HV batteries for Omega

[rotaryrocket]

Hi all,

I know this has been discussed, but with the increased availability of HV atomizers I thought I would ask the question (again).
I want to try and keep it simple and use the same batteries, chargers, etc. for my mods but most importantly I want to be as safe as possible.
So, to the question. With the Omega, this is the battery I am looking at:

AW RCR123a Protected 750 mAh Battery

I know these will be at 4.2 volts coming off the charger but will drop down to 3.6 volts, correct?
So according to Ohm's law with two of these stacked and a 4.5 ohm atty I believe I would be looking at 7.4 volts | 1.65 amps | 12.2 watts power.
Unless I'm mistaken one of the advantages here is the higher power but low amperage which should help with atomizer life.
Would these batteries be a good choice in this configuration? Are they going to be stressed here or is the amperage OK for their discharge rate?

Thanks in advance,
Mark

 

[jmanning]

Those are probably the best standard lithium-ion RCR123As available, however, at the AW 2C discharge rating, you would be slightly overstressing those. The best for 7.4v would probably be AW IMR16340 550 mAh IMR CR123 size LiMN Rechargeable Lithium Battery rated at 8C.

 

[Quick1]

but most importantly I want to be as safe as possible.

AW RCR123a Protected 750 mAh Battery

Hard to beat AW protected batteries. That's about as safe as you can get. From a safety and current perspective they are protected against over discharge rate. Even if you are drawing over the rated discharge rate they will still be safe/protected. Over driving them (you would not be doing that with a 4.5Ω load) will only have the effect of reducing their total life somewhat.

I know these will be at 4.2 volts coming off the charger but will drop down to 3.6 volts, correct?

No (yes?). They will come off the charger at 4.2v. After you use them for a number of hours they will drop down to 3.6v ...and are ready to be recharged.

So according to Ohm's law with two of these stacked and a 4.5 ohm atty I believe I would be looking at 7.4 volts | 1.65 amps | 12.2 watts power.
Unless I'm mistaken one of the advantages here is the higher power but low amperage which should help with atomizer life.

No. It's primarily temperature that will effect atomizer/coil life. In general, HV atomizers do not last any longer than regular ones. The only reason for HV atomizers is to allow for more choices in getting a desired wattage. Until recently there weren't any variable voltage pv's so you were constrained by the fixed voltage's of the battery chemistry. 3.7v or 7.4v (stacked). Then there were 3.7v batteries that had circuitry to regulate to 3v. You could stack 2 of those for 6v. With the higher voltages you really needed some higher resistance atomizers to bring it into that range for vaping. With a HV (higher resistance) selection you had more granularity to mix and match voltage with resistance for the wattage you prefer. "HV" does not imply Heavy Duty.

Would these batteries be a good choice in this configuration? Are they going to be stressed here or is the amperage OK for their discharge rate?

Those batteries would be a great choice. Make sure they fit... I think the max you want to go in the Omega is 68mm? so maybe check the length with Chad (I seem to remember that they are fine at 68.6mm). Amps/discharge rate is fine. You're not really even going over the rated discharge rate. And it will cut off if you attempt to draw more than would be safe. Keep in mind that the protection circuits are set to protect from a continuous over draw. If they were set to protect from some burst rate (like a few seconds in our application they would be higher). It is internal heat in the battery that is being protected against and that is done indirectly by monitoring the current.[/QUOTE]


I'm not a fan of the IMR batteries. Or the lipos or the lifepo4s. Yes they are safe chemistry but you can still burn yourself, you can melt your spring, and they require a lot more care and attention. For example you can ruin the battery by running it down too low. Sure the vapor is going to stop before that but what if you're firing it iinadvertently in your pocket or bag. Batteries are not inexpensive and I'd rather not have to worry about it. As far as overstressing them. I wouldn't worry about it. If you are draining and recharging them once a day I'd still expect them to last well over a year.

 

[rotaryrocket]

Just wanted to say thanks to both of you for the great info. I think a lot of us are just starting to learn a lot about the different battery options and how they integrate into pv's as far as amp draw, different types of batts, etc. and the safety aspects of each. So the more info we can get out here for everyone, the better. Just because a battery is 3v or 3.7v, doesn't necessarily mean it will be the best choice for a unique application, such as we have here.

Mark