18350 puzzling voltage readings.

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logindetails
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18350 puzzling voltage readings.

The battery (Efest 18350 IMR 800mAh) in my EC11 ran out of juice so I reinserted it to check how many flashes the EC11 gave to indicate the voltage it had quit at and was a bit shocked to see one flash a pause then five more flashes indicating 1.5v !!!
I immediately took the battery out and tested it on my DDM which showed 1.55v
A few seconds later it showed 1.57v so the voltage was rising.
Testing the battery some hours later showed 3.09v which it appears to have settled at.

How does the voltage rise by itself? Should I be worried about the 1.55v reading?

keengeorge
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logindetails wrote:

The battery (Efest 18350 IMR 800mAh) in my EC11 ran out of juice so I reinserted it to check how many flashes the EC11 gave to indicate the voltage it had quit at and was a bit shocked to see one flash a pause then five more flashes indicating 1.5v !!!
I immediately took the battery out and tested it on my DDM which showed 1.55v
A few seconds later it showed 1.57v so the voltage was rising.
Testing the battery some hours later showed 3.09v which it appears to have settled at.

How does the voltage rise by itself? Should I be worried about the 1.55v reading?

Good Day logindetails, Smile

 

Yes, you should be concerned about a battery voltage of 1.5/1.55V as most likely you have damaged it and thus shortened its lifetime.

Make sure that you monitor this battery carefully from now on (you should monitor all your batteries).

 

You should Never drive an Efest 18350 IMR below about 3.0V, & preferably not below 3.5V for longer service life (this also applies to all Lithium rechargeable batteries).

 

Voltage of Lithium based rechargeable batteries rises when you rest them after use due to their chemistry.

 

Best Regards,

George

 

logindetails
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Thanks for the advice George but what I’m wondering is what the real voltage of the battery was when the light died? Should I consider it to be the 1.55v measured immediately after removing the battery or the 3.09v measured some hours later? Also, how did the measured voltage increase?

ruffles
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Any chance your multimeter battery is low and should be replaced? Low batteries and flaky readings seem to go together sometimes.


 

Fritz t. Cat
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It might even be dangerous to continue over-discharging this or other lithium ion batteries.
You know, there is no water in them to put out fires that might start in the other chemicals.

It would be safer to use lower voltage batteries in this flashlight, then buy an inexpensive light specialized for lithium ion cells.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

Fritz t. Cat
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ruffles wrote:
Any chance your multimeter battery is low and should be replaced? Low batteries and flaky readings seem to go together sometimes.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

keengeorge
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logindetails wrote:
Thanks for the advice George but what I'm wondering is what the real voltage of the battery was when the light died? Should I consider it to be the 1.55v measured immediately after removing the battery or the 3.09v measured some hours later? Also, how did the measured voltage increase?

Good Day logindetails, Smile

 

Both the EC11 & DMM (& all voltmeters) measure voltage using a VERY Small current load (they have a very high resistance).

The voltage of your battery UNDER LOAD WAS LOWER than the 1.5 or 1.55V measured by both the EC11 & DMM afterwards (under NO load).

 

Whenever you put a load on a battery (draw current from it), its voltage drops (known as Voltage sag).

So when you used your EC11 as you mentioned, the voltage of the battery would have reached lower than the afterwards measured 1.5/1.55V (under NO load).

 

The readings are consistent with each other, thus the DMM's reading seems OK.

But you should regularly check the DMM's battery (say at least twice a year).

 

And as I said earlier:

Voltage of Lithium based rechargeable batteries rises when you rest them (ie: under no load) after use, due to their chemistry.

 

Best Regards,

George

 

 

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smaller lights wrote:
if these imr batteries don't have discharge protection, how do you know when they need to be charged ? the EC11 has a low voltage indicator, as i recall. ( i have one coming in the mail ) but does the EC11 shut off by itself or flash like the supbeam M6 ??

what is the lowest safe voltage for an IMR battery. i have several IMR 26650s by MKNE

Good Day smaller lights, Smile

 

I have not yet seen or heard of any good/decent/genuine Protected IMR batteries, so they do NOT have low voltage or high voltage protection.

The problem seems to be getting/sourcing protection circuits that can handle the high current.

Thus you MUST check their voltage VERY OFTEN with a Voltmeter/Multimeter or DMM.

 

Lowest recommended voltage for IMR batteries is 3.0V.

