User review Fenix BT20

[xcracer450]

Well, that's a bummer. Can you recommend something around the same price range with similar capabilities? No thread jack intended (please message me)

[socal_jack]

A pointless test for most people I would think as I doubt they would hack their gear up unless they also got it free. Note that there is a 4 AA-cell battery holder available on their site for this also.

Fenix should of included some cells for this test, but I assume they wanted to find out how other batteries will hold up to this light. Unfortunately I do not have any quality 18650 cells. I do plan on purchasing some in the near future, but for this test all I have are the cheap DX cells.

I may have found a solution to my crappy cells. Don't know if this is what Fenix wanted, but I'm going a head anyways.

Up next testing the 3 cell pack, but not tonight.

[pucked up]

Okay so I took the BT20 out for it's first ride tonight. First impression are:

On the Handle Bars:
Pros:
1 - Quick to mount/un-mount both the battery pack and light head.
2 - Light head adjustable 360 degrees.
3 - Compact does not take a lot of room.
4 - Awesome light output both flood and throw.
5 - O-rings kept light head firm to the bars.
6 - I love the flood pattern from this light!

Cons:
1 - No remote switch.
2 - Light output could be brighter.
3 - Need high quality 18650's which is not included.
4 - As with the batteries, charger not included also.

Riding with the Fenix BT20 on my handle bars out on the trails is awesome as I assume it would be. There is a wide flood light in front of the bike and a good beam throwing the light out on to the trail. The flood pattern is wide enough to cover the width of most trails and extends about 4ft out. A narrower beam pushes the light out from that point on.

Having only one light source is not enough to really attack your favorite trail and I wished that more light was available from the BT20. I would recommend a good helmet light to be used with the BT20. A combination of a good spot helmet light and the BT20's beam pattern would be a killer combo on any trail. This would be my set up of choice when going out at night.

Fenix hit the bulls eye when it comes to the LED tint. To compare it, I have from Ledsupply a Neutral and Cool White LED for my light builds. The LED that Fenix uses falls in-between the ones I bought. It's brighter than the Neutral, but still illuminates a natural look on to the trail not washing it out like Cool LED tints tend to do. Hopefully if you do use a second light with the BT20 the light tints match up. My second light didn't match up, but it was not a big issue for me. Or you can just purchase two BT20s!

What makes this light great is that you can rotate the light head 360 degrees. This means that you can center the light out on to the trail by adjusting it side to side. As most of us will have the lights mounted off center on the handle bars.

On the Helmet:
Pros:
1 - Light weight.
2 - Both the helmet strap and light quick to mount.
3 - Great light output.
4 - O-rings kept the light firm to the helmet strap.

Cons:
1 - No remote switch.
2 - Light output could be brighter.
3 - Need high quality 18650's which is not included.
4 - As with the batteries, charger not included also.
5 - The flood pattern.
6 - Height of the BT20 on the helmet strap is too HIGH!!
7 - Extension cable is too short!

Riding with the BT20 on my helmet was not as exciting as on the handle bars. It's not bad, it's just different. With my helmet lights I'm use to a tight / spot beam pattern. The BT20 I notice more of a flood than what I'm use to. Maybe it'll take me some time to get use to it, but this would not be my first choice as a helmet light.

My experience is like driving you car at night on a straight roadway. You then turn your head from side to side and have you headlights follow your head as your turn it. I'm use to having my flood light stay straight ahead of me and having my spot light scan a head of me. Having a second flood light may reduce this weird sensation, but you'll still need a good spot/tight light. I was surprise that the lights I've build with a tight optics throws a litter better than the BT20.

I would say that the BT20 makes a better handle bar light than a helmet light.

Final Words:
Fenix BT20 is a great product. The light head and components that comes with it is well made and of quality. The dual beam pattern is surprisingly well accomplished. The tint of the light is perfect for the trails and on the road. This makes a great Christmas gift for any mountain biker who like to ride at night!

Some items Fenix should work on are, extension cable, it's too short! It should be at the 1 meter mark like other companies. Also the cable is too stiff and made it shorter as the bends didn't straighten out.

The helmet mount is too high, it can be cut down a bit by having a semi circle mount instead of a full circle.

Should recommend high quality name brand batteries instead of just stating what type to use (if not using the ones from Fenix). Also have an option for a four 18650 battery case.

