4.7v passthru prob.

[Johnny2puffs]

Health Cabin has a variable voltage blank bat to 4.7v and they say it works on a computer USB port.
How can this work as the port only supplies 500ma? At 1.5ohm atty and 4.7v you need at least 3.13amps. Am I correct?

 

[Mjolnir07]

Don't have one of those, but I can tell you in all certainty that from my experience with multiple pass-thru's there's probably nothing in that batt that's going to make it pull significant voltage from a computer usb port. As I'm sure we've all discovered, an AC adapter is the only proper way to make a passthru do the job.

On a related note, however, I did discover that a car DC to USB adaptor works fantastically with pass-thru's.

 

[SteelJan]

I'm looking at what I think is what you are looking at, is this it? [V.V. Passthrough] 650/900mAh(Variable Volt) USB battery(Passthrough) for 510/eGo - $21.00 : Healthcabin Electronic Cigarettes - Wholesale and Retail-- Goes up to 4.2V, not 4.7V. Anyhoo, with this one, you are not vaping on the USB power, it's just recharging the battery, you are actually vaping off of the battery on this one.

 

[Mjolnir07]

Oh hey SteelJan!

Before I became a member of ECF I relied almost exclusively on your youtube reviews, I guess you could say I'm a fan!

Also that's ingenious, but personally I'd still prefer a straight power draw, I guess that makes this thing pretty unique as a pass-thru.

 

[Johnny2puffs]

I'm looking at what I think is what you are looking at, is this it? [V.V. Passthrough] 650/900mAh(Variable Volt) USB battery(Passthrough) for 510/eGo - $21.00 : Healthcabin Electronic Cigarettes - Wholesale and Retail-- Goes up to 4.2V, not 4.7V. Anyhoo, with this one, you are not vaping on the USB power, it's just recharging the battery, you are actually vaping off of the battery on this one.

510/eGo (3.2V/ 3.7V/ 4.2V/4.7V) Variable Passthrough V2 - $17.00 : Healthcabin Electronic Cigarettes - Wholesale and Retail--
The above is what I was looking at. No bat. Uses power from laptop USB port. This just simply cannot work.
So you vape off the laptop at 500ma? This will hardly warm up the coil. Or it will draw the odd 2500ma for a fraction of a second and fry the laptop.
For $17.00, you get to fry your own laptop??

 

[WillyB]

510/eGo (3.2V/ 3.7V/ 4.2V/4.7V) Variable Passthrough V2 - $17.00 : Healthcabin Electronic Cigarettes - Wholesale and Retail--
The above is what I was looking at. No bat. Uses power from laptop USB port. This just simply cannot work.

You sure? It will depend on the ohms. With a standard Boge carto you need about 1.5A to get 4.7V. Is that possible from a computer port? Sure is.

 

[Johnny2puffs]

You sure? It will depend on the ohms. With a standard Boge carto you need about 1.5A to get 4.7V. Is that possible from a computer port? Sure is.

I think you mean that you need 4.7v to get 1.5A from a Boge carto.
The voltage is always fixed. The amps vary with carto resistance.
1.5A from a USB port??? Forget it. Cannot happen.

 

[markfm]

It can happen, just that it is generally not smart to do, you have a reasonable risk of make the laptop go poof (or at least the USB port, or the PC power supply, or...), else it will actually be doing a voltage sag (part of what can lead to the later early failure).

The USB spec doesn't guaranty more than 500 mA available on a port, though some PCs may indeed be able to supply a decent amount more, and by the time you're pulling in 1.6A to handle a 3 ohm carto you are likely really over-stressing things. I have run a straight passthrough off of a Dell PC port, for a short time before I got my 2A USB power supplies; a few ports could handle a 3 ohm carto (others on the same machine didn't), and none of them could fire a 2.5 ohm carto at all.

Walmart online, get the IQ dual 2 amp USB power supply, under $10. I ran my phone charger and a passthrough off of one for many months, no problems. It has two USB outlets, can source a total of 2A between the two ports.

 

[Johnny2puffs]

Ok. that is a USB3 port. It can handle 1A max. Yes, an external powered 2A supply. This is simply too little for vaping as we do with 1.5ohm atty. A moderate vape without a TH is not worth it. Cost wise as well.