can the UF-502B SSC P7 take 2xCR123A without damage

I just received th3 UF-502B. With the UF 18650 battery* it is a very disappointment light! But really nice when I put 2 CR123A (consumable) batteries. The specs state it is a 1x18650 only. Is it possible to damage the electronics or emitter with this battery configuration?

I also have a second general question - If the driver is regulated, how does adding more battery power (voltage) make it brighter? It would seem the lumens would stay the same and only the runtime would be better.

*Yes, I’ve learned that the UltraFire 18650 “3000mha” batteries suck, and maybe that’s the problem?

Where did you get it? Most drivers can take two 3V primaries and I think its brighter because those UF cells are crap. ;)

I think you will hurt it if you run it for a long time.

The light and the batteries came from DinoDirect. I didn’t know what I was doing at the time, I hadn’t found this forum and the false lure of “900 lumens” for a $13.00 flashlight duped me in.

UF battery inflates capacity, but still much higher capacity than 2x123. UF 18650 it has no problem deliver 2.8A. It’s the driver, change it to 8x7135 instead.

I appreciate the suggestion, but I’m sure I don’t have the soldering dexterity involved. How about a replacement drop-in based on that driver or similar? Are there such animals, and if so what size do I look for?

Thanks for the answers so far!

my random thoughts…

First of all, invest in a multi-meter. Theres no way to really know what your cells & light are doing without one (and even then with a MM its still an estimation, albeit a much more accurate one).

Those red 3K ultrafires are really a crap-shot. They pretty much run the gamut on those… anything from old re-shrink’d laptop harvests to smaller lithium cells in a tube with mystery powder. If you have a multi-meter you can measure tailcap current, and use run times to number crunch back and estimate battery capacity from that.

Another thing you can do is discharge the cell so the light starts to dim, and time how long it takes for your charger to peak. You can use this info to number crunch estimate the capacity of the cell if you know the charge current of your charger. If your charger charges at .5A and your cells are topping off in 45 minutes then theres something wrong with that cell. But even then, its a ballpark estimate without a multimeter.

A well designed P7 light should draw anywhere from 2-2.8A at 4,2V depending on its thermal design and intended use (spot-ON or constant-ON). I have an under-driven P7 light and it only draws 1.8A at 4.2V, and even then it will do ~315 OTF. I would start with baselining your cells first, find out where they are at. If they are saggy and under performing for capacity upgrade to Panasonic or Sanyo cells. After that, upgrade to a drop-in that performs more to your liking.

Yes you can DEFINITELY damage the circuit with excess voltage. Been there / done that. I don’t think exceeding the recommended Vbatt is a wise decision.

You didn’t specify, so I’m thinking you bought this one.

Yes it will run on 2x 3v cells. But it is very likely harm the driver if used long term.
As others have stated the UF3000’s and Ultrafire branded batteries in general , are a crap shoot. You can get decent ones, but a large portion are not worth the money.
As suggested ,use a DMM to test tailcap draw.

I’m not discounting battery problems at the end of it. how well a light functions,
depends largely on the quality of the battery.
I am however , going to suggest you do the easy things first.
Start by disassembling the light & clean and lube all the threads. Make sure the reflector is tight & that the spring on the pill is making good contact as well.
Assuming you don’t have lube on hand. Stop at your local auto parts store & buy a small tube of the stuff used for plug wires. ( dielectric grease ) I say “small ” because it doesn’t take much.

When cleaning ,pay particular attention to the threads on the tailcap.
Not only where it screws onto the body, but where the
switch & retaining ring contacts the cap.
On some lights,I’ve had to add strips of aluminum foil around the threads to make a good connection. 501/502’s are a good light,but thread quality can vary wildly.
Members have noted problems ranging from tailcap connections to bad solder joints on the led. This is not exclusive to one brand or style.

You mentioned a replacement drop-in. Manafront offers a very well regarded replacement. http://www.manafont.com/product_info.php/ultrafire-cree-t6-3mode-memory-led-dropin-module-42v-max-p-5178 Modes are Hi > Mid > Lo.
And there are members on this board who make incredible drop-ins as well…

Keep us posted as to what you find.

Kramer, thank you so much for taking the time to explain these things to me. Instead of being a problem, this cheap light is becoming an excellent learning tool - thanks to you and the others on this forum.

I already own a semi-good VOM, so I’m good there. I’m not sure how to measure tailcap current - isn’t the tailcap ground? but I’ll do a search and find out.

Also where are you getting 4.2V, is that the regulation from the driver (since the 18650’s are 3.7V)?

Thanks again for being so helpful and sharing your expertise!

— Robert Baker

Yes, exactly right! So I won’t run it with the CR123A’s, thanks for letting me know.

This is perfect. As I said to Kramer, I am very honored to be personally given this education. I will spend this time and clean/lubricate/check connections. Once again, this will be a good learning experience, and something to practice when I get better lights in the future. I was wondering why members would start reviews by saying “I took everything apart”, they’re checking everything and making sure it is correctly cleaned, lubricated, and built.

Thank you for this reference. If I can get a decent bright light out of the SSC P7, I’ll leave it as is (as long as I can get it to work properly) & save my money for a name brand (Fenix or Zebralight). But I will save that link since I wouldn’t know how to shop for the drop in. I did see the members who are modding drop ins, pretty reasonable prices - I have my eye on a Nichia 219 to see how Neutral White looks.

So thanks again for taking the time to give me very wise and calm solutions. I’m looking forward to my continued education!

— Robert Baker

Sure np. The 4.2 refers to the freshly charged 18650 cell voltage. Although you’re right nominal (average) voltage through the discharge will be more like 3.6V. In reality a healthy 18650 cell will only remain at 4.2V for ~15-20 seconds tops with a ~2.5A draw.

OOPS I forgot to say , Welcome Aboard , Glad you joined us !

I appreciate your kind words and that you value our input…
We love our hobby / addiction & are willing to freely share what we know.
This a great place to be. I’ve been a member for a few short months , and learning something new all the time. 8)

Your 502b is a good light, don’t underestimate it. :slight_smile:
And there are things that you can do , to make it even better. :wink:
I’ve put mine thru hell & it’s preformed like a champion.
The things these inexpensive light are capable of , is amazing.
The reactions when people see them perform and finding out how little they cost
, is priceless… :bigsmile:

oops I missed this one… Just set your meter to read DC-current, and plug the probes into the correct terminals. Touch one probe to the battery tube and the other to -B. Make sure your meter and probe wires can handle a ~10A draw and you’re set.