The VAMO battery thread

[kiwivap]

I remember Kiwivap saying it still draws power from the battery when not in use but I can't remember how much of a draw.

Its not much of a draw stand-by, here's the comparisons from Mountain Prophet:
Zmax V2 RMS 0.11 mA
Vamo VV / VW 0.15 mA
Provari 0.96 mA

 

[kiwivap]

The Vamo shows a noticeable degradation of performance when the battery goes below 3.5V, so I wouldn't care too much about any residual charge

The Vamo has a low voltage cut off at 3.2 volts on the battery . Mine will suddenly cut off at 3.2. (edited post due to mix up).

 

[meli.]

I got my 34g Kanthal A1 this morning, crickey, I'm struggling a little with these wraps. 4/3 wraps on a 1.8mm cotton hybrid wick, pitch between wraps is about the same, the coil itself is no more than 6mm in height, came up as a whopping 3.5Ω's. Tested with multimeter still the same. Everything I've read suggests 4 wraps will be about 2.5Ω's. Anything less and it's nasty vaping. I'm at a loss as to why this happening. By all accounts this should read less than 3Ω's, shouldn't it?

I know this is a little off topic, please bear with me.

 

[kiwivap]

I got my 34g Kanthal A1 this morning, crickey, I'm struggling a little with these wraps. 4/3 wraps on a 1.8mm cotton hybrid wick, pitch between wraps is about the same, the coil itself is no more than 6mm in height, came up as a whopping 3.5Ω's. Tested with multimeter still the same. Everything I've read suggests 4 wraps will be about 2.5Ω's. Anything less and it's nasty vaping. I'm at a loss as to why this happening. By all accounts this should read less than 3Ω's, shouldn't it?

I know this is a little off topic, please bear with me.

I haven't used cotton hybrid - just ss mesh by itself. A 4/3 wrap gives me 2.8 - 3.0 ohms. But it isn't just the no. of wraps, its the wire length that gives the resistance apparently. So its possible you're at 3.5 ohms. Sorry I can't be more specifically helpful.

 

[xpen]

Actually mine consistently cuts off at 3.2V, sharp... But it may well be the case that 3.4V under load (3+ ohms in my case) ends up showing 3.2V.

But as said below 3.5V vaping gets noticeably 'underpowered', thus at that point I normally just swap out the battery and be done with it.

My guess being the Vamo's PWM is a little less efficient than it should... But then again, for the price I can't really complain

The Vamo has a low voltage cut off at 3.4 volts on the battery. So below 3.5 you will notice a difference. Mine will suddenly cut off at 3.4. I can fire it a couple of times after that but then it stops.

 

[xpen]

It makes sense, that's what I was saying a few posts ago... 0.15mm Kanthal A means about 0.8Ω/cm, give or take, so ideally you'd need to keep the total wire length, all included up to the posts, below 4cm.

All I can offer is that 4/3 wraps on a 2.5mm drill bit makes 3Ω almost invariably for me, +/- 0.2Ω depending on how much I'm able to tighten the coils (I mean with pliers, not by hand ). Then the game moves to keeping the wire 'tails' as short as possible, which in an AGA-T configuration may be a bit more problematic than on my A7's...

But then, why should 3+ Ω be a problem? Your battery drain will be less, even though not by far, and the vamo takes care of your wattage being the same anyway. I always suspected the Vamo performance to decrease slightly beyond 3.5Ω load (I have no hard proof of that, only my feeling) but anything around 3Ω does fine for me any day.

If you can't really tame it to the point you like, then I'd suggest you to either think about NR wire for the 'last mile' - which would be a PITA IMO - or perhaps to consider 0.18mm wire, which stays around 0.55Ω/cm.

Let us know how it ends up.


P.S. please be careful about tightening the 0.15mm wire by hand, it cuts!!! And please don't ask me how do I know...

I got my 34g Kanthal A1 this morning, crickey, I'm struggling a little with these wraps. 4/3 wraps on a 1.8mm cotton hybrid wick, pitch between wraps is about the same, the coil itself is no more than 6mm in height, came up as a whopping 3.5Ω's. Tested with multimeter still the same. Everything I've read suggests 4 wraps will be about 2.5Ω's. Anything less and it's nasty vaping. I'm at a loss as to why this happening. By all accounts this should read less than 3Ω's, shouldn't it?

I know this is a little off topic, please bear with me.

 

[meli.]

Mine does exactly the same Xpen, cuts out at 3.2v. Test battery with MM and it's bang on 3.2v. But yes it does start to drop off at 3.5v, I've tuned into this too so either I swap out batteries or it's prime time to sit down and setup coils. Only today I have been pulling my hair out.

I use pliers/ tweezers, drill bit /Petar K method. Unoxidized wick. 3 Juice burns. Pulsing. A OK. Today, I was in hurry to set up, I chose to wrap the wick with thin layer of cotton wool, fantastic, positive leg is good, everything is good. I just can't get the coil less than 3.5Ω, it' isn't bad vape by any means but I do find it different, and I'm a bit of stickler for getting things right. When I can't understand why something is not behaving the way it should or perhaps the way I think it should then it drives me a little nuts. I know I'm probably overlooking something but Fear not, I'll get there. Eventually. Even if I'm completely bald by then.

