Malfunctioning Imalent R60C - a fickle child?

A few days ago I bought the Imalent R60C from nealsgadgets.com. The light arrived safely wrapped in a cardboard box without any visible damage. While unboxing I discovered a very visible nick in the anodized bezel, leaving a slightly bitter taste in my mouth concerning Imalent being a premium brand. In order to check if everything works I firstly checked the battery voltages (all 4.02V), which was imho way too high for long term storage. After using the R60C for a brief moment I then noticed a sour, acrid stench inside the battery tube (a bit similar to cat pee). The negative poles of the Imalent batteries had burn marks, possibly from some residue that was burned by the high current. Besides that I did not notice anything unusual in the flashlight at this point of time.

In a next step I used alcohol and cleaned any excess grease from the electrical contact areas (brass ring, face side of the battery tube, springs, terminals of the batteries) to prevent any additional resistance / voltage sagging during operation.

Unfortunately, this flashlight shows a very odd behavior on turbo mode that I was unable to locate and fix so far.

Altough all batteries were fully charged, the light frequently and randomly turns off after triggering turbo mode while sometimes it surprisingly works. I assumed it would have something to do with the temperature sensor but this does not seem to be the case as you can see on the following videos. The tube was always screwed tightly against the head. I also noticed the battery indicator turning red on turbo or blinking red and green even with (almost) fully charged batteries. Obviously, there is some voltage sagging in the electric path. Of course, I did repetitive cleaning of all the electric contact areas but with no success. I know the Imalent MS03 had very similar problems in the first batch (see reviews from The_Flashoholic)... https://budgetlightforum.com/t/-/62301

A friend of mine bought another two R60C from Neal and they perform well down to voltages of 3.7V (#1) and 3.5V (#2), without any shutting off from turbo at all.

Please excuse my miserable skills in taking these videos.

Video #1:

Video #2, taken a few minutes after cooling down the light:

Video #3, taken again after another cooling break:

A few initial thoughts on the root causes:

  • defective NTC sensor on the driver, causing wrong thermal sensing
  • defective PCBs on the Imalent batteries? (I cannot validate that as I do not have any fitting spare batteries)
  • conducting issues on the bottom PCB in the tailcap

Any ideas what I could have overlooked to check/test? Has anyone else successfully solved the above mentioned error pattern?

I sent Neal an e-mail to see what he can do but I doubt he will respond at all. I am torn between raising a PayPal dispute if he fails to respond or requesting support from Imalent's 60 month warranty. The latter case could mean more hassle as Imalent maybe requires me to pay for return shipping to China which is about the price of the light, rendering this option to nonsense.

Thanks for your comments. I will keep you updated about any progress.

My guess – a battery (or all three) vented some electrolyte and the Battery Protection Circuit kicks in. You would need to find some 21700s to check that. The vented electrolyte can also seep into the driver and being conductive, could make it misbehave at high output.

I’m no specialist, just had a somewhat similar experience with a modded Amutorch SD3 which I had the misfortune of cleaning the driver with a caustic solution.

P.S. I’ve had a $100 + light that mysteriously showed a ‘nick’. My eye couldn’t help focusing on the blemish. A bit of black felt marker, although not the same sheen, covered the eyesore. Today, I have to look for the nick, if I do carefully inspect.

Imalent and others really sell their peace of mind warranty but I feel for L-P as when you have an issue and you dig deep into the warranty to find out you have to freight the light to China, well it kinda renders the warranty useless. I think Imalent has cost themselves a bunch of sales from weary folk who don’t want to take the ‘chance’. I hope you find a solution, what a bumma!

Thank you guys for your comments.

Both battery terminals and driver appear absolutely normal. No signs of leaking or venting so far, fortunately. The strange odor seems to come from the bottom PCB, possibly due to overheating / extreme currents that have burned something. I have recharged the batteries internally several times now and they seem to work okay…but it is hard to tell without looking inside.

The nick seem to be a result from an impact. I feel reluctant to put the blame all on Neal but it arrived in this condition already. Not sure if this was a returned light.

I am waiting for Neal to respond to my e-mail. Should that fail to work out, I hope PayPal will side with me. Last option would be asking Imalent for support. Gatzetec, an official German Imalent retailer kindly offered to assist in contacting the manufacturer.

So much for buying expensive flashlight.

After re-reading, it would seem the culprit may lie in the tail cap. Strange, I assumed the batteries are 3p and there shouldn’t be any electronics there. 3 springs, either a PCB or a mechanical retainer.

You will have to look in there. I mistakenly had read there was a film of chemicals on the inside of the battery compartment. Very bad stuff the electrolyte.

Still, it’s best not to use protected cells for high current lights. You’ve been around enough to know of the many who had turbo problems with these cells.

A bit of math: 6 XHP70.2 @ ~8 amps each* on 3 cells equates 16 amps draw. I never heard of a protected cell that can handle such current. But then, I’ve never seen 21700s with a protection.

  • From Köf3 - TLF LED test, to deliver 18,000 lumens (claimed) the emitters would each throw some 3,000 and that at 4 Amps / 6.5 Volts. Assuming a boost from a single cell to double the voltage, doubles the current draw.

Most likely a customer return that was mistakenly put back on the shelf.