Ultrafire Protected RCR123 880mah & DSD Charger my observations

[abvidledUK]

After much deliberation and reading of previous CPF posts, I opted to try out DX Ultrafire Protected 880mah RCR123, along with the DSD charger.

I immediately swapped the supplied US style two pin PSU for a UK 3 pin Nokia charger, having read stories about the supplied PSU not liking UK 240v.

I partially discharged one cell, fully discharged the other, but not too low as to invoke protection, ( wonder what the low setting is for the protection circuit in these ? ) using a couple of the DX A1 Cree single CR123 torches.

Open circuit DMM volts read:
1) 3.71v partial discharge
2) 2.74v full discharge

Under load
1) 3.48v partial discharge
2) 2.46v full discharge

I then placed both cells together into the powered DSD charger, as above

Initial open circuit DMM volts across terminals on both cells was 3.68v
After 90 minutes, volts across was again equal, this time 4.11v, as the green charged LED came on.
(During the latter stages of charging I measured 4.21v)
Once green LED came on, current through the RCR123s was only ≈ 0.001ma, so no trickle charge there, at least not with the protected RCR123s.

As I understand it, the DSD charger gets around not having independent charging channels by initially charging using CC, until both cells are balanced, then finishes off the charge using CV.
During charging I noticed a very, very small rise in cell temperature, perhaps less than one degree, none in the DSD charger at all.
Almost indiscernible. Couldn't really feel any rise when cell held against nose !
Charge current rated at 450ma.

Certainly much less than the usual temperature rise in nimh cells when being charged, in their charger.


I then again discharged both cells in the A1s, high setting, until LEDs became dim, at the same time. (25 mins)
The A1's became very hot for 20 minutes.

Measured o/c volts were
1) 3.08v
2) 3.12v

So it would seem that the DSD charger does indeed quite well charge individual cells with unequal remaining capacities, even without independent channels.
(See photo of innards in this thread)
http://candlepowerforums.com/vb/showthread.php?p=1559323
with excellent before photo.
Such a simple circuit too, perhaps other manufacturers should copy.



Measuring the initial current consumption through the torch at the setting below, gave me an approx capacity for the protected RCR123's DX rated @ 880 mah of

a) High 790ma ≈330mah
b) Med 280ma ≈420mah
3) Low 50ma ≈500mah

So, in conclusion, the Ultrafire "880mah" Protected RCR123s have a capacity of around 500mah, they charge for around 90 mins in the DSD charger, which does have +ve and -ve marking, but etched into black plastic, hence my paper labels.

I did this, after despite checking, I managed to insert a single RCR123 the wrong way round, but the protection circuit did it's job, and when after 4 hours I still go a red LED, and spotted my error.

No measurable damage to RCR123 at all, nor to the DSD charger.

https://www.dealextreme.com/details.dx/sku.936

https://www.dealextreme.com/details.dx/sku.3273

https://www.dealextreme.com/details.dx/sku.16844

PS: Due to the slightly longer cell length due to the protection circuit in the base of the cell, two of these are too long for my P3D's

 

[Bonky]

or you can take white-out and dab it in/on the + and - markers. Stays on well and makes them much more visible.

 

[Mr Happy]

I believe you should not discharge your cells below 3.6 V open circuit, or about 3.0 V under load. If you discharge them to a voltage below 3.0 V open circuit (such as 2.74 V), you run the risk of damage to the cells, shortened life and possibly worse events than those.

Others will likely confirm, but discharging an RCR123 until the light goes dim is discharging too far. You should stop and recharge before this happens.

[Edit: but nice testing, however.]

 

[Monocrom]

So it would seem that the DSD charger does indeed quite well charge individual cells with unequal remaining capacities.
https://

That's assuming you are fortunate enough to get a DSD charger that even works, right out of the box. The quality control on the DSDs are about as consistant as the mental stability in a lunatic asylum. :thumbsdow

 

[Elliot]

abvidledUK: Thanks for the post - I odered then exact same items a few days ago. I let you you know how I make out when I get it in a month or so:naughty:

Elliot

 

[abvidledUK]

I believe you should not discharge your cells below 3.6 V open circuit, or about 3.0 V under load. If you discharge them to a voltage below 3.0 V open circuit (such as 2.74 V), you run the risk of damage to the cells, shortened life and possibly worse events than those.

Others will likely confirm, but discharging an RCR123 until the light goes dim is discharging too far. You should stop and recharge before this happens.

[Edit: but nice testing, however.]

Protected cell, but don't know what lower limit set is.

Probably a bit of a high current discharge anti-bounce.

 

[mudman cj]

The DSD does not use independent charging channels. The reason you noted cell heating during the imbalanced charge is because the cell with more charge was discharging into the cell with less charge. You probably exceeded the 2C discharge or 1C charging rule there. A good rule of thumb to avoid this is not to charge two cells in parallel if their open circuit voltages differ by more than 0.5 V.

 

[Mr Happy]

Protected cell, but don't know what lower limit set is.

Probably a bit of a high current discharge anti-bounce.

Well, it's your funeral. :shrug:

You seem to be saying, "If I don't invoke the protection I'm OK." I don't believe that is an accurate statement.

 

[abvidledUK]

[Edit: but nice testing, however.]

Thanks

 

[mdocod]

I have had great luck with my DSD for years. With nokia power supplies I like it better than my WF-139 since it doesn't over-charge during charging. I have one of the older 139's that trickle charges after the charge is supposed to be complete, so I only use it for auxilariary charging when the DSD is occupied, I try to remember to move the cells from the 139 to the DSD to finish off the charge before the 139 brings it above 4.20V to complete it's "CC" only charge method.

Eric

 

[Black Rose]

I think I'm going to order one of these DSD chargers.

I happen to have a couple Nokia power supplies from retired cell phones, so that should address any issues related to the wonky wall wart that comes with the DSD charger.

EDIT: My Nokia power supply (ACP-7U) only outputs 3.7V and 340 mA so that may not resolve the issue after all.

 

[p moore]

I have only had my DSD charger for a few days now. So far I am happy with the results.

 

[stefanj]

I just got my DSD Charger. I'm very pleased with it (have only charged 4 sets of batteries so far). The only down side of it is that the 18650's are a tight fit (not a problem getting them in- but a challenge getting them out) I'm going to put a rubber band on the one cell so I have something to grip to pull the cell out. Charge times for a 18650 was 8 hours- but the cells never warmed up even the AC adaptor stayed cool to the touch.

 

[craigshipp]

Interesting, but most of this is Greek to me. I do have a question. I just ordered the following. Will this kit serve me well?

Kit: 2 x
RCR123A 3.6V
880mah
Ultrafire
Protected
Li-Ion
Batteries &
TL-100
Universal
Li-Ion
Charger 16340

 

[Joe Talmadge]

You're probably better off starting your own thread, rather than raising one that's 3 years old -- we've learned a bit in the intervening time In any case, different people have different risk tolerances; for myself, since the house catching on fire is a possible outcome of poor choices and handling, I tend to be on the conservative side. In general, most people in this forum don't like Ultrafire's inconsistent quality and components, or the TL-100s's failure to follow the proper charging algorithm for these batteries. Personally, I wouldn't allow these in my house. There are folks on the forum whose risk tolerance is looser than mine, and who think what you have is fine.