Novatac VS EDC low voltage operation

[Derek Dean]

Ok.

I started it again.

Did a battery reset.

Brand new cell installed.

Will soon see what happens.

*** data below ***

start 2:12 p.m.

I'll look forward to the results. I too noticed a bit of strobing on the lowest 2 levels with a partially used Battery Station RCR123, which was odd, because the top levels still worked fine. I took out the cell, let the light sit for 10 minutes, put in a freshly charged one, and it seems fine now.

However, I think it's worth a bit more investigation to find out if this is problem that needs be addressed. I'm going to do some more testing tomorrow. I'm hoping that was a one time event.

 

[turbodog]

No. I want my NovaTac to have steady output on a partially depleted cell. Regarding the tint, yep - my NovaTac has perfect tint.

But, to be fair to hds and all older lights, tint is not much of an issue anymore. The new emitters have extremely good tint.

 

[paxxus]

Just ran down a cell until it stepped down to a quite low level. As usual there was some continuous pulsing involved, depending on level. I then popped out the cell and put into my old HDS and it ran for an additional 5 mins on a quite high level, then the HDS stepped down to a quite low level. Then I put back the cell in the NovaTac and it just stepped down and shut off. So yeah, it could indeed appear that the NovaTac has a less effective power supply (in addition to the pulsing).

I have now put that cell back in the HDS and it runs fine on a low level.

 

[AZLight]

Just ran down a cell until it stepped down to a quite low level. As usual there was some continuous pulsing involved, depending on level. I then popped out the cell and put into my old HDS and it ran for an additional 5 mins on a quite high level, then the HDS stepped down to a quite low level. Then I put back the cell in the NovaTac and it just stepped down and shut off. So yeah, it could indeed appear that the NovaTac has a less effective power supply (in addition to the pulsing).

I have now put that cell back in the HDS and it runs fine on a low level.

Have you considered that it might be the LED that is causing the pulsing and not the power supply? Your experiment is based on your perception of the light output and not that of a measured lumens vs input current and voltage. The only way to tell is to swap the LED in the HDS into the Novatac. Until then, every thing is a guessing game.

 

[paxxus]

Have you considered that it might be the LED that is causing the pulsing and not the power supply? Your experiment is based on your perception of the light output and not that of a measured lumens vs input current and voltage. The only way to tell is to swap the LED in the HDS into the Novatac. Until then, every thing is a guessing game.

The light output from the NovaTac is easy to perceive as it simply shuts off, while the HDS can produce a decent amount of light from the same cell. The HDS is by the way still running on a low level on that cell (more than 30min after the NovaTac gave up on that cell), and when I say "low" level it is still significantly brighter than the lowest setting on the NovaTac, so it's not just because the HDS can go lower than the NovaTac.

I see these experiments more as a testament to how well designed the old HDS actually was. It's amazing. The NovaTac is still a very fine light - I EDC it instead of the HDS.

 

[AZLight]

The light output from the NovaTac is easy to perceive as it simply shuts off, while the HDS can produce a decent amount of light from the same cell. The HDS is by the way still running on a low level on that cell (more than 30min after the NovaTac gave up on that cell), and when I say "low" level it is still significantly brighter than the lowest setting on the NovaTac, so it's not just because the HDS can go lower than the NovaTac.

I see these experiments more as a testament to how well designed the old HDS actually was. It's amazing. The NovaTac is still a very fine light - I EDC it instead of the HDS.

You need to look at the spec sheets for both LEDs to see that for the same input V & I that the Seoul LED might not light up or it might flicker. You are comparing apples and oranges since the two LEDs have different performance characteristics. A similar situation is when your car battery is drained. The dome light might still be brightly lit but the headlight is a no go.

The HDS is a fine design and I still carry them on the job along with the Novatac. But, your experiments does not mean a whole lot without empirical data, especially at such a low VI regulated input.

 

[paxxus]

You need to look at the spec sheets for both LEDs to see that for the same input V & I that the Seoul LED might not light up or it might flicker. You are comparing apples and oranges since the two LEDs have different performance characteristics. A similar situation is when your car battery is drained. The dome light might still be brightly lit but the headlight is a no go.

