Interesting, it would say that there is not quite enough contact pressure as you guessed. Must be variance in the spring tension is the only thing I can come up with.
Totally agree
I ordered a silver WT90 from Banggood 6 days ago and its estimated to ship today. I’ve been reading this entire thread and I’m on page 37 out of 50 so far.
Is the parasitic drain from the carrier not solved?
I consider this issue to be a major problem. I don’t want a flashlight that will kill my batteries in less than a year just by sitting still - and I can’t easily do a mechanical lock out on it to solve the drain like every other light I own. Opening the light, pulling out the carrier, and pulling out 3 cells is an absurd process to go through to prevent a simple machine from killing expensive batteries. The light should fit protected cells if its designed with a carrier that drains batteries. I also don’t want to remove the USB charging from the light to resolve the issue, as the USB charging and power bank are important features to me.
It was significantly improved in the latest version. I forgot the exact numbers but it was at least 18 months IIRC before it would drain the cells, possibly closer to 24 months. This is pretty good when compared to most e-switch lights out there, I just prefer longer on the lights I work on.
You can eliminate the carrier drain completely if desired by removing the USB charging. Takes a little soldering skill but pretty simply stuff or someone else can do it for you.
Thank you. I’m on page 41 of reading through the history now and I have not got to the part about the improved parasitic drain, can you link me to where it is discussed? 2 years is reasonable… less than a year is really bad. It still really sucks that the carrier on its own will drain the batteries (no quick mechanical lockout to stop this).
You mentioned a few times that the USB charging circuitry is not meant for low drain applications… Well I have a ton of portable power banks, which are all about USB charging circuitry, and they don’t drain themselves. I have one that is almost decade old that I just checked (haven’t recharged it in years) and its battery is still full (4 out of 4 LEDs are lit up, which is all I can determine from its interface since the battery is sealed) - this power bank is also a cheap Chinese no brand one. If a super cheap no brand Chinese power bank can get this USB circuitry right, then there is no excuse for the flashlight makers to not get it right.
Sorry, I don’t remember where it was discussed. I talked to the manufacture late last year though and they confirmed that they had improved the drain to an acceptable level.
The issue with the charging and the drain is that they wanted a fully featured high current USB C charge controller and also a FET controller for the cells to keep them from needing a mechanical lockout.
These are all nice features and pad the feature list but I tend to avoid them due to the issues like the parasitic drain that can come with them. I was overruled on this though and they did the charging without me.
I did look into it a little back when the issues was found and I had to agree with the engineers, there were sadly no good options for the controller that was available and able to do everything they wanted with significantly less drain.
Something would have to be sacrificed and with the chip shortage the last few years, redesigning it was not a practical option.
Basically the solution they came up with was the best option all things considered and it was an acceptable drain level. I don’t fault them for that, just wish covid didn’t exists and other options would be more practical.
I’m confused about that line…. It sounds like your saying they designed it such that the cells do not need mechanical lockout…. But they do indeed need it because there is parasitic drain. The reason the parasitic drain is such a problem for me is :
- Mechanical lockout (to prevent parasitic drain) requires removing the carrier, and each individual cell. This takes about a 1 minute. All of my other lights can be mechanically locked out in about 1 second by a single turn of the tailcap.
- The carrier is not designed to fit protected cells (I’m pretty sure it won’t fit them at all, at least according to the review on 1 lumen which say it fits cells up to 71.5mm in length). If a carrier is not designed to fit protected cells, and the carrier has parasitic drain and no low voltage protection, then that is just a major design flaw. Has the carrier’s lack of low voltage protection been fixed?
My Eagletac TX3V light has USB C charging and power bank capabilities. I don’t know if it has a high parasitic drain or not (have not tested it) and I don’t care, because Eagletac tells you in the instruction manual that if your not using the light for a while you should lock it out via a half turn of the tailcap to prevent discharging your battery. In addition to the extremely simple mechanical lockout, the light is designed to only fit protected cells (and they tell you to only use protected cells). So even if the light doesn’t have proper LVP, and you don’t mechanically lock it out, it doesn’t matter because the cell is protected. My Fenix LR35R is just like the Eagletac (except it doesn’t do power bank functionality) - it has easy lockout and it only fits protected cells. I have vaporizers that only take flat top cells (not protected) - just like the WT90, but the vaporizers have proper LVP so that they won’t kill your cells. Any device that is designed to only use flat top cells (unprotected), needs to have protection built in (an acceptable exception is when the device has an extremely simple mechanical lockout for storage, which most lights have).
