vol

Most discussed are brightness, but battery life is also very important. Among the headlights and taillights mentioned here or known to you, which have the best battery life on full charge (stay bright for longest before recharging)?

Alternatively if you know which one have the worst battery life, feel free to mention, too.

I had the $20 magicshine clone that could last about 3 45-minute rides (on low constant setting) before needing recharging, but one day it suddenly died during my ride without warning---without going dimmer, just from bright to completely off.

The taillights I've used (radbot 1000, cygolite hotshot and serfas TL60) could probably last about 3 short commutes, too. I usually set them on flashing mode.

a1penguin

That is one reason why I prefer single 18650 battery flashlights. I carry a spare battery in my seat bag. I also don't like cords and battery pack added to my small frame.

I get at least 4 hours on tail lights in flashing mode. I charge them over the weekend because it is convenient rather than they require charging.

I think 3 45 minute rides on a magicshine on high isn't too bad. The brighter the light, the more juice it requires. I use 3400 mAh batteries in my flashlights. Perhaps upgrading the batteries in your battery pack to higher capacity ones will give you more run time.

vol

I do that, too, but wonder if it's better to bring the charger to work and charge it right before using the light. If it's charged to full compacity on weekend, it will be on full charge for the duration between weekend and the time it gets used (say Monday night). I thought keeping the battery on full charge is not good?

canklecat

The Blackburn 2'Fer gets the spec'd life per charge: 5 hours flashing, 1.5 hours steady (maybe a bit longer). But it's mainly a front or rear (white or red) warning light, bright and evenly diffused, visible from the sides, but not really concentrated enough to be a useful headlight. At $25 it's a pretty good value. I mostly clip it onto the front of my hat band, and have another flashing red LED on the back of my hat. With the bright flasher that way it really gets attention when I turn to look toward drivers pulling toward intersections and driveways. Lights up every reflective sign out to 100 yards. So far, so good, nobody has pulled out in front of me.

The Vivo-Bike Illuminati seems to get pretty good life per charge. I haven't measured it but have managed three one-hour rides between charges, and it hadn't exhausted yet. It's just bright enough to serve as a headlight, but I don't do much night riding. Good for $20 with the replaceable battery tail light, and there are others in that price range.

The 2'Fer and Illuminati are both USB rechargeables and include the USB cables. They'd probably work off my phone and Kindle tablet chargers too but I haven't tried 'em.

If I was riding at night more or commuting I'd look for something brighter with a battery pack to mount somewhere on the bike. And if I was choosing a new bike a hub dynamo would probably be on my priority list.

znomit

Plenty of the cheap lights are OK but they usually rip you off on the batteries, often getting a battery from a reputable source will double your run time. I use Hunk Lee on ebay, the genuine magicshine stuff is probably a good bet too.

gios

I use two rear lights; Thunderbolt and Hotshot. My daily ride is :55 - 1:00 a day, and I know my thunderbolt (I always use high blinking) will be dead sometime during the third ride, so I charge it after two. The hotshot (blinking) lasts 5 rides (just yesterday morning). I have not ridden it until it dies, so maybe I'll try #6 this morning. My back of the envelop bike log (below) keeps track of when to charge.

day, date, time, distance, calories, garmin 500 percent charged, th # of rides since charge, hs # of rides since charge.

br 97/98 ^ 100 br is before ride front 97 psi, rear 98 psi, topped off both to 100 psi

It looks better when I enter into my txt file using tabs to line up entries.

fr 10.09.15 :55:37 15.3 870 36 th 2 hs 5 .. th & hs chgd
th 10.08.15 :54:43 15.4 805 41 br 97/98 ^ 100 th 1 hs 4
we 10.07.15 :55:21 15.3 767 46 th #2 hs #3 , th chgd af
tu 10.06.15 :54:28 15.3 793 52 br 90/90 ^ 100 th #1 hs #2 rain yesterday
su 10.04.15 :59:55 15.4 753 58 th #3 hs #1 th dead..chgd ar, hs chgd br
sa 10.03.15 :56:03 15.3 766 64 br 97/97 ^ 100 th #2 hs #5
fr 10.02.15 :57:53 15.4 717 70 th #1 hs #4
th 10.01.15 :58:56 15.3 730 76 br 97/97 ^ 100 th #3 dead hs #3 .. th charged

Looigi

Keeping the battery at full charge is less than optimum but sometimes it's not practical to charge right before riding. With LiIon batteries, the longest useful life in terms of total run time before needing replacement will be if you charge the battery just before use and discharge it to ~50% of capacity before recharging. I try to approximate this as best as practical with my devices.

chasm54

Personally I run the Cateye Volt1200. In "all-night" mode, which is bright enough for most road use, it runs 17.5 hours between charges. In the more noticeable hyper-constant (all-night mode plus a strobe effect) it runs 14.5 hours.

