18350 puzzling voltage readings.

Start with a freshly charged battery. Use highest mode EC11 offers. Take out the battery after 5 min. and check voltage with your DMM. As voltage gets closer to 3.9 shorten the time between readings. Stop at 3.7. Now you know how long you can run your battery on Highest mode safely. Takes very little time and effort.

My guess is runtime on Highest setting is around 10-15 min.

When using such high powered light on a tiny little battery, you have to be actively involved. You are the protection circuit.

As for the cell that got run down to bellow 1.5V, you might consider recycling it. That poor little thing got the living daylights used out of it.

Ok - Freshly charged IMR - came off the charger @ 4.2v
Rested for about 1/2 hour before putting it into EC11

DDM = 4.18v | EC11 = 4 flashes indicating 4v

All further voltages taken from the EC11. Rest periods were 15 minutes

Start - time/mode - End
β€”β€”β€”β€”β€”β€”β€”β€”β€”β€”β€”β€”β€”β€”β€”
4.0v - 1 minutes Hi - 3.9v
rest
4.0v - 1 minutes Hi - 3.8v
rest
3.9v - 2 minutes Hi - 3.8v
rest
3.9v - 3 minutes Hi - 3.7v
rest
3.7v - 2 minutes Hi - 3.5v << Battery should be removed and recharged at this point = 9 min on Hi
rest
3.6v - 2 minutes Hi - 3.5v
rest
3.5v - 2 minutes ?? - 3.5v << Now defintely dimmer than Hi
rest
3.5v - 3 minutes ?? - 3.4v << Only two modes available low and ?? (brighter than Lo)
rest
3.4v - 3 minutes ?? - 3.3v
rested for 35 minutes
3.5v - 5 minutes ? - 1.2v <<? = Was getting progressively dimmer

Removed battery DDM = 1.4v but rising fast.
By the time I got my camera out the voltage had risen to over 2.0v

Currently it is at 3.1v

The main problem as I see it is that you could go out with the battery at 3.8v then use the light in one of the mid modes for not too long a period and suddenly find your battery has been knackered. This light drains the battery too quickly for my liking :Sp

I can see on specifications, that the battery has a short runtime ; MID 160 lumens 90 minutes, high 300 lumes 45 minutes.
Is not a surprise, is clearly indicate on the manual user and on the Nitecore web.
Your IMR, how many mA? perhaps 600-700mA, if you are at 3.8V, how many mA dou think rest on your battery?, i think very few mA.
If you have read the oficial Nitecore data, I do not understand why are you surprised?

For Turbo mode.
If someone make partial runtime test…the runtime will not be the same than in a continously runtime test.
There are a step down?… if someone make partial runtime, measure voltaje, new runtime start… with more powerful, consumption will be greater than on the continuosly test.

It came off the charger at 904mAh

Have you measured on charge or on discharge?? :wink:

904mAh was the charge it accepted after the first time the EC11 blitzed it. It’s currently on charge again after its second mauling - I’ll check how much charge it takes this time :slight_smile:

You can only measured the capacity of a battery in discharge. In charge is measured the mA that the charger send to the battery (there are losses on heat and more), not the mA that will be stored by the battery.
If the charger indicate 904 mA, perhaps the battery has a capacity of 750-800 mA. Is a good battery.

Ok - thanks, I didn’t know that.

:slight_smile:
I also use this function on new chargers. It gives an idea of the capacity and quality of the battery (It is a useful approximation)

Well the EC11 is basically a pocket rocket toy IMHO. Cool toy though!

I like this Efest - after all the abuse it has had it is still accepting a good amount of charge:
.

Excellent work. How about this.

  1. dont confuse voltage with amount β€œwork” left in it.
  2. based on your observations. When you have only two modes left you should recharge if possible. If not possible expect only a few minutes left.

problem solved.

