AA Current draw test in D10 and RC-29

[357mag1]

Below I've listed tailcap current readings taken from the Nitecore D10 Tribute and a Romisen RC-29 II Q5 with various AA size batteries. All readings were taken with two Fluke DMMs (older 87 for current and new 77 Ver IV for voltage)

Somebody smarter on flashlights circuitry than I may know what type of regulation (if any) the RC-29 uses. It draws an amazing amount of current.

RC-29 results:

Eneloop charged 1 month ago - 2.3A at 1.25V
Eneloop fresh off charger - 2.98A at 1.35V
Rayovac 4.0 charged 1 month ago - 2.23A at 1.19V
Rayovac 4.0 fresh off charger - 2.67A at 1.3V
Nizn used several times in tooth brush and at 1.74V static - 4.2A at 1.6V
Nizn fresh off charger - 4.6A at 1.7V
Energizer Lithium fresh - 2.4A at 1.3V
Energizer Lithium 60 seconds of use - 2A at 1.25V (continues to drop off fairly fast)
Mastercell Alkaline (made in China) - 2A at 1.18V
Mastercell Alkaline after 60 seconds - 1.86A at 1.15V

D10 results:

Nizn used in RC-29 for 17 minutes - 2.2A at 1.6V
Nizn fresh off charger - 2.15A at 1.75V
Eneloop (charged in the last 12 hours) - 2.65A at 1.3V
Rayovac 4.0 (charged in the last 12 hours) - 2.99A at 1.18V
Energizer Lithium (New from different pack) - 2.9A at 1.16V
Mastercell Alkaline - 2.6A at 1.116V
14500 AW (3.7V) Unprotected - 1.05A at 3.97V
14500 AW (3.7V) Protected - 1.08A at 4V

I've seen the Energizer Lithiums last almost 3 hours at a 1A draw but they don't seem to hold up well under these higher current conditions. The Alkaline looks good but after about 3-5 minutes it is headed downhill fast. I was amazed at the Nizn current draw in the RC-29 and let it tail stand for 17 minutes while inputting this information. The light got fairly warm (like a good hand warmer) but started to cool down shortly after closed my hand around it. I wonder if the tailcap has enough resistance to lower the current draw some?

The Eneloops continue to prove their worth with the only sensible option being the Nizn (my opinion) if you want or need greater voltage.

Until I conducted this little test I had no idea these little batteries could substain this type of current output. No wonder 4 Duraloops have no problem powering my TK40s on Turbo.

I decided to take the Energizer Lithium used in the D10 test and see how long it would last in the RC-29. The way current and voltage seemed to be dropping I thought it might not last long. I have left the light on and tailstanding for over an hour now except to cut it off and measure current at 15min (2.1A) and 30min (2.1A) and 52min (2.04A) and 68min (1.89A). It is presently at 1hr 15mins and seems to be going strong. Very little loss in output. Guess them Lithiums are doing okay after all. I'm sure any Alkaline would have been long dead and the rechargeables would need a refresh charge by now.

 

[litemax]

Looks like just simple boosting based on a fixed ratio, rather than any form of regulation.

LEDS, without any resistors, will simply suck more current (Amps) are the input voltage goes up.

That is why the NiZn is supplying a lot more current than the NiMh.

 

[HKJ]

Below I've listed tailcap current readings taken from the Nitecore D10 Tribute and a Romisen RC-29 II Q5 with various AA size batteries. All readings were taken with two Fluke DMMs (older 87 for current and new 77 Ver IV for voltage)

Did you measure the current and voltage concurrently?
I.e. used this connection:

 

[357mag1]

HKJ,

Electrically I was connected exactly as you depict. I used some adapters to get the proper connections without shorting anything out. I also verified my current readings with the adapters by checking them against a standard tailcap current test (Amp meter replacing tailcap). I wanted to make sure I wasn't introducing any significant variation into the readings.