The combination of these factors on the WT90 is just a major design failure:
- no mechanical lockout for the cells
- parasitic drain in the carrier
- no low voltage protection on the carrier
- does not fit protected cells
The result is a device that will easily kill your batteries if you put it down and forget about it for a while. Lets say I run it down to 3 volts and don’t check the charge and put it on a shelf for a few months … now my cells are dead! With any other light I own I would do a simple half turn of the tailcap before putting it down.
I also don’t buy any argument that its too difficult or expensive to implement USB-C charging and power bank functionality without introducing a high parasitic drain. I have a $20 Chinese power bank that doesn’t have parasitic drain, how expensive or difficult can the electronics be for this?
TA - You mentioned in reference to cheap power banks: WildTrail WT90 - SBT90.2 1800m+ throw 90mm 3x 21700 With Texas_Ace driver - #1244 by Texas_Ace
Cheap power banks do 2 amps these days and USB-C. Also, I would much rather have a light with 1 amp charging and no parasitic drain problem than a light with 2 amp charging and parasitic drain. Parasitic drain is more important than the charging speed when its in a light that doesn’t have mechanical lockout.
I’m not backing out on my purchase (should be shipping today). The light does more things right for its price than any other light in the same category. However, I would have loved to pay a little more to get a product that doesn’t have a major design flaw. All of it could be solved by better engineering on the battery carrier. If the lack of LVP on the battery carrier is solved, then that is a massive improvement .
I have the later production run with the reduced drain carrier, and the parasitic drain, while higher than other lights with USB type c charging, is reasonable, especially for 3P 21700s. To me, it’s worth it to have the polarity protection and type c charging and power bank. Plus, for what the WT90 is selling for these days, it’s a bargain (well under $200 US with a code).
Don’t have time to read/address all of that right now but I think you misunderstood when I said lockout. I was talking about a lockout to prevent inserting the cells backwards, not a lockout of power to the light.
The controller has to control the FET’s to disable a cell if it was inserted backwards which is a custom setup and why they can not easily swap to another setup as I understand it. They are not willing to remove the charging at this point so like I said the reduction in drain they came up with is about the best they can do without a complete redesign.
Putting the charging into the light body itself would solve these issues (and allow a mechanical lockout) but as I am sure I don’t have to explain, that would basically be an entirely new light.
I am not defending the charging or attacking it. I can see both sides and and basically neutral to it in the current state. They are doing the best they can given the design they laid out for themselves. The drain is low enough that it is still better then most lights on the market so that is good enough for me.
Personally I would of stuck to my original design and left the charging out of the design but they really wanted that.
Has the carrier’s lack of low voltage protection been fixed? (Tom E proved that it will kill your cells here: WildTrail WT90 - SBT90.2 1800m+ throw 90mm 3x 21700 With Texas_Ace driver - #1018 by Tom_E)
That is the biggest problem for me… The carrier should not kill cells.
You can remove the charging on the carrier and all those issues go away. It sounds like this would be the best option for you. If you can’t do it yourself I could do it for you.
I’m aware of the fix and its not a good fix for me because I want the charging. What I want is an answer about if this is fixed? By ‘this’ - I specifically mean the LVP in the carrier - will the carrier kill your cells if you leave them in there long enough?
Your post on August 21, 2021: WildTrail WT90 - SBT90.2 1800m+ throw 90mm 3x 21700 With Texas_Ace driver - #1277 by Texas_Ace
I read every post in this thread now and I do not believe you ever provided a definitive answer about if the LVP is fixed.
Side note : My order was supposed to ship today and I just got an email saying its delayed and is now expected to ship a month later :(. I ordered silver from Banggood, that is the only place that has a decent price right now ($185 with shipping and tax to United States).
I just checked my messages from wildtrail and the reason I never updated the thread about the LVP is it was never confirmed to me. They informed me they were working on it but I never got a confirmation it was working.
I just sent a message to try to get an update on that, I will update when I hear back.
Far as the banggood delays, can’t say I am surprised. I have heard they are having a lot of supply issues on the back end from covid still (or the lasting effects of the covid shutdown).
Just heard back on the LVP, it seems that they were not able to implement this due to how the IC is setup. If power is cut to the IC due to LVP, it will not be able to wake back up among other things.
Like I said they are using a pretty custom/advanced setup in order to handle the polarity protection (I think they repurposed a cell balance circuit for this purpose but not sure, hard to understand the translation of a translation lol) and USB charging combined.