 

[xpen]

Yes, I think 3.2V should be the proper vamo cut-off value, judging on what I've read so far and on our own experience.

Mine does exactly the same Xpen, cuts out at 3.2v. Test battery with MM and it's bang on 3.2v. But yes it does start to drop off at 3.5v, I've tuned into this too so either I swap out batteries or it's prime time to sit down and setup coils. (...)

Sorry to hear about your wiring troubles... I do understand what it means when things don't behave as they should (according to one's parameters, that is ), though.

Have you tried to take a few measurements? for instance, how many Ω for say 10cm of 0.15mm wire? Or, how many cm for your AGA coil setup, all included? I'm really wondering in fact whether you can achieve less than 3Ω at all, with that wire and 4/3 wraps, let alone 2.5Ω...

So please at least double-check if the challenge is doable, before getting bald!

Note: I'm sure you already know this, but you don't need to cut the wire for measuring its resistance by multimeter: it will only show the resistance of the wire in between the probes.

(...) I use pliers/ tweezers, drill bit /Petar K method. Unoxidized wick. 3 Juice burns. Pulsing. A OK. Today, I was in hurry to set up, I chose to wrap the wick with thin layer of cotton wool, fantastic, positive leg is good, everything is good. I just can't get the coil less than 3.5Ω, it' isn't bad vape by any means but I do find it different, and I'm a bit of stickler for getting things right. When I can't understand why something is not behaving the way it should or perhaps the way I think it should then it drives me a little nuts. I know I'm probably overlooking something but Fear not, I'll get there. Eventually. Even if I'm completely bald by then.

 

[kiwivap]

Actually mine consistently cuts off at 3.2V, sharp... But it may well be the case that 3.4V under load (3+ ohms in my case) ends up showing 3.2V.

No, you're right. It is 3.2v. I was vaping a different pv when I wrote that and must have mixed it up in my mind. Sorry! I've told that many people its 3.2 volts before myself. Anyways - I don't notice a drop off until the Vamo hits cut off quite often. I've often vaped it to the cut off and wondered what happened. "No vapor?" But I do sometimes notice around 3.4 volts it is a bit different. Mostly I don't though. I've been caught out while driving a couple of times with hitting the cut off. Great time to try and change a battery, but it has been done.
Sorry about the mix up - I'll edit the post.

 

[kiwivap]

I use pliers/ tweezers, drill bit /Petar K method. Unoxidized wick. 3 Juice burns. Pulsing. A OK. Today, I was in hurry to set up, I chose to wrap the wick with thin layer of cotton wool, fantastic, positive leg is good, everything is good. I just can't get the coil less than 3.5Ω, it' isn't bad vape by any means but I do find it different, and I'm a bit of stickler for getting things right.

Given my mixing things up last night, (it was night here) I just checked my AGA-T+. I have a 4/3 wrap - its 3.0 ohms. I know I've had 2.8 ohms with a 4/3 wrap also. I don't know how long in mm my set up is. My very first coil was 2.6 ohms so I must have had a 3/2 wrap on it. I've only been using 34 awg kanthal for my coils and they don't go over 3.0 ohms unless the coil is unstable. The average wire diameter is 0.0063 in. (0.16002 mm).

3.5 ohms does seem a bit high - have you tried doing a 3/2 wrap and seeing how that vapes?

 

[kiwivap]

Have you tried to take a few measurements? for instance, how many Ω for say 10cm of 0.15mm wire? Or, how many cm for your AGA coil setup, all included? I'm really wondering in fact whether you can achieve less than 3Ω at all, with that wire and 4/3 wraps, let alone 2.5Ω...

2.5 ohms maybe not, 2.8 - 3.0 ohms should be doable, shouldn't it? My kanthal A-1 34g is 0.16mm and I get 2.8-3.0 ohms with a 4/3 wrap -and I've checked it today to make sure.

 

[xpen]

For me the difference is quite noticeable, most of the times I can tell when the battery hits 3.4V without even looking to the display.

Not much of a problem, anyway

No, you're right. It is 3.2v. I was vaping a different pv when I wrote that and must have mixed it up in my mind. Sorry! I've told that many people its 3.2 volts before myself. Anyways - I don't notice a drop off until the Vamo hits cut off quite often. I've often vaped it to the cut off and wondered what happened. "No vapor?" But I do sometimes notice around 3.4 volts it is a bit different. Mostly I don't though. I've been caught out while driving a couple of times with hitting the cut off. Great time to try and change a battery, but it has been done.
Sorry about the mix up - I'll edit the post.

 

[kiwivap]

For me the difference is quite noticeable, most of the times I can tell when the battery hits 3.4V without even looking to the display.

Not much of a problem, anyway

I have another pv that cuts off at 3.4 volts. I think 3.4 volts is pretty good for a cut off point. If the Vamo had a 3.4 cut off I'd be fine with that myself.

 

[xpen]

Actually the wire at hand should be 34.5g/0.15mm, and if it works like mine it's really difficult to achieve less than 3Ω with a 4/3 wraps setup, on a normally sized wick; I normally come up around 3/3.1Ω on a 2x2mm wick.