It's an expensive light, but you get what you pay for.

PaulRivers

Some of us run a dynamo light - get a dynamo front hub and it produces electricity as you ride, powering an led front light and tail light. Can't run out of battery ever with it.

vol

Dynamo works only when the wheel is turning, but I think it's important to have the light on even when stopped at red light or when you have a flat etc. and stop in the middle of the road. (Also, I suppose when the bike speed is very slow, the light would be dimmer?)

fietsbob

Now LED headlights have a charged capacitor in the circuit.
that keeps the light on for several minutes after you stop.

Older bulb lights did not do that.



Just 'be seen' low watt lights drain the batteries slower , and slower yet if it has a flach mode.

brighter = more drain of battery..
so the half watt light has a 3x longer battery usefulness than a 2 watt.

znomit

Most dynamo lights have built in capacitors that keep the light going dimly for ~5 minutes after you stop.
Brightness increases up to around 15-20 kph but at the slower speeds you don't need as much light.

ItsJustMe

Magicshine clone with an 8 cell pack, and a Magicshine taillight. The whole set runs probably 5 hours on a charge if everything is cranked up all the way. I usually dial back the light to 1/2 power when I'm on paved roads. I really don't know how long it lasts, I just charge it over the weekend.

ColonelSanders

Your question should take into account something that you may not have thought about and that is how powerful a light do you want?

The brightest lights often have the shortest run times, but one might buy a powerful light but only use the lower settings and vastly extend the period between charges.

vol

I mean a reasonable comparison, i.e., for about the same brightness, which are more lasting. A good balance between brightness and duration.

RR3

Fenix BT20 running on 3400Ah Panasonic 18650 batteries run around 24+ hours, 8,75 hours, and 5.5 hours on 100, 300, and 450 lumen settings. The 300 lumen setting is much brighter with more throw than any dynamo setup with the one considerable drawback that one needs to make a battery change on very rides. I carry a spare pack with batteries already in it or sometimes I mount redundant lighting systems. I had thought my parsimonious lighting choice would be a disadvantage on 1200k randonnees but I have had no real problems with batteries on such rides. Obviously a generator is convenient but I prefer the extra brightness and portability of battery powered lights accepting the slight inconvenience of changing batteries.

EastCoastDHer

Yes. And thank you. 18650 batteries typically last longer. Buy good ones, the extra cost is worth it. I use nitecore 2300mah batteries in my flashlight (nitecore p16) and they last twice as long as the trustfire brand and the no name brand ones i bought online. Buy a good quality light and better quality batteries, because your life depends on it.

PaulRivers

You left out the high mode which is 750 lumens for 1:50.

I haven't used it but I am very skeptical of that claim, dynamo lights are designed to have a lot of throw and 300 lumens isn't to far away from the amount of light the latest dynamo lights put out.

I do like the sounds of the LED color output (neutral white) on the bt20. A lot of other lights use cheaper bluish/purplish output led's whose lumen output is higher but real usefulness is lower. My Phillips Saferide has a similar led that's very very nice to ride with at night because the color temperature is similar to night time colors.

I also wish they just made a double-sized battery pack so one didn't have to swap packs out. And...that you could plug in the pack and recharge it without removing it from the bike. It saves a lot of time if you ride in the dark regularly to just leave the batteries plugged into the charger on the bike.

vol

This kind of psychology is being taken advantage of by manufacturers and that's why many cycling accessories such as lights and hi-viz products are over priced.

The reason I don't spend $$$ on lights is so that I can afford losing them or dropping them on the floor.

RR3

Paul,

I do not use the 750 lumen output and have not measured the run times; however, Fenix's published times are based off inferior batteries than the Panasonics that were used for the times that I listed. The times I listed are actual measured runtimes usings 3400AH Panasonic 18650 batteries. I probably would get 2:20 on the 750 lumen setting but this is a pure guess. I only use the 450 lumen setting at high speed on demanding descents' otherwise, I am happy on the 300 lumen setting.