Thank you for the update. I think at the very least we should update the instruction manual (and first post in this thread) about the flaws on the carrier (parasitic drain and lack of LVP). I had to spend many hours reading this thread to find out that my new light (when ever it ships lol) does the following things that are mentioned in no reviews (in fact the 1lumen review is wrong and needs to be fixed, I’m messaging Nick about it) and are very important things to know:
- The battery carrier has its own parasitic drain
- The light has no mechanical lockout to prevent parasitic drain (you must remove the cells)
- The battery carrier will kill your cells if you leave them in there for a long time because it has its own parasitic drain and it does not have low voltage protection (this light does not fit protected cells unless you use protected 18650s with an adapter). This will never be fixed by the manufacturer (they stated they cannot do it). This issue can be resolved by removing the USB charging circuitry (difficult mod for an inexperienced person, but people on this forum are willing to help if you want it and cannot do it yourself), but then you loose USB charging capability.
- There is an issue that causes the main LED to stay lit at an extremely low level that can only be seen in a very dark room. This issue is harmless as it has extremely low parasitic drain.
- The parasitic drain level of the entire light was around 2.27ma in the first production batches but that was fixed around August 2021 and the parasitic drain is now about 10x lower around 0.23 ma. I had to read many posts to acquire this information (no single post makes it easy to even confirm that this is indeed the correct parasitic drain level of new production units). Nick (Sirstinky on these forums) at 1lumen appears to be the only person to have measured the parasitic drain on the newer batches. It would be great if someone else could confirm these numbers. I don’t think anyone ever posted the math for the parasitic drain using the new numbers: 0.23 ma = ~6 years to drain fully charged cells. If this is correct, then the issue really is resolved. Its still very important to know that the carrier will kill your cells, but its going to take a long time if your starting off with fully charged cells.
Something I’m still not clear on: What type of low voltage protection does this light have? I have some Anduril lights but none with NarsilM - but I recall posts saying that Narsil does not have LVP? Nick’s review @ 1 lumen incorrectly says:
Nick also wrote on these forums:
So does this thing have some type of LVP? We have confirmed from the manufacturer that there is no LVP in the carrier…
Parasitic drain math:
2.27ma parasitic drain in the first production batches but that was fixed sometime August 2021 and the parasitic drain is now about 10x lower around 0.23 ma.
3x Molicel P42A cells: 4200 mAh x 3 cells = 12,600 mAh
drain before fix: 2.27 mA
12,600 mAh / 2.27 mA = 5,550 hours = 7.6 months to drain cells
drain after fix: 0.23 mA
12,600 mAh / 0.23 mA = 54,782 hours = 75 months = 6.2 years to drain cells
Yes, your math and conclusions are correct. You are looking at many years to drain the cells at the current parasitic drain level. This also means many years to kill the cells, in which case if you leave the cells in the light for 4-5 years+ without checking on it, I can’t say that is unreasonable considering most e-switch lights out there will kill the cells faster then that and also do not have LVP.
Narsil does indeed have LVP, pretty sure it is using basically the same setup an anduril, they share a lot of code last I checked.
So what I’m getting from this is that the flashlight has LVP and will cease operation when a preset voltage is hit. However, this does nothing to stop the parasitic drain from the carrier which will continue to drain the batteries past the LVP voltage floor. But the parasitic drain is so small that this should only be a problem if you run the flashlight until LVP kicks in and then leave the batteries in the light uncharged for a LONG time. Plus, it’s ill-advised to run a light till LVP kicks in and then not charge the batteries because self-discharge will eventually bring the batteries below their voltage floor anyway.
P.S. They still sell this for $150 anywhere? By the time I finally made up my mind I missed all the sales haha
Yeah pretty much this.
Don’t know of any deals for $150, think that was just a holiday sale.
A problem I have found with the battery carrier…
The brass positive posts have sharp edges, and when pulling out the first battery my fingers were not able to pull it all the way out, so the edge of the battery snagged on the brass post.
The brass post sliced into the wrapper over the top edge of the battery and shorted the + and - terminals through the battery I was pulling out. The wrapper burned and smoke started immediately. (The other two batteries were shorted thanks to the battery I was taking out)
I’m a little nervous about this battery carrier now…
I am using samsung 40T cells, and they do seem to not want to come out, the post snags on the battery wrapper around the + terminal.
Thanks for the heads-up, I will be more careful now with the carrier, and may sand off the sharp edges. Btw, what I do with all my batteries nowadays is adding an extra wrapper so that they handle moving them around a bit better, with the extra advantage that I can colourcode/mark matched batteries for multibattery flashlights.