PT EOS run time

[darklord]

The PT Eos looks like the headlamp for me. However, I'm confused by runtimes.

The PT site states 1hr regulated and totalburn time 113hrs on HIGH. 10hrs regulated and totalburn time 115hrs on MEDIUM.

The flashlightreview review (!) states HIGH - 2 + 4.5hrs, MEDIUM 9.5 + 3.

Rather large differences!!

OK, flashlight review was back in 2004 and things will have moved on...but by that much?

I'm not convinced by PT's 'totalburn time' figures, and wondered if anyone had any experience? A 10hr regulated light on mediun sounds pretty amazing off 3 x AAA. Especially if it goes on usefully for a number of hours after that.

Any real life Eos advice?....or some testers confirmation figures?

thx.

 

[Woods Walker]

The PT Eos looks like the headlamp for me. However, I'm confused by runtimes.

The PT site states 1hr regulated and totalburn time 113hrs on HIGH. 10hrs regulated and totalburn time 115hrs on MEDIUM.

The flashlightreview review (!) states HIGH - 2 + 4.5hrs, MEDIUM 9.5 + 3.

Rather large differences!!

OK, flashlight review was back in 2004 and things will have moved on...but by that much?

I'm not convinced by PT's 'totalburn time' figures, and wondered if anyone had any experience? A 10hr regulated light on mediun sounds pretty amazing off 3 x AAA. Especially if it goes on usefully for a number of hours after that.

Any real life Eos advice?....or some testers confirmation figures?

thx.

I get around 1.5-2 hours regulated on high with 900 mAh NiMH batteries. Around 11-13ish on medium and unknown on low as it is just soooooo long. The EOS is one of the few headlamps with a true low mode. This is based on what I can see and don't have a charts etc. Once the light falls out of regulation I toss in new batteries as being 3XAAA I can't recharge them all at once in my cheap USB charger so I don't want the cells to back charge and vent. Also from what I have read the runtime on lithiums are mostly regulated with much less direct drive so maybe the 4-6 hour numbers on high being talked about are for lithiums. Don't know.

 

[likeguymontag]

It depends a lot on the chemistry of the batteries that you use. Forget their web site; they have a much better runtimes table in the manual. Unfortunately said manual comes with the headlamp, so you can't see it until you've already paid for it. I'll transcribe it:

EOS runtime (hours regulated, total)

Alkaline:

High: 113, 113
Medium: 10, 115
Low: 50, 121
Flashing: 3, 100
​

Lithium:

High: 6, 8
Medium: 17, 20
Low: 55, 60
Flashing: 10, 24
​

Note that there's an obvious error in the table; I highlighted it in red. The runtime on alkalines on high is about one hour. NiMH chemistry will be more similar to lithiums than alkalines because NiMH cells can handle the high current of high mode. With NiMH you'd probably get 2/3 the runtime of lithium cells, but with the same ratio of high/med/low runtimes. Other people have done actual tests with different NiMH cells in the Eos, perhaps someone would be so kind as to dig up a link.

As for the disparity with FlashlightReviews? He uses a different standard than PT for when a light is considered dead. PT considers total runtime to be until the unit is only producing as much light as a full moon; 0.25 lux at 2m.

 

[darklord]

Thanks for the information, guys, interesting stuff.

It's always difficult to euqate manufacturer's runtimes with real life situations, and of course everyone's real life situations are subtly (or not so subtly!) different, I guess.

WoodsWalker, 11-13 hours on medium sounds excellent - is it a useable beam? (again, the throw looks good on the PT site, but for real?...). I'm also interested to know what you mean by a "true low mode".


Likeguy, thanks for the info. on the cell chemistry, I can see that that might make a difference. Here at home with charging on tap I'd be using NiMH, but I also need a light for expedition (caving) use where there are no charging facilities, so that means carrying in alkalines (or lithiums). I've used a Myo XP in the past, but we had several problems: lithiums completely broke one unit (we didn't know about the warning at the time), and two other units failed in various ways, possibly due to corrosion from the high humidity in the jungle. Not that they weren't good, but maybe there's something better now? I favour the AAA format because every ounce saved in weight is immeasurably important when trekking deep into caves for several days at a time. Also the EOS's waterproof format might keep the humidity at bay.

Thanks for the info, guys.

 

[Woods Walker]

The med is good enough for most of my trail work. The low is low enough for camp without back glare and power drain from too much light. Many headlamps and flashlights for that matter don't have a proper low. Use NiMH for better runtimes on high/med. On low it should be the same with most batteries I think. Less drain.