Fenix PD35 & 18650 battery help

I just bought a Fenix pd35 and have been using Olight rcr123's to power it. I bought some Nuon 18650's today and it will work with every setting but the highest 960 lumen mode. It will shut off and only turn back on for a split second. Then I have to reinstall the rcr123's to change the setting off high to be able to use the 18650's again. if I run the batteries down to about a 85% SOC it works fine again. Why would this be? I bought this to mount on my fire helmet but I am concerned that it won't work when I really need it to.


Thanks

J-remy said:

I just bought a Fenix pd35 and have been using Olight rcr123's to power it. I bought some Nuon 18650's today and it will work with every setting but the highest 960 lumen mode. It will shut off and only turn back on for a split second. Then I have to reinstall the rcr123's to change the setting off high to be able to use the 18650's again. if I run the batteries down to about a 85% SOC it works fine again. Why would this be? I bought this to mount on my fire helmet but I am concerned that it won't work when I really need it to.


Thanks

Click to expand...

Are you using 3.0v/3.2v RCR123s in it?

I don't know what type of cell quality Nuon uses, but try a quality 18650 from Sony, Panasonic, Sanyo, LG, or Samsung--protected, or not and see if you can't get the turbo.

Sounds like you have a crummy cell.

If your Olights are 3.7v cells--4.20v hot off the charger, than you might be damaging your light.

Chris

The Nuon's are 3.6v and read 4.1v with my dmm right off the chargers. The RCR123's from Olight are 3.7v and read 4.1v off the charger as well. I use the RCR123's in my s1baton. I see now that the CR123's that came with the PD35 are 3.0v. The manual recommends 18650 3.6v/3.7v batteries.

J-remy said:

The Nuon's are 3.6v and read 4.1v with my dmm right off the chargers. The RCR123's from Olight are 3.7v and read 4.1v off the charger as well. I use the RCR123's in my s1baton. I see now that the CR123's that came with the PD35 are 3.0v. The manual recommends 18650 3.6v/3.7v batteries.

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Well, that might just be your problem.

I don't know what the driver specs are for the PD35, but I have a PD32 and I think it's 6.0v (max). I don't use the term 'RCR123' to describe 3.6v/3.7v cells, because we also have 3.0v/3.2v rechargeable li-ion LiFePO4 cells that are the same size as a 16340 (3.6v/3.7v) rechargeable cell, or a CR123A primary cell. It's confusing.

Since these 3.6v/3.7v cells can come hot off the charger at 4.20v (+/- .05v), stacking two of them means an total of 8.4v. If you have a 6.0v driver, that might be enough to blow like Krakatoa.

Chris

Wow,Thanks. I am obviously new to the battery world. The Olites have rcr123a labeled on them that's why I wrote that good to know. The Olites work fine in the light but the 18650 batteries are what I'm having the problem with. Do they not have the power to run the light or is it over loading the light? It is strange that they have to be drained below 85% SOC to work properly. I am thinking they are low quality cells.

J-remy said:

Wow,Thanks. I am obviously new to the battery world. The Olites have rcr123a labeled on them that's why I wrote that good to know. The Olites work fine in the light but the 18650 batteries are what I'm having the problem with. Do they not have the power to run the light or is it over loading the light? It is strange that they have to be drained below 85% SOC to work properly. I am thinking they are low quality cells.

Click to expand...

Get rid of the crappy cell and try something of known quality and health. You need to start ruling things out. For all I know, you blew your boost driver when you put in two 3.7v/4.2v in series, but I'm not a flashlight designer, so I can't say. My PD32 works perfectly on 18650s, but that's older light with less current draw.

I'm looking for the driver specs and don't see voltage, but on Turbo, the 850LM PD35 draws 2.88A, so we'll call it 3A. That's safe for most all quality 18650s, from the NCR-A/B Pannies, up to whatever. It's not a problem unless the light is broken, or the cell is bad.

Even the PD35 Tac. is probably only 3.0A on Turbo. Even two RCR123 3.2v rechargeable cells in series, can handle 3A. Two primary CR123A should probably be safe in limited amounts of burst.

Chris

I would not use 2x RCR123 (16340) cells in the PD35. In series that will be almost 2 volts higher right off the charger than the voltage of 2x CR123A. Manual doesn't say if 16340 batteries are approved but 2x CR123A is approved. I agree with Chris on the Nuon 18650 battery. It's an unknown brand among your fellow CPFers. You shouldn't have any problem hitting the high mode with a 18650 battery unless the battery is an issue or the flashlight now has issues.

My guess is that the PD35 is still good and you need a different 18650.

Thanks guy's. I will order some quality cells to use, Glad I asked.