Finally, having a remote switch for the BT20 would make it more attractive as you will not need to remove your hands form the handle bars (when mounted on the bars) when cycling through. Also helps when using the BT20 as a helmet light as it's higher than most other lights.

[pucked up]

A pointless test for most people I would think as I doubt they would hack their gear up unless they also got it free. Note that there is a 4 AA-cell battery holder available on their site for this also.

Yes, I know, but I really only hack the extension cable.

[socal_jack]

Well the rest of the review was pretty good. I noticed on their page that they do offer it with Tenergy batteries etc for $129 (says they're out of Fenix branded batteries)

Yes, I know, but I really only hack the extension cable.

[spankone]

I bought the Fenix bt20 about a week and a half ago and just received this email:

"It is with great regret that we received an email from Fenix (the manufacturer) last night asking that we NOT ship the BT20 lights we had just gotten in and had already starting processing for shipping. Apparently, there is a slight issue with the light that causes the "low battery indicator" to come on when in Turbo Mode after just a few minutes. We are told this does not affect illumination or run time so I'm sure Fenix will resolve this issue quickly. In the meantime, we are going to refund your purchase price. If you paid by PayPal, your refund should show up quickly. If you paid by credit card, it takes 2-3 days for a credit to appear on your statement.

We do apologize and hope you will re-order once Fenix has resolved this issue. "

I've noticed on my sample that on turbo it instantly goes to red. IMHO I would wait until they fix it.

I also made it on to the testing list I hope you don't mind if I jump in on this thread.

Here's a link to my video review.

http://youtu.be/4InVN0jgatw





































Now my first impressions are good I would certainly recommend using it as a bar light. Although the flash modes aren't really suited for commuting. I think a 750Lumen flash-strobe mode would soon get you run off the road. But the beam pattern is useful on the bars the modes are we spaced and run times seem good.


But has a helmet light it's very much a different story. The strap and mounting is solid but it sits way to high. With both light and battery fitted to the helmet it's way to heavy. And if used on its own as a helmet light you get a very distracting secondary halo. This halo is visible on the bars but its not distracting. On your helmet it gives you a very odd tunnel vision effect.

What I highly recommend is that fenix produce a third light to the range specifically for helmet mounting a 1x18650 using the new xp-g2 with the option of plugging an optional secondary 18650 for extended run times.

So I've used it in the woods I'll be hitting the road with it tonight. and by next Wednesday / Thursday I'll add the second part to my video review.




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[Cat-man-do]

That's what I was thinking. I'm guessing you'll need 3 cells minimum and I may have something that I can use for this light.

I was told by Fenix that the max voltage for this light is 12V. I'll keep you guys updated.

.

This might be why the auto-power down feature is not working as planned. It could be the driver was designed with too wide a voltage input range and the power kick-back settings are adjusted for the potential larger voltage. If the 3-cell set-up eliminates the quick indicator switch over than I am correct in my assumption.

If I'm right, Fenix will either need a new driver with a 8.4 volt max input or design the driver with a manual switch so that the user can set the driver for the right input voltage level.

It figures a torch manufacture would do something like this because many torches are designed the same way. Need I say, I've never been fan of torches ( or drop-ins ) that use the wider voltage range on their drivers. That's because when you power these drivers with a lower voltage battery ( say with a single cell 4.2volt peak 18650 ) but the driver can handle a 8.2 volt battery, there is always a significant drop in output once the single cell starts to discharge. This is why when I recommend torches or drop-in's I always tell people to get the ones with a max input of 4.2 volts ( if they are going to use a single cell 18650 lamp ).

[spankone]

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[Wolfsburgfan]

I want one, the throw looks nice. Should I wait now given the problem?

[Wolfsburgfan]

Any other light in this price range that I should look at? I want it mainly as a second light.

[pucked up]

I also made it on to the testing list I hope you don't mind if I jump in on this thread.

Not at all. You're welcome to post your result here.

It you have high quality name brand 18650s try and do the run time test on Turbo. I tried but my batteries were not up to par for the test.

If the 3-cell set-up eliminates the quick indicator switch over than I am correct in my assumption.

