DX protected "C" cells in the FM 2xC lights

[cernobila]

Well finally got two of these cells to try out in my 2xC Prince.

http://www.dealextreme.com/details.dx/sku.26799

Charged them on my Pila IBC charger, they measured 4.14 and 4.16. Was impatient and did not top them up any higher. They fit the same as the AW black C cells.......started with the WA1111 rated at about 3.8A.......when cold, fires up on the second push on the button, when warm, turns on with first push.

Now, when used with the WA1160, (4.3A ?) it took about three pushes on the button before turning on, again when warm came on with first push.....After playing around focusing the 1160 and turning it on/off, the bulb gave up, (one side of the element melted) lucky that I have another three.

I don't have three of these cells so I could not test the WA1185, (3.4A) perhaps with a bit of luck, this one may start up on the first push on the switch.

In the meantime, I am quite happy with these cells in combination with the WA1111 bulb in the Prince and will continue using them in this light.

Perhaps somebody with the equipment and know how could test these and compare them to other C cells.

 

[lolzertank]

Re: DX protected "C" cells in the FM 2xC Prince

Is it possible to shoehorn a soft start in? A cold filament is essentially a short circuit and its current draw is probably quite a bit higher than the protection circuit's threshold.

It's awesome that DX finally has protected C cells with functioning protection circuits. Not to mention at a measly $10 too. (Remember how much AW's C cells cost? )

 

[cernobila]

Re: DX protected "C" cells in the FM 2xC Prince

Is it possible to shoehorn a soft start in? A cold filament is essentially a short circuit and its current draw is probably quite a bit higher than the protection circuit's threshold.

It's awesome that DX finally has protected C cells with functioning protection circuits. Not to mention at a measly $10 too. (Remember how much AW's C cells cost? )

Agree about the price, less than half of the black AW's. I have been using the Prince quite a bit last night with the WA1111 and gotten used to doing a fast double push (just like a double tap in pistol shooting) and it now feels like a "no issue".......No idea about the soft start addition in the Prince switch, maybe "fivemega" could let us know. More importantly, having used soft start switches in many of my other lights, I prefer not to have them in lights that need to be used on/off quickly. I may get another three cells and try them in my 3xC BigLeef with a KT head and a WA1185 bulb, should work just as well.

 

[DM51]

Re: DX protected "C" cells in the FM 2xC Prince

It sounds as if the high current protection is set too low on these cells for their size - the circuits are probably the same ones used on much smaller-capacity cells. I don't know whether this might lead to other problems.

It would be interesting to see a charge-discharge analysis, to see what their true capacity is.

 

[Patriot]

Re: DX protected "C" cells in the FM 2xC Prince

Do you have anyone in your area that can test exactly where the current protection kicks in, maybe an electronics store? I'm asking because perhaps just one cell is acting up vs. both of them.

 

[LuxLuthor]

Re: DX protected "C" cells in the FM 2xC Prince

Do we know the specs on the PCB? I got some, and may run some discharge tests on them. One of them had a 40% charge, and setting my Hyperion to charge it at 2A it went up to 2A before switching to CV mode.

I can try to discharge at 7A and lower it until I see where the PTC no longer kicks in.

 

[cernobila]

Re: DX protected "C" cells in the FM 2xC Prince

Do you have anyone in your area that can test exactly where the current protection kicks in, maybe an electronics store? I'm asking because perhaps just one cell is acting up vs. both of them.

I don't know anybody that I could go to, I do know that the protection isn't as bad on these as it is on my KD protected D cells in my Maglite. If I can run lamps/bulbs up to and including 3.4A - 3.8A using a regular switch on my FM and BigLeef "C" lights, I will be very happy. The main advantage is that these DX cells are the same size as the black AW cells and fit in the same flashlights without magnets or anything else......These are not perfect but so far are the best option to the AW black cells.

 

[cernobila]

Re: DX protected "C" cells in the FM 2xC Prince

Update....

Tried the DX cells in a 2xC FM original body/switch with a KT turbo head and LF IMR M3T lamp. (3.4A) Again when warm, it comes on with first push on the switch. I tried a few short burst and let the light lie down on its side in room temperature of 19 degrees C or 66 degrees F. If I use the light every 10 - 15 seconds, it starts up on single push, if I leave it longer then it needs the double tap.

With a SF MN 16 lamp, (about 2.7A) the light comes on with the first push every time without fail.

Looking forward to LuxLuthor's test results on these cells.

