Why did my P61 bulb blow?

I took my SF Legos to play with last night. I have a 6P with a Z59 on a KR2-BK kit. I was running the LED P60L and decided to run the incan. P61. The P60L was running good on the B65 whichI checked with a DMM at 4.6V. The P61 went dim in about 2 seconds so I charged the battery. The battery was 5.7 went I took it off the charger. I put the battery and it went on for about 1 second and it died. It didnt look like a 120 lumen burst. Upon further investigation I saw that my P61 had went I saw that the filament was burned on one side. I didn't see any black residue and cloudyness in the envelope. What could have gone wrong? Was it the Z59 clicky its been one that has been working when it want to? Will SF warranty my bulb?

Was that the first time you turned on that particular P61? If so, I've had them warranty bulbs that blew prematurely like that.

Yeah, I don't think it is normal for a B65 to blow a P61 since that is a standard SF configuration, but I don't own one so I have no experience.

Chrontius my P61 was on a C2 I have when I swapped it. It was working fine. I'll call SF tomorrow.

I just got off the phone with SF CS. The Rep. told me that the KR2 kit was not meant to run a P61 bulb, he said it was only for the P60 and the P60L. He said the B65 battery underpowered it and blew the bulb. I told him I had tested the battery at 5.70V and he said that that was about the right voltage for the B65. I think this was an expensive mistake. I dont remember ever reading that the KR2 was only for the P60 or P60L. They should state that in the packaging and product descriptions. I thought it would work since it did on a P60 I just thought i would get crappy running time. I just thought I would pass this on. Was it the bulb current draw from the P61 under load? I did more searching and found some old threads where someone said to wait 5 min. and someone else say an hour after taking the battery off the charger and putting it in the flashlight. I said this to the CS Rep. and he just stayed quiet I know he knew I was a CPFer.

That sounds a little bogus. Maybe check the papers you got with it to see if it mentions the P61 as a possible combination. I'm sure it doesn't mention the P60L unless they recently updated the publication.

BIGLOU said:

He said the B65 battery underpowered it and blew the bulb.

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wtf? under-driving a bulb kills them?
sounds like the opposite of reality.

I always thought underdriving bulbs was bad for them...

Maybe it was nearing the end of it's life and the underdriving killed it? :shrug:

Weird :thinking:

DimeRazorback said:

I always thought underdriving bulbs was bad for them...

Maybe it was nearing the end of it's life and the underdriving killed it? :shrug:

Weird :thinking:

Click to expand...

underdriving is bad because it inhibits the tungsten atom recycling process brought upon by the halogen cycle due to lower than designed envelope temperature.

I didn't see any black residue and cloudyness in the envelope.

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If the lamp died of an underdose of electrons, there would be [pardon the pun] surefire signs of tungsten residue on the lamp envelope, in this case, the thread op spoke nothing of this. Besides, it will take a long time for it to blow, in this case it blew immediately.

BIGLOU, is there any white deposits [or blue] at the base of the envelope? it may be a clue to a possible leak in the envelope.

Thanks for the info Illum!!

:twothumbs

I called SF back and spoke to someone else after thinking maybe I got short changed. I told the Rep. my sad story and he said," so you want us to sent you a courtesy replacement". I was like that would be cool since I had once again checked the website product description and found no evidence of it saying it was only for the P60 and the P60L. The CS Rep. told me he was having problems with the system and was going to send me another one once it was up again. I was able to pick the Reps. brain for while on some stuff while he waited for the system to go back up. I just wanted to advise for some of us who play SF LEGOS and have the KR2 kit and want to rock the P61.

Good news my friend! :twothumbs

DimeRazorback said:

I always thought underdriving bulbs was bad for them...

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ohhh, ok. learn something new everyday.

Of course "bad" should NOT be "instant-flash bad".

Even without the thungsten-iodine process, the filament should happily burn for many hours...

I've only blown one Surefire lamp that I can remember over the years. A P90 that had probably a half hour or less runtime on it if I remember correctly. I have some Surefire bulbs with hundreds of hours on them still going strong.

alright, while waiting, here's something you can do
https://www.candlepowerforums.com/threads/237648

I'll probably be quickly corrected by the experts if I'm wrong.

I remember reading awhile back that the P61 was a 4.8 volt lamp, due to the voltage sag of CR123 batteries at the 2+ amps that it draws. A ni-cad at 5.7 volts probably won't sag anywhere near 4.8 volts.

I suspect that the bulb was overdriven.

I had a P61 went on me using the KR2 w/B65 on a round body 6P w/ a z41. I lights up for about 2 seconds.

When DimeRazorback bought a P61 on the MP for his strider M2, I caution him not to use the P61 on the B65. otherwise it will went

I don't see any discoloration on the bulb envelop !:thinking:

You are lucky you're located in surefireland (USA) I can't get any courtesy replacement over here!!:sigh:

Deputy T. said:

I'll probably be quickly corrected by the experts if I'm wrong.

I remember reading awhile back that the P61 was a 4.8 volt lamp, due to the voltage sag of CR123 batteries at the 2+ amps that it draws. A ni-cad at 5.7 volts probably won't sag anywhere near 4.8 volts.

I suspect that the bulb was overdriven.

Click to expand...

My thoughts exactly.

mikevelarde said:

I had a P61 went on me using the KR2 w/B65 on a round body 6P w/ a z41. I lights up for about 2 seconds.

When DimeRazorback bought a P61 on the MP for his strider M2, I caution him not to use the P61 on the B65. otherwise it will went

I don't see any discoloration on the bulb envelop !:thinking:

You are lucky you're located in surefireland (USA) I can't get any courtesy replacement over here!!:sigh:

Click to expand...

That is strange, it should have worked fine without the lamp blowing. The KR2 w/B65 battery pack was designed as the rechargeable option for their 6 volt lamps.

I've never run a P61 on one, but that should not have happened by my estimation. The battery pack is not that strong for the size, the runtime is fairly short with the P60. I was never impressed with the setup.