It also seemes/seemed that the brightness dimms noticably much earlier, if you need the brightness then charge then, if not run on a lower setting and get increased runtime.

no extra equipment needed, the light tells you when it need a new battery (or recharge)

The only down side I see for this cool toy would be that the light doesn’t flash when getting down to say 3.0v. Well, and also the the PWM. Anyways, you got to expect the short run times with a 18350 pushing 900 lumens. That’s quite a load on a tiny batt.

As I said, I don’t like boost drivers with lithium ion batteries, as that is potentially more dangerous than a regulating driver that can’t drain the cell so much. On the other hand, I have read that IMR cells are not as dangerous as ICR cells.

Nothing wrong with boost drivers, if they actually add low voltage protection! Without it you have a piece of junk, no excuse for the lack of low voltage protection imo. Yes, its harder to implement in a light that also takes CR123A.

It would have to remember what type cell is in it, as a discharged lithium ion cell might have the same voltage as a CR123a. Even so, if you took the discharged lithium ion cell out and put it back in, the light would think it was a CR123a and run it down to 1.5 V. The only safe way would seem to be a user operated switch.

Do you mean β€œHigh” or β€œTurbo”? I am hoping those numbers are on TURBO[MAX] not HIGH!

As you can see you ONLY got 9 minutes on HIGH[?] W/ a resting voltage of 3.50v. I got 12 combined minutes on TURBO w/ a resting voltage of 3.50V. I got 3 more minutes than you!

I see you are using the Efest IMR 18350 800mah. I believe their MAX CONTINUOUS DISCHARGE CURRENT is ~ 6=A. Mine is 10.4A and has 100 less mAh yet it went 3 minutes longer than yours??!

BATTERY: EFEST IMR β€œPURPLE” 18350 700 mAh.

TURBO OUTPUT -I DID 3 MINUTE INCREMENTS[THAT IS THE STEP DOWN] W/ ABOUT 4 MINUTES OF REST IN BETWEEN.

TAIL STAND/NO FAN/LOFT TEMP. WAS 74F/23.3C.

STARTING VOLTAGE:4.20V* I actually used my stop watch on my phone app! STEP DOWN WAS EXACTLY 3 MIN. 7.7 SEC.!!!

3 MIN= 3.90V 6 MIN=3.74V
9 MIN=3.64V 12 MIN=3.50V

I decided to try for 3 more minutes. After an additional 2 min. 10 sec. the light stepped down to medium or low! I immediately checked w/ the DMM and it was @ 2.28v!! Needless to say when I tested my second Efest IMR 18350 I stopped at 12 minutes. Both batteries tested exactly the same.

The EFEST IMR 16340 RAN FOR 15 MINUTES[3 MIN. INCREMENTS] AND WAS @ 3.50V .It did not get as hot and certainly did not push the light quite as hard.

Yes - sorry I should have said Turbo and not Hi.

Due to your results being given to two decimal places (e.g 3.64v) I assume you were removing the battery and using a DDM to take the voltage readings.

Apart from the initial DDM reading of 4.18v before putting the battery in the light all other of my voltage readings were taken by loosening & tightening the EC11’s tail cap and counting the number of flashes. It is supposed to be accurate to within 0.1v but I think it could be worse than that especially at higher voltages as my initial DDM reading of 4.18v was contradicted with a reading of 4.0v (4 flashes) by the EC11 just seconds later. This would indicate an error of nearly 0.2v by the EC11.

I also took the post run readings immediately after each run so there was no rest period for the battery as there would have been if I had removed the battery after a run to measure it on my DDM.

If you look at my readings again you will see that the EC11 was still indicating 3.5v after a total of 13 minutes run time - so, taking into account the inaccuracy of the EC11 and the difference in runtimes and measurement method I think our results could be very close.

When I get a chance I’ll rerun the test using a DDM using the same runtime and rest periods as you did - how long after each run did you measure the voltage?

The brightness levels make more sense with a CR123 (very low 1 lumen, low 40 lumens) and the boost driver without battery protection also makes sense for that.

They built it for IMR 18350 for the 900 lumens boasting factor.

It takes a protected 16340 so I now use that or a primary CR123 unless I'm planning to show off.

Now all I need i small case to carry an 18350 in my pocket.