E-Bike lights - Are they worth getting?

[Llewpart]

Hi,

I've converted my bike in to a front wheel hub ebike using a Cyclotricity kit.

Having looked online to see what additional things I should get I have come accross ebike lights.

Can anyone tell me if they're worth getting? What are the pros and cons?

One thing I'm not sure of is which cable could it be attached to to make it compatable.

Any sugestions on which one to get?

Sorry for so many questions in one thread. Thanks

 

[indianajo]

Most cheap controllers don't have a connector for a bike light. Finding a matching connector to one that did would be a quest for a roc. The ebike connectors mostly don't have names and when they do show up on alibaba they are sold in lots of 10000.
I bought a headlight & taillight powered by a rechargeable battery. they charge through a micro usb port, just like my cell phone. I use the same charger. Because having a lights is so important I have another lower power light on each end powered by a throw away battery. The front battery light flashes, whereas the front 100 lumen one I leave on steady to see potholes & slab separator ridges. I leave the secondary rear light off to save the battery unless the rechargeable one runs down. That way I don't have to measure the battery before every 3.5 hour trip.

 

[6zfshdb]

Why waste valuable bike battery power on a light? Get a handlebar mounted light with it's own built in rechargeable battery. That way, it can be removed from the bike and double as an ordinary flashlight.

 

[Marci jo]

Even though I never ride at night, I use lights both front and back. A fair amount of my routes are streets and roads and for sure I want to be as visible as possible to drivers.
There’s many rechargeable lights on the market.
My challenge is to remember to turn them off to save the battery.

 

[antboy]

Have you tried contacting the kit maker to see if integrated lights are an easy add-on? It looks like their controller uses standard julet connectors.

I definitely prefer integrated lights, coming from a regular bike and having run into the annoyance of forgetting to charge a light, or forgetting to bring it. Integrated lights have almost no noticeable impact on range per charge.

Plus, anything to reduce the number of wall warts in my life is always a good thing.

 

[Dallant]

I think lights are worth it even in the daylight as it just might make you seen & noticed by the incredibly distracted drivers out there. Mine in this pic are integrated on my Trek Allant+7 and seem quite bright to me. BTW, I just moved my light from the top of the fork to the handlebars, which I like much better.
Rechargeable lights seem a great alternative if they are bright enough.

 

[Sierratim]

I always ride with lights, even during the day, and would highly recommend them. I equipped my original DIY ebike conversion with a rechargeable seat post mounted tail light and a handle bar mounted head light. During the day I always had them on in flash mode to be better seen in traffic.

I had looked into powering the lights from the controller. Even though it was a higher quality unit from Grin Tech, there wasn't a light output. My next option was a DC-DC coverter to drop the 48V battery voltage down to 12V for a light. Doable, but it seemed like just too much extra hardware and wiring hassle.

My current ebike came with wired in running lights, plenty bright for daytime use, but just not enough for the evenings. I added rechargeable lights for this as I did for my DIY ebike.

 

[Captain Slow]

Why waste valuable bike battery power on a light? Get a handlebar mounted light with it's own built in rechargeable battery. That way, it can be removed from the bike and double as an ordinary flashlight.

+1

 

[Mr. Coffee]

How often are you planning on riding at night? And are you night-riding in dark and spooky forest or in urban areas? The requirements differ dramatically.

There are a veritable cornucopia of excellent lights available that can match any budget. Restricting yourself to e-bike only lights greatly limits your options and you are paying more for what is, at best, a small convenience.

I'd heartily recommend helmet-mounted lights as well.

 

[Chancelucky2]

My e-bike has built in lights that don't turn off unless the bike is totally off. I wasn't wild about the idea, but I do feel safer. The big advantage is that as long as your motor has battery power your lights have power. It does use power that might otherwise be mileage, but nothing extreme.

 

[zzRider]

Why waste valuable bike battery power on a light? Get a handlebar mounted light with it's own built in rechargeable battery. That way, it can be removed from the bike and double as an ordinary flashlight.

My ebike light is 5watts. Based on a 48v/13aH battery, it is only drawing 0.1042 amps, or 0.00217 volts.

Hardly a drain at all. Plus it turns off automatically when the controller switch is off. I don't have to worry about any batteries giving out or recharging using a USB or otherwise.

For safety, especially on narrow 2-way bike paths, it's a must to have at least a front light. The particular one I purchased had a dongle for attaching a tail light as well, which I did. The connector for the headlight did not match the connector for a light on my controller--so what, you just clip the connectors and attach the wires directly.

 

[Alex M]

Why waste valuable bike battery power on a light? Get a handlebar mounted light with it's own built in rechargeable battery.

