QIII question??

I've heard that you can use rechargeable 123's with the QIII. My question is which would be better. Protected or Unprotected 123's?? Any info that you guys and gals could provide would be greatly appreciated. Thanks.

Happy Dark Trails

I always feel better using protected cells. Protection circuits both protect the cell from damage (user abuse from operating it outside of its intended range) and helps prevent "rapid venting with flame" (explosion).

Protection circuits:
1. Prevent overcharging
2. Prevent overdischarge
3. Limit the maximum current from the cell

One drawbacks of protection circuits is that they consume space that could be used for the battery and results in slightly less cell capacity. As well, with some high current lights, the cell protection can trip due to high in-rush currents. IMHO, the benefits of protection greatly outweigh these drawbacks.

Given the choice between protected and unprotected I would choose protected.

Additionally, since the Q3s do not have a low voltage cutoff, protected cells are advised.

with all the posts on exploding batteries I know it's the only way for me...

I always fear I'll bump it, it'll turn on and I won't know....an hour later...BOOM!

Note that there is a far smaller risk of fire, etc w/ Li-Ion than primary lithiums - main risk on Li-Ion rechargeables is ending up with a dead and unchargeable batt

I use non-protected 123's in my QIII all the time. Works fine and it's single cell so I don't worry about reverse charging. When the light starts to flash the cell is flat enough to charge again. Just remember that if it flashes and then goes off it is still turned on so if you leave it, the cell will be ruined. Just take out and recharge when it starts flashing.

Jay R said:

I use non-protected 123's in my QIII all the time. Works fine and it's single cell so I don't worry about reverse charging. When the light starts to flash the cell is flat enough to charge again. Just remember that if it flashes and then goes off it is still turned on so if you leave it, the cell will be ruined. Just take out and recharge when it starts flashing.

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flashing? never seen that w/ RCR in a QIII.

when the light begins to dim, time for a recharge.

What can I say, mine starts to flash when the cell gets low. It is one of the early ones, even has a normal clickie.

Mine just suddenly gets really dium when the cell goesd flat. It goes from really bright to "moonlight" mode in about 8-10 seconds. That's when I stop using it and pop in a freshly charged cell.

PhotonWrangler said:

Mine just suddenly gets really dium when the cell goesd flat. It goes from really bright to "moonlight" mode in about 8-10 seconds. That's when I stop using it and pop in a freshly charged cell.

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same here.

A better solution would be to replace the stock driver board with a flupic board which accepts voltage up to 5.5V

yazkaz said:

A better solution would be to replace the stock driver board with a flupic board which accepts voltage up to 5.5V

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Why? What difference would that make to whether he can use unprotected cells ?

Jay R said:

Why? What difference would that make to whether he can use unprotected cells ?

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Might not make much difference to that regard, but at least it's safe to use those 3.7V rechargables. Heard the stock board can't handle the extra voltage very well......

yazkaz said:

Might not make much difference to that regard, but at least it's safe to use those 3.7V rechargables. Heard the stock board can't handle the extra voltage very well......

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where did you hear that?

.

Actually, I told him. It is well known that the stock board is only a boost regulator, and not a buck. Consequently, the use of a RCR fully charged will put the LED into direct drive and will probably overdrive it whenever Vin exceeds Vout. Depending on the Vf of your particular LED this may or may not be a problem. The excess heat from the LED coupled with the heat from the higher current passing through the circuit and the poor stock heat sink has caused some to fry their stock circuit, not to mention the loss of output from the LED due to overheating of the die. At least that is what I have read in these forums...

mudman cj said:

Actually, I told him. It is well known that the stock board is only a boost regulator, and not a buck. Consequently, the use of a RCR fully charged will put the LED into direct drive and will probably overdrive it whenever Vin exceeds Vout. Depending on the Vf of your particular LED this may or may not be a problem. The excess heat from the LED coupled with the heat from the higher current passing through the circuit and the poor stock heat sink has caused some to fry their stock circuit, not to mention the loss of output from the LED due to overheating of the die. At least that is what I have read in these forums...

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Okay, so is not the *board's* inability to handle the 3.7V, it's the extra *heat* that is the issue. You going to have the same problem with a Flupic left on highest output for while. You can attempt to relieve some of the heat by matching Vf and using a better heatsink .

Running mine on a rechargeable 123 gets it no hotter than a primary cell. In fact, it's probably the coolest running light I have.

the q3 with r123s is a beast... it seems to put out as much as my u2 on level 4 or 5.

-david

The hot spot is a bit spread out so it's an excelent 'flood' light

Randy Shackleford said:

Okay, so is not the *board's* inability to handle the 3.7V, it's the extra *heat* that is the issue. You going to have the same problem with a Flupic left on highest output for while. You can attempt to relieve some of the heat by matching Vf and using a better heatsink.

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I agree that Vf matching is a good idea if planning to use the stock board with rechargeables, and a better heat sink is even better!

Since it is hard to say what current level is the limit before too much heat builds up, it would be safest to either use a 3.0 V battery with the stock circuit, replace the circuit with one that can still maintain 750mA to the LED from a 4.2V rechargeable, or one of the previously mentioned solutions (Vf matching, new heat sink, new circuit to control maximum current level). But I have heard of people using a stock Q3 for quite a while using rechargeables without a problem - YMMV.