Well, you're correct. I ran a test on Turbo mode with the 3 cell pack last night and the light indicator did not switch to red after 2-3mins. But after about 40mins it drop to High mode with the indicator still green. I had a fan blowing on it on high, it was warmish at best, so it's either that the heat protection kicked in or there is not enough juice with the batteries I used.


Testing HIgh mode with the original 2 cell battery pack the BT20 came with. I'll post an update later.

Update: The test on HIgh mode lasted for only 2.5hrs then drop to Low mode and could no longer cycle to the other modes. The battery indicator light turned red after 40mins while on High mode. But Fenix did admit that they have an issue with the indicator light and I also wonder if they have and issue with the driver they used as Cat has said above.

[Vancbiker]

I have a hard time understanding how the battery voltage sensing would work right at all if you raise the input voltage to 12.6 using a 3S battery. The end of useful charge in that battery will be ~9V. That's higher than the starting voltage 8.4V of the original pack. I'm guessing the driver is programmed to change the indicator color or light output at set values. Maybe it senses the voltage when first turned on and that selects values based on the starting voltage. Anyone help me get this?

[spankone]

I'm running Panasonic 3100mah cells. I'll make sure they are full juiced up before I head out tonight. I've got a nice road ride planned.

Have noticed that it flash between red and green. Which stops if you knock it down a mode. Then holds green again.

The build really is good. The front is aluminium and the black fins. But the rear half is plastic. Which isn't a big deal tbh it's hard to tell its plastic.


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[MirosPikos]

"But the rear half is plastic. Which isn't a big deal tbh it's hard to tell its plastic."

It is only plastic because of cover the heated body of light, I think so...

[spankone]

Yeh I think your right. The plastic cover goes over the heat sink.


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[spankone]

Ok geeks My Panasonic cells measured 4.20v this morning at 9am when I left for work. 8 hours later after being left plugged into the light head both cells measure 4.18volts.

So both batteries dropped 0.02 volts over 8hrs. Is that acceptable levels of parasitic ?


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[mattthemuppet]

unless you do the same test without them being plugged into the light, it's impossible to know if this is normal for your cells or due to the light. Then, if it is due to the light, you'd have to trickle charge them back up to 4.2V on a hobby charger to measure how much capacity has been used. My guess is very little - a drop from 4.2 to ~4.1V equates to about 250mAh capacity, so a 1/5th of that drop is likely to be pretty small.

[spankone]

It's not normal for my cells I often leave them for a week and test them.


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[betweenrides]

Ah, too bad. Not ready for prime time, eh? Fenix missed the night riding season for me anyway. Looks like a nice quality product but with some niggling design flaws. I am surprised by some of the documentation omissions. They should disclose type of battery to use (protected or not) and minimum mAh.

[spankone]

After doing some more tests, battery drain is not noticeable. May be I was wrong and the drop was just due to my cells relaxing after being removed from the charger.

Im glad I'm wrong


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[pucked up]

Update

I have to correct myself on the Turbo Test I completed in the past. I don't know if Fenix has an issue with Turbo mode, I've search the web to see if anyone else posted review but didn't find any.

Anyways ran the test with 2 cells fully charge. Battery indicator went red within the first two mins. and then drop to High mode after 5 mins. Ran the test a second time with the same results.

To see if it was my batteries, I ran the test again using 3 cells. This time the battery indicator stayed green but drop to High mode after 5 mins also. If this was a heat issue, I had two fans on high blowing on it. The BT20 was barely warm to the touch. Ran this test a second time with the same results. I figure I would get more than 5 mins with 3 cells on Turbo but didn't.

If anyone else testing this light having this issue, it would be nice to know I'm not the only one.

I've emailed Fenix to see if anyone else experienced this issue. Waiting to hear back.

[spankone]

In turbo I find the light goes red instantly. But doesn't drop out of turbo mode. Fenix have told me theirs an issue and have told their distributors to hold fire on delivering them.

I'be found the fuel light in high goes from green to flashing red/green. The constant red. I've not drained the cells enough to see the next stage.




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[pucked up]

In turbo I find the light goes red instantly. But doesn't drop out of turbo mode.

Spankone, so you're able to maintain Turbo mode for longer than 5 mins?

[spankone]

Yep.


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[pucked up]

Yep.


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Thanks, so must be my batteries not enough amps in them for this light on Turbo mode. Being that this is the only brand of batteries I have, my testing may have come to an end.