Batteries and the 'PD'

Most of my experience with flashlight batteries have been re chargeables.
They expire with some warning in the PD. However I used a primary cell yesterday ( Surefire CR123a ) and the light just suddenly stopped working. First I thought that something had gone wrong with the 'electrics' but a fresh re chargeable got her going again. The voltage on the primary was 2.81 volts.
Is this the normal way a primary expires in a PD?

If the threshhold of 2.5V of the driver is met it just shuts down. At least I guess this is th reason. Normally though I change my batt before this at the slightest hint of the "out of regulation flicker", so I do not encounter this situation too often,.
bernie

David,
The Wiz2x2 will shut down when Vin is somewhere around 2.5 v. As the Vin approaches this, I have seen flickering in the run time graphs as well as in use; especially if the current demand is high. This is one of the reasons I stay away from setting the high level above 600 mA. I don't recall what you have under your hood but I have not encountered the situation you have described. Hopefully others will chime in here. You may also have just experienced one of those cases where the SF primaries have reportedly just "given it up" Towards the end of usefulness of the CR123, the driver can be asking for a couple amps from the cell and perhaps it passed out! :shrug: :thinking:

Do you think you were near the end of the cell's capacity?

There is much we still don't know about the behavior of these drivers and cells! If you look at the run time graph of the HD45 I posted in that thread, you can see in constant on on high, there was a moon mode but in constant on in low, the output dropped like a rock! Bear in mind that this is on 2xCR123 so for the Vin (under load) to get to the 2.5 threshold, these cells really need to be "spent".

McGizmo said:

Do you think you were near the end of the cell's capacity?

.

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I do not use many primaries, but thought that the battery was about half full.
I had been using the PD on max ( 580 ma I believe ) off and on for 5 minute sessions.
Then I put it down for 1/2 hour approx. When I picked it up I switched on low power and it worked for 5 seconds and then went out and never worked again with that battery.

Voltage read 2.8 volts and did not recover.

My re chargeables suck down to 2.6 volts and then light goes out. Wait a minute and you can switch back on and get a few seconds more time on low.
The re chargeables always seem to jump back to just over 3 volts.

I don't know if the situation was atypical or not. Certainly if the cell was down to half capacity, I think atypical. :shrug: My experience has been that I can get good low but see some flickering and or low output in high for indication that the cell is spent.

Hopefully others will chime in here.

It is fairly rare but you might have been the victim of SSFBDS, Sudden Surefire Battery Death Syndrome. I've had it happen to me a couple of times with relatively fresh batteries a couple years ago, but haven't experienced it recently.

I had this situation once ... used the PD on low, then switched to high and it went super-dim after a fraction of a second with bright light and then died completely some seconds later. This was with a nearly spent SF123, so it didn't make me worry. I interpreted it as an almost-dead cell that could just feed the low-mode and finally died after the Wiz2x2 angered it with the demand for high.
bernie

Kiessling said:

... finally died after the Wiz2x2 angered it with the demand for high.
bernie

Click to expand...

I love that "angered" part - a current driver from Wayne with an attitude

Will

I've noticed several times that the PD suddenly won't turn on. I only use my PD in short bursts though, quick checks of this or that, and the most time it typically spends on is for about 20 seconds. I usually get at least two weeks out of a battery so I don't sweat it much. (Yes, I use SF primaries, at least for the time being.)

Never did actually test the cells (never have time usually.) I might sit down and try that next time.

kennyj said:

I've noticed several times that the PD suddenly won't turn on. I only use my PD in short bursts though, quick checks of this or that, and the most time it typically spends on is for about 20 seconds. I usually get at least two weeks out of a battery so I don't sweat it much. (Yes, I use SF primaries, at least for the time being.)

Never did actually test the cells (never have time usually.) I might sit down and try that next time.

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Well my problem was definitely the battery. A day later, the battery in question had suddenly dropped from 2.8volts to Zero volts. So I suspect that it was a faulty cell. It was old stock. Once I got back to using re chargeables, everything settled down.

Just happy it was not the PD.

Anglepoise said:

Just happy it was not the PD.

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Guess you're not the only one ...
bernie

Not trying to highjack this thread but figgured there was no need to start another thread. Can I use unprotected rechargables or do I need protected with the PD?

The Wiz2x2 has a cut-off at about 2.5V so unprotected cells should do fine. But I am not the cell-expert here.
bernie

Apart from the odd time, like above, I have used rCR123a unprotected cells with great success. The unprotected definitely have a little great capacity.
My PD cuts out at 2.6 volts, and my Aleph II, with the Wiz2 driver is about the same. I use the excellent Nano charger from member AW.

Where you have to be careful with un protected cells is if you have an application that requires two batteries. Now you can potentially run into problems of polarity reversing and other nasties that could be dangerous.
Fire, overheating, explosion etc. :bump:

Anglepoise what type of runtime do you get on high from rechargeables?

sbebenelli said:

Anglepoise what type of runtime do you get on high from rechargeables?

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I do not know.Definitely not as long as primaries.
I have never graphed this but others have in the 'PD' FAQ.