 

[HKJ]

Electrically I was connected exactly as you depict. I used some adapters to get the proper connections without shorting anything out. I also verified my current readings with the adapters by checking them against a standard tailcap current test (Amp meter replacing tailcap). I wanted to make sure I wasn't introducing any significant variation into the readings.

With two Fluke meters I suppose you have some experience in using meters .

And a note to the drawing: It is for measuring what goes into the flashlight, not what the battery deliverers. For that the voltmeter must be moved to the other side of the ammeter.
I will add this drawing (together with photos) to my DMM guide.

 

[357mag1]

And a note to the drawing: It is for measuring what goes into the flashlight, not what the battery deliverers. For that the voltmeter must be moved to the other side of the ammeter.

Either I didn't understand this comment or you have confused yourself. Your picture shows the Amp meter connected in series which will turn the light on and the Volt meter is in parallel which will read the voltage drop across the battery. It does not matter physically where the meters are as long as electrically they are connected in this fashion.

If you connect the volt meter in series you will read battery voltage but the current flow would be so little the light will not come on. If you connect the Amp meter in parallel standby as you will have just shorted out the battery.

From numerous posts of yours I have read I believe you know all of this so I'm not sure about the above comment. You are correct it would measure what goes into the flashlight which is being fed by the battery so it has to read what the battery delivers.

Need your morning coffee or am I being dense?

 

[HKJ]

Need your morning coffee or am I being dense?

I hope I can do without any morning coffee!

The ammeter might have a voltage drop of up to 1 volt, when working with a 1.2 volt battery this is rather significant. The actual drop will depend on meter and selected range, but to make my description useable with most types of meters I do it this way.
The Fluke 87 has 0.03 volt drop for each ampere, this means that with you maximum current draw of 4.6 A, you have a loss of 0.14 volt in the meter, i.e. you measured 1.7 volt, but you battery must have 1.84 volt (Without including any cable and connections losses)!

With moving the volt meter I did not mean to change between serial and parallel connection, but simply place the volt meter directly over the battery, to avoid the voltage drop in the ammeter.

I have updated the illustration to show both voltage connections:

 

[Mr Happy]

I hope I can do without any morning coffee!

I have to say I did find your first drawing a bit difficult to follow, and the second one too. For my preference, I would have shown the first drawing more like this. I think it makes it a little easier for the eye to trace where the current flows and where the voltage is measured:

That's just me. Others may feel differently of course.

 

[357mag1]

I hope I can do without any morning coffee!

I figured from all your post that I have read and enjoyed I must be missing something as you had way more than the basics down (as you prove again). I can't vouch for actual voltage drop across the 87 while taking Amp readings but that will be easy to measure. I would be surprised if it was .03 (or would have been if you hadn't stated it) but now you have my curiousity up. I will hook the 77 parallel with the 87 to read voltage.

Something to think about, I doubt the 87 when used as an Amp meter drops more voltage than the tailcap but I could be wrong. There has to be some loss through the tailcap connection as we can bet it is not a perfect conductor.

Take the Nizn battery, I doubt the tailcap can pass 4.5A without some loss and probably more significant loss than the 87. I have no experience in this area so I could be totally wrong, it is just a gut feeling.

 

[Mr Happy]

According to the manual, for the Fluke 87 on the A range the burden voltage between the terminals is 0.03 V per amp flowing, corresponding to a DC resistance of 0.03 ohms. However, this is between the meter terminals. The test leads and circuit connections can easily increase this to a higher number. If you are measuring a number of amps through any meter, expect a significant voltage drop.

 

[357mag1]

Well I tested it and voltage drop across the Amp meter and leads at a steady 3A draw was .270V for the 87 and .285V for the 77. So if Fluke's information is accurate it looks like each lead and the meter are dropping about the same voltage. Thanks HKJ and Mr. Happy for bringing that to my attention. I assumed it would be less significant.

That works out to introducing .09ohms of resistance into the circuit when taking current readings. The 3A draw light I was using above is the MKN SST-90 as it draws a very steady 3A from an IMR 26650.

