I think Dinottes still use AAs in packs. But since 18650s have apparently been standard in laptops for years now (I had no idea they're what laptop and camcorder packs were made of), I wouldn't be surprised to see them more commonly used in high-end lights.

I've used overvolted mr11&16s for commuting for years, I find them more than adequate. Main problem is efficiency and resulting battery requirement.

I've never used 2x20w lamps because it's overkill for my needs, plus would have too little runtime with the batteries I own.

A mr16 is in fact much brighter than the same (20w) rated mr11. You would know this to be true in a second if you had ever actually compared them. This is the main reason why DIYers use mr16. MR11s aren't as bright, they're hard to find, and significantly more expensive.

I don't see how you could be using 2x20w mr16s, overvolted, and have the resulting illumination pale in comparison to an inexpensive p7 flashlight.

I sincerely hope I'm wrong, since I'm all for inexpensive bicycle safety enhancements. Either leds have taken huge leaps in the last year, or you have some crummy mr lights.

I don't read this forum regularly; I'm not obsessed with bike lights. If you have beamshots comparing 2x20w mr lights to a p7 emitter, then please kindly post them or direct me to them by link so that I might evaluate them myself.

BTW, MR16 bulbs cost 2 bucks at lowes - lifespan, cost - it's trivial. 500hrs=5000miles.

I've used the website below occasionally for ideas, and have based decisions and comments on the data presented there. It may be inaccurate. If you have better information, please share it.

https://nordicgroup.us/s78/

https://nordicgroup.us/s78/wattslumens.html

Now that's getting personal. You may ignore my post, or this thread if want to.

Lumens, no. Lux, yes. The bulbs are the same. The larger reflector of a mr16 is better at capturing the light and focusing it then a mr11, hence higher lux. A mr11 has more leakage of light then a mr16.

LEDS have taken huge leaps in the last 2 years.

That site is outdated and the information is inaccurate. First, According to their own source, halogens emit 18-22 lumens per watt. Which is very different from the numbers they list. Second, even a wiki search shows it to be otherwise. Luminous Efficacy. Also check a physics textbook and they show different numbers. Third, according to the lighting research center,

Lumen output:

Most lamp manufacturers do not publish lumen output ratings for MR16 lamps or other reflectorized lamps in their catalogs. Instead, they publish beam angle and CBCP, which provide more accurate information about the performance characteristics of the lamp. NLPIP tested several 50-watt MR16 samples of the same type (EXN) to determine their lumen output, which ranged between 560 lumens to 710 lumens, and averaged 625 lumens.


Now that's for a 50W halogen, imagine what 20W halogen would be rated at (averaged 250 lumens).

For accurate information check this site. It contains a wealth of information on lights including leds, halogen, incans, h.i.d., etc.

I think we've got to take people's visual observations at their words. No matter how good a light 'should be' on paper, all that really matters is what you see in front of you. I'll take a first hand account over a theoretical one any day when it comes to this stuff.

Is there a specific reason that the 8-mode is so often recommended here? It's out of stock so I was thinking about getting this one that has 5 modes.

Probably because the 8-mode model has higher ratings at DX, it claims to be regulated unlike the 5 mode model, and has a copper heatsink. Though, both models are fine.

Also the mode sequence are different. For the 8 mode, it's "Mid > Hi > Rapid Strobe > Low > 3Hz Strobe (Alert Mode) > 1Hz Strobe (Alert Mode) > SOS > Special Tactical Police Style Strobe". For the 5 mode, it's "Lo > Mid > Hi > Strobe > SOS". It might be preferable to start with the mid mode instead of the low mode (which may be too low).

Is there a good option with two AA batteris. I have tons of them and prefer
to not get another charger and start another battery collection.

I do two have a Fenix L2D Premium Q5 . My issue is that the 180 lumens is in the strobe mode and the 100 is in the steady. I love the strobe for people to see me, but a steady light will help see the road better.

Thanks

You are mistaken, it's also 180 lumens steady in 'turbo' mode.

How is the throw on the DX 8 mode p7?

Most P7 flashlights are more floody which is ideal for bike riding.. If you want great throw look at the Fenix TK11 - Q5 light..

What are 18650s -- I've never heard of them?

Do they fit in standard chargers, or do they require something special?

And what does "regulated" mean?

Lithium Ion batteries, you need a special charger for them.

Regulated means they are protected from overcharging and from being overly discharged. Definitely buy the regulated ones, they are a bit more, but they are safer.

Overcharging lithium ion batteries can lead to fires. They should not be left unattended when charging.

I think someone said they are the batteries used to power laptop computers.

If you open a laptop battery pack, you'll find a bunch of 18650 cells inside. Usually between 6 and 9.

Yes they are, that was a problem a few years back with the laptop fires. I am not sure if they were not regulated back then or just had a problem with the regulation. They have gotten better, at least you don't hear about any laptop fires on the news anymore (at least I haven't), but that still does not mean they are 100% safe.

You should never charge them unattended, doesn't mean you have to watch them the whole time, but you should at least be in the same area.

I do not mean to scare anyone, many of these batteries are used daily with out incident. You just need to respect them.

Does anyone know if any of these mounts allow for mounting on a bar that is neither perpendicular nor parallel to the forward direction? I want to mount them to the outside corners of a "trekking" style handlebar. I'm trying to avoid locations that would cause me to lose hand positions as well as work around lowrider panniers and handlebar bag.

I have no experience with it, but this mount might work for you.

https://www.4sevens.com/product_info...roducts_id=388

Anyone have any ideas on this DX P7 light? https://www.dealextreme.com/details.dx/sku.16092

I'm kind of tired of waiting for my 8-mode and might change it up for this. The idea of starting on high seems nice and it's regulated apparently. The battery life looks to be just a little shorter but I don't think it'll matter too much since I'm going to do something silly like hook it up to a 20Ah battery pack (I'm getting two of these P7s).

Yeah, if I didn't want to wait, I'd get one of the two new regulated 5-mode P7s.

Which ones are those?

Edit: I sorted them by release date and I think I see the two you are talking about. One has 2000mAh circuit current output, and one has 2800mA current output? Which one should I get?

Get the 2800mA one. https://www.dealextreme.com/details.dx/sku.16092 The higher current output should mean a brighter light on high.

As an update to the thread, I've had my P7 for about a month now, and it's hands down one of the best bike-related purchases I've made. I just came home from a night ride with it (to a friend's house and back), and the greatest compliment I can give a piece of gear is that I don't have to think about it when I use it. The P7 in front is like that. I know I'm visible to cars approaching me, as well as to cars close behind me, and I can see whatever's in front of me. It's great.

alright i just placed an order for 2 of these babies
the 8 modes one
2 bike mounts
and enough batteries to last me for a 3+ hours trip.
my longest commute time has been 2 hours, so having spare batteries for 3+ hours should be plenty enough.
and also ordered a charger

Entire setup ran up to 150 aprox

still cheaper than the high end systems that only offers 240 lumens.
for the price of 1 HOPE Vision, i now get 2 better flashlights that can even outperform high end heavy lights systems.

I just ordered the 5 mode, batteries and charger as all are in stock. I wanted to go with the higher output P7, but I didn't want to wait 1-3 months as some others have. $65 shipped. Not bad at all!

My two 5-mode P7s finally shipped, I'm very pumped. I can't wait to blast 1000+ lumens + my L2D on my helmet.