I have literally ridden with thousands of randonneurs at night. Not a single dynamo setup throws as much light as my setup does at the second lowest output setting (300 lumens); additionally, the tone of those dynamo lights is very white and harsh to my eye. I find eye fatigue to be an issue for me on long rides at night. As a "fast randonneur" throw is essential to me and the dynamo light just don't cut it yet especially in rolling terrain where my downhill speeds quickly outpace the throw of dynamo lights. Period. You can chose not to believe my claim. I have not ridden with a single dynamo equipped rider who will descend full speed at night-they are always on the brakes unless they are on my wheel (using my lights). Again, you can accept this observation or not. Also, there were relatively few dynamo setups in the 80H vendette groups at PBP. Why? I have not seen any objective comparison data; so, your skepticism contradicts my direct experience and observation. I know a day will come that I switch to dynamo lights but not now. If I do the TransContinental or TransAmerica, I will accept the convenience of dynamo lights especially the ability to charge other devices.

I wish Fenix would sell the empty battery case separately. What a pain. I had to buy three complete lighting systems in order to have the three packs for PBP although I only needed two packs, I wanted a spare just in case I was slower than planned. The connector that Fenix uses is a bit odd too. I usually just carry two packs. Unplugging at a control takes maybe 15 seconds. Not a big deal but not the perfect lighting solution either. I am constantly looking for better lighting but right now, the Fenix BT20 best meets my needs.

Since I have three sets of the Fenix BT20, let's do a night brevet together next year. We can mount a set on your bike and you can switch back and forth. I will do the NJ 400K and 600K.

Garfield Cat

It depends on the rides that you do. I have to think that the engineers who design the light will also make sure the battery power supply is adequate for a wide range of circumstances.

So the question about what's the longest before recharge is about what's your ride. Recharging some of these lights is as simple as plugging in the USB cable to a 2.1 amp charger like Belkin. I say "so what" about recharging frequently. Just do it the night before.

PaulRivers

Like I said I agree with you there.

Lol if you lived anywhere near where I do (minnesota) I'd take you up on an offer to try one. It's totally possible I'm younger than you, but I'm getting a bit to old to be doing overnight bike rides (biking all night) lol.

Unfortunately, I do have to agree that so far I have been unable to locate a dynamo light with as nice of a color temperature as my Saferide Gen 2 (and assumably your bt20). The Cyo's are more blue/purplish. The latest Schmidt is white but it's an odd white - not the right color temperature. The first saferide dynamo is "crystal" white which is an enjoyable color output but makes vision outside the main beam difficult. I ordered the Gen 2 Saferide dynamo but - sigh - the color temperature is ok but they made it a cheaper model that a lot less "throw" down the road and a slightly-to-bright beam pattern.

There was a dynamo light that made a point of using a neutral white led (or something similar), but it was an older model with lower output and I'm blanking on the name at the moment. (Edit, found it: Herrmans H-One S dynamo).

The B&m Iq-X is coming out, replacing the Cyo as the top dynamo light, but no word on it's color temperature. Or if there will be a Schmidt equivalent and what it's color temp would be.

If the bt20 could be plugged in while left on the bike I'd buy one just to try it out.

It would certainly be interesting to see a side-by-side comparison.

RR3

if the Revo had a switch to turn it off and could charge accessories, I would probably build up an SP dynamo front wheel.

Paul, you explained it well. The color on a lot of these dynamo lights is hot. I find it annoying and fatiguing when these lights are behind me.

I am not in love with the Fenix BT20 but it lasts a long time (full night) and provides a good throw. It meets my needs.

I am hopeful a Revo Mk2 comes along (it puts out a ton of light) remedying the two above fatal limitations.

PaulRivers

I remember looking at that light when I was considering one for mountain biking, and how odd/annoying it was that they left off an on/off switch. Seemed like a nice mtn biking light otherwise. Not sure if it would work well on the road - mtn bike lights tend to be designed to put light where you don't need it. Not just the cutoff, but you have more trouble getting the throw down the road you need.

I would include many of the battery lights I've used in that as well, but otherwise I agree. I'd really like to see more lights with color temp / light output.

I'm not personally trying to talk you into a dynamo. Certainly a dynamo is never going to put out as much like as a 800 lumen light with nice color output.

I do hope we'll see dynamo lights with better color output this year though...

kickstart

Its interesting that a few find color temp something to consider. I've noticed it, but find it to be totally irrelevant.