 

[LuxLuthor]

Well, I am reminded of the addage: "You get what you pay for." I will confirm this with a 2nd cell that is charging, but after a full charge on my Hyperion 1210i, the starting voltage was 4.18V when placed into a secure clamp with thick wire soldered to contacts & going to CBA-II.

I first ran a 5A discharge, and it ran all the way down to 2.4V where I set my end of test trigger. No low voltage protection kicked in. Following this test, the voltage rebounded up to 3.32V in 30 sec, and 3.41 in 1 min. It registered 2,731 mAh output. Edit: It only got lukewarm to the touch, which is good.

I then took a 2nd cell that was about 94% charged, just to find the protection current cutoff. I ran it at 8A, and after 30 mAh, protection broke circuit. I then ran same cell at 7A, and after seeing no protection after about 200mAh, I stopped test. Same with 7.5A

So on this one cell, apparently the low voltage protection is below 2.4V, or requires a longer period at low voltage to trigger protection. Apparently the high current protection is somewhere between 7.5A and 8A of discharge. The curve shows an output that I can best sum up as "better than nothing."

​

 

[cernobila]

Well Lux, that is disappointing.......looks like back to square one. I will keep using the two that I have and follow their performance. If I don't like what I see when charging/discharging, I will toss them. (in a safe way )

 

[The Dane]

@ cernobila

Got some nonprotected DX C-cells and I'll trade You for Your protected ones.
Interested?

 

[The Dane]

As Lux said, 8A is the limit:

Same charger and tester!

 

[LuxLuthor]

As Lux said, 8A is the limit:

Same charger and tester!

You also had tight clamp holder to give best surfare area for testing? I ask because your protection shutoff at 8A looks to be at 50+ mA output.

For comparison, other PCB's shutoff within 1-2 seconds when high discharge is used....so I'm not even confident on the quality of the PCB they are using.

I have images of Mama-san toiling over a big iron vat of lithium cobalt stirring it with a big wooden paddle over a wood fire and scooping out small ladels of the finished electrolyte mixture into small metal C cell size cups. The children jump from their rice bowl feast and begin inserting a conductive dipstick in the lid and smacking it with a hammer to seal it.

Then they move down to Chen who slaps an acme PCB on the ends. They only have one brand of PCB no matter what cell they are working on. Next, Hua rolls a piece of blue plastic around it. Jing only has a stamping machine used on D cells, so he stamps cells with erroneous 5500mAh rating, not knowing what the numbers mean, and what difference could it make anyway. Quon takes a full bag of loose "completed" cells over to Ming-Lu who bicycles a mile to her local gradeschool. She delivers them down to the basement where DX operates their internet/shipping operation.

 

[cernobila]

@ cernobila

Got some nonprotected DX C-cells and I'll trade You for Your protected ones.
Interested?

Sorry but I am a "run time", "protected" type of a person and I don't use unprotected cells by choice......too lazy to do all the checks with them. So my holy grail is a good quality protected large capacity "C" cell......I will not give up.....I will climb the highest mountain, cross the widest river.....even give up some of my last vices to find a good C cell......Its a curse I tell you, a curse.

 

[The Dane]

The tips are @ 14 sq mm brass

Springtension @ 2kg

So connections are pretty much ok.

 

[LuxLuthor]

Yeah, the extra bolt, eyelet is likely enough to explain the slight difference. I remember talking to Mike at CheapBatteryPack who said his ideal setup is to solder 14AWG lead direct from tester to end of battery itself. Obviously that can't be safely done (IMHO) with Li-Ion cells, but the fewer connection surfaces the lower the resistance.

 

[The Dane]

Point taken, mods made:

 

[LuxLuthor]

That's as good as you are going to get. I have a similar setup. 14AWG soldered to the D cell size end caps I use to make battery packs, then epoxy glued yellow clamp pads to Nickel end cap. When I tighten contacts together, I measured 11 mΩ which is close enough for government work.

​

 

[DHart]

Just received my pair of these cells... only using them to drive a Malkoff M60 Q5 lamp in a Fivemega 2xC body... draw is only 550 mA!

Both cells arrived charged at 4.12. Good fit in the light. No idea on effectiveness of the protection circuit... but at least I can now use this flashlight for the first time. :shrug:

 

[Kestrel]

Just received my pair of these cells... only using them to drive a Malkoff M60 Q5 lamp in a Fivemega 2xC body... draw is only 55 mA!

Hmm, 55mA, isn't that way too low??
Edit: OK, you posted 550 mA in another thread. Never mind.