Olight SR-91 Review with OTF Lumens and runtimes

The Olight SR-91 is a new light that's being introduced into the SR series of lights by Olight. This light was designed to be smaller, and to have an increased runtime over its big brother, the SR-90. I've performed OTF lumens testing and an 84 minute runtime test on this light, as well as included some eye candy :naughty:.



Specifications (taken from Olight's website):

Luminus SST-90 LED, 30W, lifetime 60,000 hours.

Output & Runtime (manufacturers ratings):
Two brightness levels and strobe mode

1). High Mode: 1500 Lumens / 3.1 Hours
2). Low Mode: 450 Lumens / 10.5 Hours
3). Strobe: 10 Hz / 6.2 Hours

Max throw: 800 meters.
Battery pack: 6 x18650 (7.2v, 6.6A)
Dimensions: Length: 288mm (13.23") Bezel Diameter: 80mm(3.15");
Weight: 1196g (With battery pack)

Accessories: Includes one strap, one charger, one operator's manual, one O-ring, car charger(optional)

Features:

Rechargeable battery pack with built-in 6x18650 batteries (7.2v, 6.6A). Rechargeable socket on the tail
Super bright, modern and novelty design.
Super Strong anti-Reflect coating lens，99% effective transmission
Four indicators on the tail for indicating the batteries condition:

1). 1 indicator on: 20% -40% power remains
2). 2 indicators on: 40% -60% power remains
3). 3 indicators on: 60% -80% power remains
4). 4 indicators on: 85%+ power remains
5). No indicators on means batteries with less than 20% power remains and need charging

Excellent tridimensional heat dissipation ability
Easy touching switch on the head for turning on/off the light and transfering modes.
Special designed charger, Removable and adjustable strap.
Two charging methods:

1). With the whole torch,
2). Only the battery tube

Mil-spec: MIL-STD-810F
Highly water resistant to IPX-8
Anti-shattering ultra clear lens, anti-scratching, anti-slip function.
Tough and rugged body offering firm grip
Advanced digital power management system

Operation:
Press the side button switch to turn the light on.
Press and hold the switch to transfer the output from high to low. A fast double press will active the 10Hz strobe




Now it's time for some OTF lumens :

OTF Readings taken in my homemade IS:
Here are OTF lumen readings of this light. I have a homemade 16" (like MrGman had), but I recently built a 24" integrating sphere like Bigchelis has. I recently built the 24" sphere so I can measure these new monster lights that are being produced. MrGman was kind enough to share his time and knowledge helping me get both of these sphere's set up and accurately calibrated. I'd like to take this moment to thank him for all of his help; without him, this wouldn't be possible. Thanks MrGman :thumbsup:


These numbers are as close as you can get with a homemade system like this, but keep in mind that these numbers are what you can expect to see. What I mean is, different variables can cause one light to be brighter than another one, so keep in mind that it's possible for you to purchase one that's not as bright as this one, or one that's brighter than this one. Anyway, enough talking. Here are the numbers:

High Mode:



Low Mode:






Now for the runtime graph:
I will note that this thing gets pretty darn hot when ran on high for this length of time. The head of this light got so hot during the runtime testing that I couldn't hold my hand on the shoulder of the head for longer than three or four seconds. I'm not sure how hot that is, but I'd say pretty toasty. The runtime graph is with the light fully charged and in high mode, and as you can see, the light just shuts off at the end of the runtime. I doesn't turn back on until you plug the charger into the light.









Now it's time for some eye candy :naughty::

















Battery level indicator:







The business end : (Also, notice how clear the glass is? I've got to give it to Olight; they've got some pretty clear glass.







The next two images were also taken with the glass in place. Did I mention how clear the glass is?




If you're interested in purchasing one of these lights, click here.

84 minutes before batteries were dead???? Yet it says 3.1 hours?

I wonder if you did the test in say 5 min increments could it have an on time of 3.1 hours, maybe the heat buildup creates a need for a ton of extra juice to keep it running?

Nice review Ti, you sure are right about that glass it's very clear indeed.

It uses the same battery pack as the SR90 and the SR90 runtimes I have seen is around ~82 minutes so one would think you would at least get a couple hours with this one.

So the question is what is the missing factor?

I don't know. I must say I was surprised myself when it shut off at 84 minutes. My first thought was that the light had a thermistor, or something to shut the light off to keep it from overheating. I let the light sit for about 30 minutes after it cut off and I tried to turn it back on and got nothing. Then I started thinking that I might have toasted this light ..., but as soon as I plugged the charging cord into the back of it, it turned right on. Its still charging as I type this, and its been on the charger for at least a couple of hours now. If you look at this post, which is BigC's readings for the SR-90, you will see that the SR-90 is almost down to the same OTF lumens as the SR-91 at 5 minutes.

Let us know if you do another runtime I have been seriously considering this light. Thanks

jhc37013 said:

Let us know if you do another runtime I have been seriously considering this light. Thanks

Click to expand...

I think I was editing my previous post while you were posting so I don't know if you saw it or not, but take a look at this post by BigC. Notice how the SR-90 is almost down to the same OTF lumens as the SR-91 at 5 minutes? I may be wrong, but I don't think it's going to get any better.