Lights consume very little, average ~10W total for both headlight and rear light. If you only use them after dark, 2 hours ride will take 20WH. With 600WH battery running 90%-30% charging cycle, your lights will cost you 5% of the range. This is a small penalty to avoid the risk of riding with no lights because you forgot to recharge it.
(Ops - didn't notice that Zzrider has already addressed the issue).

 

[6zfshdb]

Lights consume very little, average ~10W total for both headlight and rear light. If you only use them after dark, 2 hours ride will take 20WH. With 600WH battery running 90%-30% charging cycle, your lights will cost you 5% of the range. This is a small penalty to avoid the risk of riding with no lights because you forgot to recharge it.
(Ops - didn't notice that Zzrider has already addressed the issue).

Your point is well taken if you can get away with 10 watts of light. Where I ride, I need 20 watts or more (off road, tunnels, etc). I use a variable output 12000 lumen handlebar mounted light that can recharge if necessary via the USB port on my bike's display.

It should also be noted that a fixed bike mounted light won't help you fix a flat in the dark.

 

[Sierratim]

My ebike light is 5watts. Based on a 48v/13aH battery, it is only drawing 0.1042 amps, or 0.00217 volts.

Hardly a drain at all. Plus it turns off automatically when the controller switch is off. I don't have to worry about any batteries giving out or recharging using a USB or otherwise.

For safety, especially on narrow 2-way bike paths, it's a must to have at least a front light. The particular one I purchased had a dongle for attaching a tail light as well, which I did. The connector for the headlight did not match the connector for a light on my controller--so what, you just clip the connectors and attach the wires directly.
View attachment 57273

Just to be clear about the maths here your 5W light probably runs at a constant voltage of 6 or 12 volts supplied from the controller. Since power(watts) = volts x current(amps), this light will draw 5W/6V=0.8 amps or 5W/12V=0.4amps. The power draw at 5w is of course constant. For a 500Wh battery this represents ~1% of the battery capacity per hour of use. Still a small investment for a decent running light. Lights powerful enough for night rides will draw more.

For bike powered lights it is important to not overload the lighting circuit with overly powerful lights as each brand has a limit to the power that can be provided to the lights. Supernova published a compatibility chart several years ago, attached. It's not comprehensive nor up to date, but it is still a good guide to upgrading lighting.

 

[Sierratim]

The Supernova attachment didn't make it with my original post. Trying again...

 

[zzRider]

Lights consume very little, average ~10W total for both headlight and rear light. If you only use them after dark, 2 hours ride will take 20WH. With 600WH battery running 90%-30% charging cycle, your lights will cost you 5% of the range. This is a small penalty to avoid the risk of riding with no lights because you forgot to recharge it.
(Ops - didn't notice that Zzrider has already addressed the issue).

I attempted to address it, but had to look up some watt-to-amp and volt-to-watt calculators. I may not have applied them correctly, however!

 

[zzRider]

Just to be clear about the maths here your 5W light probably runs at a constant voltage of 6 or 12 volts supplied from the controller. Since power(watts) = volts x current(amps), this light will draw 5W/6V=0.8 amps or 5W/12V=0.4amps. The power draw at 5w is of course constant. For a 500Wh battery this represents ~1% of the battery capacity per hour of use. Still a small investment for a decent running light. Lights powerful enough for night rides will draw more.

For bike powered lights it is important to not overload the lighting circuit with overly powerful lights as each brand has a limit to the power that can be provided to the lights. Supernova published a compatibility chart several years ago, attached. It's not comprehensive nor up to date, but it is still a good guide to upgrading lighting.

You know, had I thought of it when doing the wiring, I would have connected a voltmeter and tested the voltage from the controller to the light connection. In any case, I'll sacrifice some battery usage for the added safety. I've noticed it's easier to judge distance from oncoming bikes on a narrow 2-way bike path if the bike has a light. Makes passing safer to know how close they are coming at you!

 

[Llewpart]

Thanks for all your information everyone, I appreciate all the help.

At the moment I'm lit up like a Christmas tree when I ride in the dark, which is a good thing Plenty of lighs and high-vis. They take up a fair amount of room on the handle bars now that I have an additional throttle an speedometer on it. But, I'm happy to do that if it keeps me safe. (my helmet light it also handy)

 

[Dallant]

So far I haven’t ridden my ebike in the dark but have considered adding a helmet light just to improve my visibility to drivers.

 

[Alex M]

It should also be noted that a fixed bike mounted light won't help you fix a flat in the dark.

Smartphones have a flashlight app (or you can download one for free), it's surprisingly bright and lasts a long time. It took me a while to realize that with a smartphone I don't need a flashlight, at least in urban environment. $2 folding fake leather protective case - you know, like a notebook - will hold it at the angle. Not for use in heavy rain, of course.