Fenix UC40 UE - charging issues

Hi everyone,

I hope that someone can offer some assistance please.

I have had my UC40UE for a couple of weeks now and it has been working absolutely fine - once I'd taken the dust caps off

I came to use it today and it would not switch on (I got an extremely brief flash of light, but nothing more). I popped a couple of CR123 cells in and the light fired up (but there doesn't seem to be a Turbo on CR123 - Turbo seemed to be the same brightness as High on CR123, is this right?) so the light seemed to be OK.

So I put the rechargeable battery back in the light and hooked it up to my computer and a green light came on which would seem to indicate that the battery is charged. So I tested the rechargeable battery with my multimeter and it reads 1.09 volts which I would think is WAAAYY too low.

Is my rechargeable battery dead already? If so, what could have caused it? They have a protection circuit to stop over-discharge/over-charge, don't they?

I hope that I can get it working again, as I bought it from the US and shipped it to the UK, so it would be expensive to have to ship it for warranty repair.

EDIT: Update - if I plug the light into a wall socket USB charger, the charging LED is still green, but I can then turn the light on. On Low, the charging LED is still green, but on Medium and High the charging LED is red (when I switch to High it drops down to Medium after a couple of seconds).

Thanks for reading!

All the best,

Face

Hi,

Could a mod please move this to the batteries forum as I think it is a question that is better placed there.

Thanks,

Face

Yes, your battery is dead! Please don't charge it anymore, you can harm yourself or burn your house down.

It should be deffective, contact Fenix for a repair.

Thanks for the reply.

That's what I thought - but also the light won't go on Turbo mode on a pair of CR123 cells - it will only go up to High so I am wondering if there is something wrong with the light itself as well.

It is a real PITA as it is going to cost me about $25 to return it for warranty which is quite a bit to be out of pocket.

Thanks again,

Face

Have you tried using an 18650 type of battery?

radek_t said:

Have you tried using an 18650 type of battery?

Click to expand...

+1

Hi again,

I'm afraid that i currently don't own any 18650 cells - but please see further below as I would welcome your comments on some 18650 cells

I have spoken to my dealer and they are very kindly going to send me out a replacement rechargeable battery.

I also mentioned to them about my light not hitting Turbo on 2 x CR123 cells and they tell me that this is because "Panasonic and energizer batteries are known to not have the level of mAh to bring in the turbo brightness even though they register on the volts... They just don't have the mAh to get your turbo...." - so at least I know to not use these brands of CR123 in the light. A pair of own-label CR123A that I have tried subsequently DO fire up the Turbo setting so I know that the light does work OK.

Also, I was going to buy a pair of EagleTac 3400mah 18650 cells to use in my UC40 UE as well as other lights - but do you think that these EagleTac cells will have the "power" to get the Turbo mode working (just double-checking after my experience above with 2 x CR123) - don't want to buy the EagleTac cells just to have them not work on Turbo either.

Any further advice would be great.

All the best,

Face

mAh rating has nothing to do with if it will power Turbo mode. The higher the mAh is, the longer the runtime is. It's a combination between Voltage and mAh. Eagletac 18650's will power all lights. I use only Eagletac branded cells.

About how many times had you charged/used the battery before failing?

Hi everyone,

I had only done one full charge on the built-in battery before it died.

My dealer has sent me out a new rechargeable battery pack so hopefully all will be back to normal in a couple of weeks.

With regards to the known Panasonic and Energizer issue in regards to not having enough "umph" to get Turbo mode, what CR123 brand would you recommend that would have the "umph" to power up Turbo mode?

Lastly, I have just had delivered today 2 x EagleTac 3400mah 18650 cells. I popped one straight in the UC40 and it wouldn't fire up Turbo mode either. I put the 2 x 18650 cells on the multimeter and they both read 3.67v; I've now put them on a full charge but I'm a bit worried that they are not going to fire up the Turbo mode either - even though they are spec'd at being able to deliver 5A. Surely these EasgleTacs should be enough for Turbo mode?

Thanks again, everybody.

Face

Face said:

With regards to the known Panasonic and Energizer issue in regards to not having enough "umph" to get Turbo mode, what CR123 brand would you recommend that would have the "umph" to power up Turbo mode?

