My Novatac was scaring me

[Dr.K]

I have been running rechargeables. I did a batt change last night.
Everything was working correctly, except for high.

When I switched to the high level, it came on bright for about one second, then ramped down (like when the battery is dying)

I tried 3 different cells, all with the same result. I tried some batt detect resets, a factory reset, changed some of the programming and levels, but still got this same result.

All batts tested good 3.7-3.8 volts. I was left scratching my head.

For kicks & shittles I dropped in a primary 123, and did another detect reset.

It worked fine!!

I did another batt detect reset and put in the RCR123, and now it works fine also.

Just thought I would share my quirky little adventure on new years eve.

 

[cave dave]

LiIon RCR123 generally comes off the charger at 4.1v to 4.2v.

 

[Valpo Hawkeye]

I had one do the same thing a while back. It was a one time shot. My 120p hasn't acted up in this way to this point. Time will tell. Coincidentally, I also have my levels set up so that I don't have any flicker at all. I guess chalk it up to a glitch that had to be reset. Bummer. :shrug:

 

[Dr.K]

LiIon RCR123 generally comes off the charger at 4.1v to 4.2v.

My Tenergy 900mah always come off the charger at ~3.8V

I've never had any experience with any other types

 

[iNDiGLo]

Check the Users Manual. I believe any time you change battery chemistries it requires a 'hard reset' of the light.

 

[Valpo Hawkeye]

Check the Users Manual. I believe any time you change battery chemistries it requires a 'hard reset' of the light.

No, just a battery detect, per the manual (page 10).

 

[wasBlinded]

When I check the open circuit voltage on my R123 cells after the Novatac 120P starts to dial down the top level, they are at about 3.8 volts. I'll bet that the cell could provide the current needed for 120 lumens at this point, but Novatac is being conservative about protecting them and begins the ramp down well before the cell is approaching depletion.

 

[ynggrsshppr]

Those Tenergy batteries are 3.0V lithium ions with the voltage regulation PCB right?

I think you should look into getting normal 3.7V lithium ions without protection circuitry. The Novatac might be getting confused when you use 3.0V li-ions.

 

[tebore]

I agree with the gentlemen in the above.

It's the batteries. Seems like either a really crappy charger or crappy reg circuit on the battery.

3.8v is too high for a fresh primary/ hot off the charger 3.0v li-ion. And it's too low to be a fully charged 3.6v li-ion.

It's confusing the hell out of the light. It's playing it safe and using the 3.6v li-ion profile and thinks it's low.

 

[Dr.K]

I can't wait to explain to a non-flashaholic that my batteries are confusing my flashlight.

 

[Valpo Hawkeye]

I agree with the gentlemen in the above.

It's the batteries. Seems like either a really crappy charger or crappy reg circuit on the battery.

3.8v is too high for a fresh primary/ hot off the charger 3.0v li-ion. And it's too low to be a fully charged 3.6v li-ion.

It's confusing the hell out of the light. It's playing it safe and using the 3.6v li-ion profile and thinks it's low.

It may be a voltage problem, but when one of mine exhibited this exact behavior, it was on a fresh primary cell.