Review: Trustfire F22

About 1hr 35 min to 50% on an alkaline on medium. Again, will let it run down to cell death since it isn't a rechargeable cell. Graph to follow when the cell finally dies.

Just messed up the medium runtime. Saved it in an unusable format. Low runtime now running. 45 lux - about 10 lumens at start on an alkaline. This is at Fenix E01 levels. Should run for ages. Fan cooled - which is almost certainly unnecessary.

Nice man.......What light meter do you use......and what program do use as well for graphs and runtimes.

The meter is a cheap one from DX. http://www.dealextreme.com/details.dx/sku.20170 though the runtimes are done using a solar cell built into the lightbox which is a medium sized cardboard box painted white internally with 4 coats of gloss paint and a baffle to prevent any direct light from the torch hitting the solar cell or meter. I use a cheap USB connected multimeter that I got locally http://www.maplin.co.uk/Module.aspx?moduleno=222041. It is probably available under dozens of different brand names around the world. I got this on offer for about half of what they used to ask for it.

I use the software that comes with it which is not wonderful, but is usable. I just feed the data into a spreadsheet to produce the graphs, copy and paste the graphs into a graphics app to save them as jpegs. But I have to remember to save the data as a spreadsheet - the native DB format isn't understood by anything and the software can't open the files either - it appears to be some sort of binary format which is a pain.

I am beginning to wonder about the linearity of the response of the solar cell but that will take a lot of time and effort to sort out and calibrate properly.

I get the approximate lumens figures from a Preon 2 which is 160 lumens out the front according to several sources. It read 720 lux on my lightbox so I take a lux reading of whatever I'm measuring, divide it by 720 and multiply it by 160 to get an approximate lumen count.

Okay thanks for the input...dont know if i want to go there yet, but thanks for posting the info for me.

Now approaching 50% after nine hours. Unfortunately I'm going to have to sacrifice another alkaline to get the medium runtime graph. It runs for a little over 90 minutes to 50% on medium with an alkaline. NiMH and 14500 runtimes to follow in due course.

Still better than 50% at 11.5 hours when I left for work.

That's very impressive! You might just convince me to buy this light if you get 24+ hours of usable light.

It did the first 12 hours fine, but I don't expect it to do 24. We'll see though

Gave me 2hr 15min of usable light on an alkaline in medium and around 16hr on low. The alkalines were all cheapos though most weigh 22-24g. A Duracell weighs 24.6g. Weight is a reasonable proxy for quality in alkalines. The lightest one, a Rayovac that did one of these runtimes was 22.4g

Next up NiMH runtimes. Time to top off some cells to make sure they are fully charged.

Starts out on an NiMH at the same sort of brightness as an alkaline on high - a hair over 85 lumens.

NiMH low. Down to 39 lux or about 8.6 lumens. Looks like NiMH runtimes will be comparable to alkaline ones but it'll take some time yet to be certain. I expect the light to go out tomorrow about noon.

9hr 13 min to 50% on low with an NiMH. Graphs for NiMH high and low added, NiMH medium and 14500 graphs next.

39 min 15 secs to shutoff - it was still pumping out over 150 lumens when the cell protection kicked in rather early I suspect. Initial brightness around 220 lumens.

Pretty good runtimes overall. What capacity are nimh cells used.

2,000mAh Eneloops. Might try it with some of the "2700"mAh cells I have somewhere. If they will still take a charge.

Cool......the only 2700mah cells i have are the Powerex cells. I sent them an email yesterday about the capacity going down hill and the person was telling me to do a break-in on the cells when i already have done 3, the person also sent me another email asking me for my addy so he can send me brand new 2700's. CS also didnt say about sending the cells back- Gotta love Maha CS. I was thinking with a fresh high mah cell that the runtime would be more. Im glad your on this forum, just too bad you dont live closer so i can mail you some lights for you to test out.

I suspect the cell I used - a blue protected "900mAh" Trustfire has a rather too sensitive low voltage cut off. The light was still putting out over 150 lumens when the cell protection cut in. Runtime to 50% 39 minutes 15 seconds. About a second after that, it had shut off.

Starts at 110 or thereabouts lumens - more than the NiMH or alkaline managed on high. If it gets past 65 minutes on medium it is managing more light for longer than the NiMH or alkaline cells could manage on high. Brightness and runtime are a tradeoff. This is using the same cell that ran for 39 minutes on high. If I'm still awake when it finishes, I'll check the voltage it cuts off at.

I wonder why that is.....i guess the light likes lithium chemistry over the others.

Pretty respectable runtime on NiMH to 50%. It is still 20 or so lumens at 50% or pretty much what Luxeon I LEDs in a small body could do on a good day. Plenty of LED lights could do better - this one appears to be optimised for 14500 use. Lots and lot of light, just not for a long time. If you want 20 lumens for ever there are better choices. If you want 200 lumens there aren't as many choices. But realistically if you want 200 or more lumens for a long time, you don't want to be using 14 x 50mm cells to get it. Nor do you want to be using a stainless steel body - not until LEDs and drivers are way more efficient. The best LEDs can do about 120 lumens per watt under lab conditions - in the real world 60 lumens per watt is probably nearer it. The theoretical maximum is something over 400 lumens/watt.

Not any time soon.....

Thanks for the details here Don! Great reporting. I wonder why the NiMH didn't give very good runtime on low? Was the battery well charged?