37 build but thats still a ways away from 70 amps and they sag on all my mods

 

[SirRichardRear]

i got a .37 build but thats still a ways away from 70 amps and they sag on all my mods

full charged batteries would be about 22 amps. well within the range for HB2 batteries. They shouldn't sag at all. Where did you get the batteries from?

 

[mokeife]

all my cells sag that much lg hb6 lg hb2 and lg he2s now im confused

 

[mokeife]

i got them from a pretty reputable dealer near my house and the other ones i got online at evcigarettes

 

[mokeife]

i even have another volt meter and it gives the same reading so somethings not right

 

[SirRichardRear]

all my cells sag that much lg hb6 lg hb2 and lg he2s now im confused

Did you try hooking up a multi meter to make sure the voltage meter on the mod is reading correctly?
There could be protections in the mod as well or an issue with the mod. looks like the wires go through the board then to the switch then the atomizer (hard to tell from the pic)

 

[SirRichardRear]

i got them from a pretty reputable dealer near my house and the other ones i got online at evcigarettes

i even have another volt meter and it gives the same reading so somethings not right

maybe a bad batch of batteries?

 

[mokeife]

That is sag. It's the live voltage of the cell.

When you hit the fire button, voltage decreases considerably. As soon as you let go of the fire button, it recovers to the resting voltage of the cell.

does it always drop considerably? or are all my cells fake whats going on here?