I know that Olight says the SR-90 and SR-91 are driven hard or at full power.


but


What are they driven at? 5A? 6?:thinking:

bigchelis said:

I know that Olight says the SR-90 and SR-91 are driven hard or at full power.


but


What are they driven at? 5A? 6?:thinking:

Click to expand...

That's what I'm thinking.

I have an SR-90 and I can confirm it has 1500 OTF lumens with 1 hour ten minutes runtime.

Your lumens reading is higher than expected; may be your SR-91 has, mistakenly, the "guts" of an SR-90.

Regards,

Anthony

I've been interested in this light and waiting for a review - thanks for all your work with the reviews.

OTF seems about what I expected but runtime is way too short vs manufacturer specs :thinking:

I had hoped for a seriously long running dog walking light that can light up the trails for 3 hours. Seems this is not the case.

My understanding was that all components were the same with the SR90 but the SR91 was not driven as hard - hence lower OTF - and smaller head because less heat sinking was required but 'almost' triple the run time on high?

So essentially when I bought my SR90 it was for the runtime and not the superior brightness?

I have been suckered by marketing.. yet again :shakehead

Pissed of and fedup. I suppose, the only consolation I have is that I purchased the SR90 when the SR91 was non-existant.

wantsusa said:

84 minutes before batteries were dead???? Yet it says 3.1 hours?

I wonder if you did the test in say 5 min increments could it have an on time of 3.1 hours, maybe the heat buildup creates a need for a ton of extra juice to keep it running?

Click to expand...

Yes, I also wonder. And <1300 OTF lumens does mean it's not much more than 2 times brighter than Fenix TK30, and for around the same runtime...
I thought that the difference should be much bigger! :thinking:
Does this mean that SR50 claimed for 800lm has practically the same brightness as TK30/40? And what is the true runtime when it's stated at 1,5 hours? Something seems to be wrong here!

I don't know guys, maybe I do have an overachiever in the OTF lumens department, which would certainly result in an underachieving runtime.

Anybody have lux readings?

Thanks ti-Force for the excellent review!:thumbsup:

Don't quite know what to make of the short runtime. I'm thinking either a defective unit or worse, false advertising.

The light not coming back on at all after the batteries drained is normal for these types of lights? I would expect that it would light up a bit and then die out again?

Pandorum said:

Thanks ti-Force for the excellent review!:thumbsup:

Don't quite know what to make of the short runtime. I'm thinking either a defective unit or worse, false advertising.

The light not coming back on at all after the batteries drained is normal for these types of lights? I would expect that it would light up a bit and then die out again?

Click to expand...

Thanks for the kind words, and you're welcome I'm not sure about the runtime either, but I'll see what I can find out. Also, something else I'd like to mention is that, like the SR-90, the battery gauge doesn't appear to be accurate while the light is turned on; I checked it about 25 to 30 minutes into the runtime and it only flickered a few times, and in about 10 more minutes it wouldn't come on at all.

Well I see some newer posts were lost but anyway

I was thinking, since the SR91 and SR90 both use the same battery pack, and reviews of the SR90 has shown expected normal runtimes, then your results must be due to a defect in the unit somewhere. Since you got higher than expected light brightness in your test, it could be running brighter than it was designed which may explain the short runtime and even the hot temp of the light.

Well, at the request of ti-force I went ahead and broke my record thus far and did a runtime test. I have absolutely no information about the output curve, but I can confirm that the runtime he measured was in the same vicinity. I'll have to update my review with this new information.

My runtime measurement was 1:20:14.

Really excellent pictures there, by the way. Excellent review.

AardvarkSagus said:

Well, at the request of ti-force I went ahead and broke my record thus far and did a runtime test. I have absolutely no information about the output curve, but I can confirm that the runtime he measured was in the same vicinity. I'll have to update my review with this new information.

My runtime measurement was 1:20:14.

Really excellent pictures there, by the way. Excellent review.

Click to expand...

Thanks for the complement, and thank you very much for taking the time to do runtime testing. You've confirmed that mine isn't defective, and with a runtime of roughly 1.33 hrs (1hr 20 min), and with 47.52Wh of battery power (7.2v x 6.6 = 47.52), we can do this: 47.52 / 1.33 = 35.73 watts power draw from the battery, then 35.73 x .9(90% driver efficiency) = 32.16 watts at emitter (roughly) .

ti-force said:

Thanks for the complement, and thank you very much for taking the time to do runtime testing. You've confirmed that mine isn't defective, and with a runtime of roughly 1.33 hrs (1hr 20 min), and with 47.52Wh of battery power (7.2v x 6.6 = 47.52), we can do this: 47.52 / 1.33 = 35.73 watts power draw from the battery, then 35.73 x .9(90% driver efficiency) = 32.16 watts at emitter (roughly) .

Click to expand...

So if yours isn't defective, I've basically bought a SR90 for only 1 reason - a bigger piece of conical metal - the reflector.

Well, I guess I can forgive them since the SR91 didn't exist at the time.

But what great marketing by Olight.