 

Best Regards,

George

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George – From what you are saying and I do not doubt you are correct, it would seem that the Nitecore EC11 is a very dangerous light to use!
The run times of the light are not that good and the first sign I had that the battery was running out of juice was when I switched to a higher mode and there was no change in brightness. If I remember correctly, after clicking the mode switch a few times the main light switched itself off and the red led started flashing – it was at that point I loosened & tightened the tail cap to measure the voltage = 1.5v
Removing the battery and testing it on my DDM confirmed a very low voltage = 1.55v
My worry with this light is that if it is allowing the battery to drop to such a low voltage under load – and with a Hi of 900+ lumens there would be a lot of load – but the battery recovers to an acceptable voltage after a short rest, then you could be duped into thinking all is well – especially if you only test a battery before use not immediately after.
The battery itself appears no worse for wear and accepted an indicated 904mAh of charge on my Opus charger.

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logindetails wrote:
George – From what you are saying and I do not doubt you are correct, it would seem that the Nitecore EC11 is a very dangerous light to use!

EC11 like other many lights have not cut off , for example, the great Jetbeam RRT01… is your responsability; use battery with protection or if you use IMR check the voltage. EC11 is great, you can check the voltage with the flashlight, when is about 3.5V you must charge.

logindetails
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Trevi_lux wrote:
logindetails wrote:
George – From what you are saying and I do not doubt you are correct, it would seem that the Nitecore EC11 is a very dangerous light to use!

EC11 like other many lights have not cut off , for example, the great Jetbeam RRT01… is your responsability; use battery with protection or if you use IMR check the voltage. EC11 is great, you can check the voltage with the flashlight, when is about 3.5V you must charge.


Trevi – just so you know, Nitecore recommends the use of IMR batteries in the EC11 and they don’t come with protection.
It is the rate at which the EC11 discharges the battery that makes it dangerous and it’s very impractical to switch off and test the voltage every minute or so.
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It seems as a major designflaw that the light doesnt shut off by itself at <3V in my opinion. Otherwise it´s a damn nice light!

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Ormbett wrote:
It seems as a major designflaw that the light doesnt shut off by itself at
I agree.
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The EC11 uses a boost converter, that is the reason it can drain LiIon batteries very low.

The revealing specification is that is supports CR123 batteries, a single CR123 cannot drive a led at decent brightness without a boost converter!

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

logindetails
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HKJ wrote:

The EC11 uses a boost converter, that is the reason it can drain LiIon batteries very low.

The revealing specification is that is supports CR123 batteries, a single CR123 cannot drive a led at decent brightness without a boost converter!


So is the EC11 basicall a battery killer – at least as far as LiIon’s are concerned?
I’d love to see a review of this light by someone who can test the drain on the batteries properly to either put my mind at rest or confirm my fears.
In the meantime, I’m going to fully charge a battery then run the EC11 on high for one minute intervals and check the voltage immediately after each run.
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logindetails wrote:
HKJ wrote:

The EC11 uses a boost converter, that is the reason it can drain LiIon batteries very low.

The revealing specification is that is supports CR123 batteries, a single CR123 cannot drive a led at decent brightness without a boost converter!

So is the EC11 basicall a battery killer – at least as far as LiIon’s are concerned? I’d love to see a review of this light by someone who can test the drain on the batteries properly to either put my mind at rest or confirm my fears. In the meantime, I’m going to fully charge a battery then run the EC11 on high for one minute intervals and check the voltage immediately after each run.

I use my EA11 with IMR, and have not cut off, I know the risks and the use of Lithium. Not problem for me, perhaps some people don’t know about use of Lithium batterys, not a toy..

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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.

logindetails
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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
———————————————
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

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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?

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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.

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Trevi_lux wrote:
…Your IMR, how many mA? perhaps 600-700mA, …..

It came off the charger at 904mAh
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Have you measured on charge or on discharge?? Wink

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Trevi_lux wrote:
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 Smile
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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.

logindetails
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Trevi_lux wrote:
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.
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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)
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Well the EC11 is basically a pocket rocket toy IMHO. Cool toy though!

Hey Babe, check out my new light!!

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

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logindetails wrote:
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
———————————————
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

Excellent work. How about this.

  1. dont confuse voltage with amount “work” 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)

(“It’s good that most people can’t remember their previous lives. Otherwise
things would be a lot more complicated than they already are.”
Ajaan Lee Dhammadharo)

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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.

Hey Babe, check out my new light!!

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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.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

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