The HDS is a fine design and I still carry them on the job along with the Novatac. But, your experiments does not mean a whole lot without empirical data, especially at such a low VI regulated input.

You are right of course, this is by no means a scientific experiment - just some quick observations from my side. My HDS is modded with a Seoul by the way, but still, the Vf could differ giving the HDS an advantage.

 

[TITAN1833]

It seems we have been hood winked by Novatac!

Perhaps they have shares in duracell? buy more batteries.

I am not happy about this,I thought,this light would even sacrifice rechargable protected batt,to get some light and not leave you in the dark? hmmHave I missed something?

 

[Derek Dean]

It seems we have been hood winked by Novatac!

Perhaps they have shares in duracell? buy more batteries.

I am not happy about this,I thought,this light would even sacrifice rechargable protected batt,to get some light and not leave you in the dark? hmmHave I missed something?

Well, I wouldn't get overly upset about this just yet. I know I'm not. BTW, I believe that NovaTac was talking about sacrificing unprotected RCR123 cells, as the protected cells will kick off from their own internal protection circuit, independently of the NovaTac's circuitry.

It's still early in the game for the NovaTac EDC series, and we are still finding things out about it. Further testing should help clarify any issues regarding low battery handling capability.

As it is, I'm using a protected RCR123 cell in my 120P because I feel a bit better with the extra added safety of the protection circuit, both for use and for charging. I change out the cell frequently for a newly charged one, as I like leaving the house with a full, or nearly full cell. Also, my initial tests showed that the light begins lowering the levels before the cell's protection circuit kicks in, so I haven't been left in the dark yet, although like any good CPF member I have my trusty backup 1xAA in the other pocket 'just in case', along with a coin cell keychain light.

 

[turbodog]

I have returned from errands and found the novatac OFF.

I turns back on and seems to run at the primary level. This is not right... it should still be running, but at a lower level.

 

[turbodog]

Ok.

It's off again.

I just turned it back on.

 

[Derek Dean]

I decided to do a full runtime test so that I would know exactly what I can expect when using a protected rechargeable RCR123 cell and running the NovaTac 120P at Max output:

NovaTac 120P set to use a rechargeable 3.7 volt cell per NovaTac instructions. Using a fully charged (and reasonably new, maybe 8 charging cycles) Battery Station 900 mAh RCR123 cell that had been sitting in a 65 degree room for about 4 days. Battery reads 4.2 volts to start the test (using a very old, but reliable Radio Shack analog 'Micronta' mulit-tester).

I'm using a Luna-Pro SBC analog light meter with a fresh 9 volt battery to continually check the light level during the test. The light is sitting on the table facing the meter which is 1 foot away. Ambient temperature is 58 degrees. Times are accurate to within 15 seconds either way.

My lumens numbers were not actual readings. I used NovaTac's published rating of 120 lumens for the top level, and after observing and measuring very precise 1 stop drops each time the light level dropped (which equates to a halving of the light output), I believe the numbers to be at least representative of what I can expect.

12:10 am.........begin test with light set to highest level.......... 120.0 lumens
12:40..............1st drop...-1 stop on light meter...................... 60.0
12:42..............2nd drop..-1 stop.......................................... 30.0
12:43..............3rd drop..-1 stop.......................................... 15.0
12:44..............4th drop..-1 stop............................................ 7.5
12:45..............5th drop..-1 stop............................................ 3.8
12:47..............6th drop..-1 stop............................................ 1.9
12:52..............7th drop..-1 stop............................................ 0.94
12:53..............8th drop..-1 stop............................................ 0.47
12:57..............9th drop..-1 stop............................................ 0.23
1:00..............10th drop..-1 stop............................................ 0.12
1.01..............11th drop..light begins low battery warning pulse.. 0.08
1.10 am........ test terminated. Turned off light, turned back on and set to lowest level (.08), light began low battery warning within 10 seconds, and kept going. Turned light off. Battery tested at 3.2 volts.

Other observations: I kept close tabs on the light meter and noticed very little fluctuation of the needle during the 1st 30 minutes of the test, very flat and even. The meter was also flat between level drops, with no visible fluctuations observed, except at the very, very end of the test. What happens when the light goes into low battery warning mode is that it is mostly on, with a slight off/on every second of so.