Lastly, I have just had delivered today 2 x EagleTac 3400mah 18650 cells. I popped one straight in the UC40 and it wouldn't fire up Turbo mode either. I put the 2 x 18650 cells on the multimeter and they both read 3.67v; I've now put them on a full charge but I'm a bit worried that they are not going to fire up the Turbo mode either - even though they are spec'd at being able to deliver 5A. Surely these EasgleTacs should be enough for Turbo mode?

Thanks again, everybody.

Face

Click to expand...

Those Eagletac should be able to power the light on Turbo. I use Eagletac batteries in all my lights. Try Duracell CR123 batteries. Didn't have any problems with those at all.

Hi KJ2

Thanks for the quick reply.

I have just found a table the kind-of correlates Li-Ion cell voltages with cell capacities and it would seem that 3.6v is almost flat so here's holding out hope that when they are fully charged all will be well with the world

Regarding the CR123s - are Panasonic and Energizer really known to not have a lot of "umph" to them?

All the best,

Face

Face said:

Hi KJ2
Regarding the CR123s - are Panasonic and Energizer really known to not have a lot of "umph" to them?
All the best,
Face

Click to expand...

Not that I know of. Both brands are well known and make good products. You could ask CPF-member HKJ if he knows more. HKJ knows a lot
on battery-subject.

Hi,

OK - I've charged the 2 18650 cells and using these 18650s I now get a low, medium, high and turbo mode - however the turbo mode just doesn't seem to be anywhere near as bright as it should be - it's not much of a step up from high.

I've got a gut feeling that something is just not right with this particular light but I just can't put my finger on it. I will wait for the new cell from my dealer (who has been brilliant so far - very helpful and efficient) and go from there.

Cheers,

Face

The difference between high and turbo is very small for the eye. A turbo mode with 1600lm seems to be twice as bright than the high with 400lm. That is why the turbo looks not more than twice as bright than high. Only ca. 50% brighter.

I have an SRA40 which is also rated at 960 lumens, so when it is dark tonight I will try a ceiling bounce between the two lights and see if they are broadly similar - that's the only way I can think to test unless anyone can chime in with any other ideas

Face said:

I have an SRA40 which is also rated at 960 lumens, so when it is dark tonight I will try a ceiling bounce between the two lights and see if they are broadly similar - that's the only way I can think to test unless anyone can chime in with any other ideas

Click to expand...

If you use a smartphone, you can download a free photography light meter app and use that to objectively meter the output differences between different modes or lights. I like bouncing the light horizontally in a narrow hallway, matching the total beam sizes - bounce off one wall, meter off the other. If you want to get into it, you can use shutter speed, or EV + formula, to meter lumens for any mode from a know calibration point.

That's a great idea. I guess consistency of readings is more important than overall accuracy so that I can make a like-for-like comparison.

I just did a quick test by (not a totally dark room at the moment) using the same method as yourself and my SRA40 on High was 328 (surprised how consisted the app was - every time I turned the light off and on again, I got the same reading).

Then my UC40UE with Eagletac 18650 on Turbo was 229 each time.

Then the UC40UE with 2 x CR123 on Turbo was 440 each time.

I will try properly later when it is dark as see what happens, but I do think something has happened to this light - perhaps something that also killed the rechargeable battery at the same time.

Thanks,

Face

reppans said:

If you use a smartphone, you can download a free photography light meter app and use that to objectively meter the output differences between different modes or lights. I like bouncing the light horizontally in a narrow hallway, matching the total beam sizes - bounce off one wall, meter off the other. If you want to get into it, you can use shutter speed, or EV + formula, to meter lumens for any mode from a know calibration point.

Click to expand...

Which app did you use Face?
@reppans do you recommend any particular app for android?

I have an iPhone, but I think they all work about the same... make sure you get one that has 3 variables (aperture, ISO, shutter speed) where you fix 2 and the meter solves for the 3rd, and will also report EV. As I mentioned above, you can calibrate it to become a lumen meter. $5 in a hardware for plumbing elbows makes a nice "lightbox" too. DSLRs light meters work great too. All that said... you may not want to know the results/truth - it has ruined some FL brands for me.