I took the resistance reading of the 87 set up to read current (leads and all) and it registered .02 as did the tailcap of the MKN with the switch on. Makes me think at the higher current they would add about the same resistance to the circuit. Total assumption as one may handle higher current better than the other.

Since my original test of current draw for these two lights used the same setup it is a good indication of how each battery handles current draw and what type of voltage sag you can expect.

 

[HKJ]

Well I tested it and voltage drop across the Amp meter and leads at a steady 3A draw was .270V for the 87 and .285V for the 77.

Just be careful when using the 400mA range, there the voltage drop in the meter is up to 0.7 volt excluding cables and connections voltage drop.

I took the resistance reading of the 87 set up to read current (leads and all) and it registered .02 as did the tailcap of the MKN with the switch on. Makes me think at the higher current they would add about the same resistance to the circuit. Total assumption as one may handle higher

In my DMM guide I measure a tailcap to 0.034 ohm.

 

[Paul_in_Maryland]

RC-29 results:

Eneloop charged 1 month ago - 2.3A at 1.25V
Eneloop fresh off charger - 2.98A at 1.35V
Nizn used several times in tooth brush and at 1.74V static - 4.2A at 1.6V
Nizn fresh off charger - 4.6A at 1.7V

I didn't want to believe these high current values, but my own tests, using a Shiningbeam RC-29 II NW, align with these: 22 minutes from a NiZn, 50 minutes from an Eneloop, measured to the point when I could stare into the lens without wincing. With the NiZn, the body soon became too hot to hold.

 

[KiwiMark]

Below I've listed tailcap current readings taken from the Nitecore D10 Tribute and a Romisen RC-29 II Q5 with various AA size batteries. All readings were taken with two Fluke DMMs (older 87 for current and new 77 Ver IV for voltage)

Somebody smarter on flashlights circuitry than I may know what type of regulation (if any) the RC-29 uses. It draws an amazing amount of current.

RC-29 results:

Eneloop charged 1 month ago - 2.3A at 1.25V
Eneloop fresh off charger - 2.98A at 1.35V
Rayovac 4.0 charged 1 month ago - 2.23A at 1.19V
Rayovac 4.0 fresh off charger - 2.67A at 1.3V
Nizn used several times in tooth brush and at 1.74V static - 4.2A at 1.6V
Nizn fresh off charger - 4.6A at 1.7V
Energizer Lithium fresh - 2.4A at 1.3V
Energizer Lithium 60 seconds of use - 2A at 1.25V (continues to drop off fairly fast)
Mastercell Alkaline (made in China) - 2A at 1.18V
Mastercell Alkaline after 60 seconds - 1.86A at 1.15V

D10 results:

Nizn used in RC-29 for 17 minutes - 2.2A at 1.6V
Nizn fresh off charger - 2.15A at 1.75V
Eneloop (charged in the last 12 hours) - 2.65A at 1.3V
Rayovac 4.0 (charged in the last 12 hours) - 2.99A at 1.18V
Energizer Lithium (New from different pack) - 2.9A at 1.16V
Mastercell Alkaline - 2.6A at 1.116V
14500 AW (3.7V) Unprotected - 1.05A at 3.97V
14500 AW (3.7V) Protected - 1.08A at 4V

These values show why a light like the D10 is just better than a cheaper light like the Romisen. The RC-29 clearly isn't regulated and the D10 clearly is. With ~3.5W from an Eneloop and ~4W from a Li-ion obviously the D10 can output almost as much light from a NiMH cell as a Li-ion one - so I can feed it pretty much any available AA cell and get good performance. With the power consumption approaching 8W on the Romisen when using a 1.7V cell I don't think I'd want to use the NiZn cells in that light, it must be running WAY over spec on those.

 

[mfm]

These values show why a light like the D10 is just better than a cheaper light like the Romisen. The RC-29 clearly isn't regulated and the D10 clearly is

The original RC-29 draws less than 2A on a fully charged Eneloop from what I remember, so this is only the behavior of the "improved" driver from Shining Beam. The RC-29 II has the same Q5 LED as the RC-29 so the only way to make it brighter is by using more current.