High Drain with LR vs Regular batts with regular attys?

[tinstar15]

I'll put this question out there for folks using mods with these setups.....

If you have a fixed 3.7v mod that takes high drain batteries and also accepts regular non-high drain type batteries, do you notice a difference in performance between the LR and regular resistance (RR) attys?

I found that (for me) if I use a RR atty with my regular batteries, the performance is fine. If I use high drains with an RR atty, the performance is somewhat mediocre.

If I use regular batteries with a LR atty, the performance is fine but drops off after around half of the batteries useful range of time (about 1 hr with 10440s, about 3 hrs with 14500s and 18350s).

If I use high drain batts with LR attys, the performance is generally steady for the full time, but not quite as strong as it was for the fresh reg batts.

I use Boge, Joye, and SLB for the LR attys and the same makes in RR.

For the mods I'm using:
1. SD MKII with high drain 18350 from Nhaler and regular 18350s from TW.
2. Super T P10 with high drain 10440s from Nhaler and regular 10440s from Joye (old stock 320mah and newer 360mahs)
3. Puresmoker ICON V1.1 with regular Tenergy 14500s and High Drain 14500s from PS.

As a side note, the 320mah Joye 10440s seem to perform noticably better than the newer 360mah Joye batteries.

One factor/theory that I'm tinkering with is that performance may be different in mods that are not of the "mechanical" variety.

Anyone with any insights or observations, please post them.

Thanks

Tinstar

 

[revolver]

I have found similarities...
Should ask Scottbee...
He's da man!

 

[mdocod]

Initial state of charge of an ICR cell is commonly higher than IMR cells. As high as 4.25V as apposed to ~4.15V. While an IMR cell may charge to 4.20V or higher, the actual state of charge is rarely that high. The maximum state of charge for an IMR cell is reached when all of the ions have been moved to the anode. With ICR cells, even when at "full" charge (~4.20V), the balance of ions from the anode to cathode is around 50%, which means that the potential can be often pushed further. (Do not exceed 4.25V unless manufacture data sheet allows!).

See the following link:
Battery Performance Characteristics - How to specify and test a battery

Scroll down to the section about cell impedance.

As I understand, IMR cells probably have lower Rm and Ra, but higher non-linear Ri. The result is that IMR chemistry has an inherent voltage sag required to "get things chemically moving" that is higher than ICR. The effective resistance of all of those components can be very similar to ICR cells at low loads. Combine the lower starting voltage of the IMR cell with more voltage drop required to excite the cell chemically (higher Ri), and IMR will often not perform as well at lower loads.

As a general rule of thumb, based on the rough numbers I have played around with... For small cells, like sub-17500 size, IMR is the preferred choice for almost all ecig loads because of the safety issue of operating ICR cells above 2C loads. In some comparisons, the ICR cell may perform slightly better (especially when the cells are new), but the trade-off in cycle life and safety is likely not worth it. Also, in smaller sizes, like 14500/16340 and smaller, IMR cells seem to compete very well for true capacity against ICR cells.

Once cell sizes like 18650 are considered, there is no advantage to an IMR cell within the scope of most ecig atty loads. The ICRs higher effective starting voltage combined with dramatically higher capacity (~double) and similar effective operating resistance at these low loads (low for this cell size) will result in a far better user experience.

Eric

 

[Papa Lazarou]

You'd need to check the voltage under load to see what's really going on. Adapters to allow you to connect a multimeter should be easy enough to make and it would be nice if someone sold them. In 18650 size, I can't say I've noticed a difference between a freshly charged TrustFire battery and an IMR 18650, on any atomiser. I find the IMR's seem to hold up better as they discharge, particularly with low resistance atty's. They seem to work well until they stop - at which point they are almost completely discharged. I know it's not good to fully discharge them and they are unprotected (thought I killed one originally, although it seems fine) so I tend to be on the lookout for any drop in performance with the high drains and throw it on the charger before it gets to that state. On the other hand I've never fully discharged the ICR types, as they seem to get pretty weak well before the protection circuit cuts in (usually measure about 3.7-3.8v unloaded voltage by the time I switch them over).