After the light had been in the low battery warning mode for 7-8 minutes, I did observe a very slight, uneven, but not terribly prominent flicker in the LED. After one minute of that I terminated the test.

Comments: I'm not sure exactly how to interpret the results, as I've not had that much experience with this type of thing. Maybe turbodog would be willing to offer some insight into whether these readings have any relevance to the discussion at hand.

Of course, this test applies only to how the light handles rechargeable cells, so I think I need to do a similar test using a primary cell to see exactly how much juice my light will suck out of one of those, and what happens with the regulation when the primary begins to become depleted.

Personally, I was pretty happy with the fact that I got another 20 minutes of useable, dimming but still regulated light after my initial 30 minutes of excellently regulated pedal-to-the-metal full output, and that the light dropped the output levels before the battery's protection circuit kicked in, so that I never did have the light actually shut off completely. I like that. It was also cool that even the low battery warning, which seemed like it would go for a while (for sure the 9 minutes I observed), would still be quite usable if absolutely necessary.

BTW, I know the internal battery protection circuit of this particular battery is functional as it has worked in another light.

As to the slight bit of flickering I noticed after 7-8 minutes of the low battery warning.... since NovaTac suggests that the battery should be changed well before encountering the low battery warning, I feel the light performed well within it's designated parameters, and although I would rather have not had that occur, I can certainly live with it as an acceptable quirk.

Maybe someone with more experience can tell me how this compares with what the HDS did in this situation. Does 3.2 volts seem too high a point for the light to be going into the battery warning for a rechargeable? It might be nice if there were a menu included in the options section to let us select different values for the low voltage warning. Let me know what you think.

 

[shawn a.]

Hi there, another country being heard from here.
I put all 6 of my novatac 120Ps, and my 2 hds U60XRGTs on with primary cells from Battery sta. Put them on at the closest power level I could get, and let them go out. (the level I chose was the primary level on the novatacs, and the secondary on the HDSs ((because the novas come on at the lower of the 2 toggle settings, and the HDSs come on at the higher of the 2 toggle settings)) Make sense?-anyway they all were running the next morning 12 hours later. When I next checked them,after about another 5 or 7 hours later, all the novas were out except one, which I noticed was a bit dimmer than the other novas right at the start. This last nova lasted a total of 25 hours, and the HDSs lasted for about 48 hours for one of them and over 96 hours for the other, with appropriately dimmed output, of course. When the last HDS went out, it was at the lowest setting posssible, according to the other one (which I had put a new battery in) when put on the lowest setting. (I hope I presented this clearly)
Anyway, all that is the reason I'm offering to trade 120s for u60XRGTs in the Marketplace section.
My computer is on hash, so I can only reply from the local library. (Yes, I live in a cave in the hills-with dial-up when it works)
Thanks for listening,
Shawn

 

[AZLight]

.... HDSs lasted for about 48 hours for one of them and over 96 hours for the other, with appropriately dimmed output, of course. When the last HDS went out, it was at the lowest setting posssible, according to the other one (which I had put a new battery in) when put on the lowest setting. (I hope I presented this clearly)
Anyway, all that is the reason I'm offering to trade 120s for u60XRGTs in the Marketplace section.

So you would like to trade the Novatac with predictable performance for some thing more unpredictable like the HDS? A 48 hours span is a very wide margin of error. You are not asking for a fair trade either. A no longer availabe and rare u60XRGT that cost almost twice the Novatac when new is not what you are going to get, may be a B42.

 

[shawn a.]

So you would like to trade the Novatac with predictable performance for some thing more unpredictable like the HDS? A 48 hours span is a very wide margin of error. You are not asking for a fair trade either. A no longer availabe and rare u60XRGT that cost almost twice the Novatac when new is not what you are going to get, may be a B42.

Hi AZLight,
I see it the other way around, the nova is the unpredictable one ,while the hds just reduces its light for a much, much longer time and more "gracefully" The hds uses more of the battery's power. I can use the "used" nova cells in the hds for about 24 more hours, on average. Of course the light level is much lower, but it is very usable.
Fair trade? Hey, if you have a used u60xrgt, I'll throw in some cash and the nova 120p!
How's that?
Shawn A.