A quick comparison of Kanthal wires:

0.15mm approx 0.8Ω/cm
0.16mm approx 0.7Ω/cm
0.18mm approx 0.55Ω/cm
0.20mm approx 0.45Ω/cm

Sorry about the O/T

2.5 ohms maybe not, 2.8 - 3.0 ohms should be doable, shouldn't it? My kanthal A-1 34g is 0.16mm and I get 2.8-3.0 ohms with a 4/3 wrap -and I've checked it today to make sure.

 

[kiwivap]

Actually the wire at hand should be 34.5g/0.15mm, and if it works like mine it's really difficult to achieve less than 3Ω with a 4/3 wraps setup, on a normally sized wick; I normally come up around 3/3.1Ω on a 2x2mm wick.

A quick comparison of Kanthal wires:

0.15mm approx 0.8Ω/cm
0.16mm approx 0.7Ω/cm
0.18mm approx 0.55Ω/cm
0.20mm approx 0.45Ω/cm

Sorry about the O/T

I bought mine from Discount Vapers - his specs say

Alloy:
Kanthal A-1
(22% Cr, 5.8% Al, Fe balance)
Gauge:
34 AWG
Average wire diameter:
0.0063 in. (0.16002 mm)
Shape:
Round
Heat treatment:
Annealed (soft)
Resistance (Ohms/ft. @ room temp):
21.1

3.0 ohms is the highest I've had with 4/3 wrap. The one before this was 2.8 ohms. I think perhaps there is some difference in our wire.

 

[meli.]

Kiwi, mine like Xpen's is 0.15mm. Odd.

Xpen, thanks for this little gem:

Note: I'm sure you already know this, but you don't need to cut the wire for measuring its resistance by multimeter: it will only show the resistance of the wire in between the probes.

ROFL, My husband walked in on me whilst I was cursing an inch long strand with MM probes in hand. heh, I did feel a smidge small. Stupid wire just wouldn't hold still!!

I'll go back to the coiling board later and have another go. I'll see if I can drop it to 3Ω. With regard to battery performance and all this fiddling about, I can't really comment yet. Hopefully I can get these coils sorted quickly and make some comparisons soon.

Thank you both, I really do appreciate all the help.

 

[peraspera]

I'll see if I can drop it to 3Ω. With regard to battery performance and all this fiddling about, I can't really comment yet. Hopefully I can get these coils sorted quickly and make some comparisons soon.

I don't know if this info will help but I'm at 2.0 Ω with a 4/3 wrap using 34 gauge Kanthal I bought from temco_industrial_power on eBay. These are the specs:

TEMCo ID: RW0075
Alloy: Kanthal A-1 (22% Cr, 5.8% Al, Fe balance)
Gauge: 34 AWG
Average wire diameter: 0.0063 in. (0.16002 mm)
Weight & length: 100 ft. (0.15 oz.)
Shape: Round
Heat treatment: Annealed (soft)
Resistance (Ohms/ft. @ room temp): 21.1
Melting temperature: 1500°C (2730°F)
Maximum operating temperature: 1400°C (2550°F)
Density: 0.256 lbs. per cubic inch
Specific heat capacity at 20°C (68°F): 0.46 kJ/kg K (0.11 Btu/lb°F)

I don't know if it makes a difference but the Kanthal is attached to the ground screw going clockwise and to the positive post going counter-clockwise. I substituted a spring and washers for the middle nut on my positive post. The edge of the washers stick out 2 mm. from the outer edge of the positive post so the wire is 2 mm. shorter before it makes a contact to the positive connection than it would be just using the nuts.

 

[xpen]

Kiwivap, Peraspera: our 34.5g wire sports about 10/12% more resistance than your 34g (21.1Ω/ft -> 0.7Ω/cm), thus achieving 3Ω with a 4/3 wrap makes for a great success on its own

Meli: I'm sure you'll see some better battery life with resistances around 3Ω

 

[xpen]

2Ω? It seems really low-res, for having used 34g wire in a 4/3 wrap... you must have played some tricks for achieving that

I don't know if this info will help but I'm at 2.0 Ω with a 4/3 wrap using 34 gauge Kanthal I bought from temco_industrial_power on eBay.
(...)
I don't know if it makes a difference but the Kanthal is attached to the ground screw going clockwise and to the positive post going counter-clockwise. I substituted a spring and washers for the middle nut on my positive post. The edge of the washers stick out 2 mm. from the outer edge of the positive post so the wire is 2 mm. shorter before it makes a contact to the positive connection than it would be just using the nuts.

 

[peraspera]

2Ω? It seems really low-res, for having used 34g wire in a 4/3 wrap... you must have played some tricks for achieving that

Ignorance rather than skill would be responsible for any tricks. However, I did forget to mention that I used a clockwise wrap. I also wrapped the coil around the wick directly rather than using the Petar K method of wrapping it around a drill bit. I don't know if it matters or not but I did not oxidize my 500 mesh 1 1/2" x 3" wick until after it was rolled. Then I just oxidized the part where the coil goes and a little on the very bottom.