Advice requested - powering e-bike lights

Hi, I've hit a brick wall trying to power my e-bike lights and would welcome any suggestions.

• What would I like to do - power front/rear lights on bike and 2 rear lights (trailer) from the main battery.
  
• What are the lights - busch and muller avy e, cycle star 80 and 2 x 2c e led.
  
• Whats the conversion kit - hailong 48v battery and tsdz2 motor with vlcd5 display (only the main connection to the display is used).
  
• What have I tried so far?
  
  • The USB socket on the battery seems to be unpowered - a mobile phone 'battery booster' does not light up for charging.
    
  • There is a cable from the motor to the front speed sensor via a 'y - piece' - when i connect the cable I haveto the 'spare' connector and test (either of) the two pairs of wires coming off this connection, it does not show a voltage on the 20v dc range of a multimeter.
    
  • Power at the battery would be 48v.....
    
  • The Avy e front light has a pair of wires going directly into the light (power in......) and three male spade connectors coming out (+, - and unmarked).
    

  [*]Many thanks for any suggestions

Graham

• There is a cable from the motor to the front speed sensor via a 'y - piece' - when i connect the cable I haveto the 'spare' connector and test (either of) the two pairs of wires coming off this connection, it does not show a voltage on the 20v dc range of a multimeter.
  

 

When you looked for a voltage on these wires, was the VLCD5 "on" AND the "Lights" icon showing on the display ? Pressing the on/off button on the VLCD5 has an additional function - momentarily pressing it turns on (off) the power to the lighting circuit.

 

At least this is what I have on mine, and the lights work fine.

 

Presumably you're testing to see if everything works with just one front and one rear light, to start with ?

the speed sensor is connected to a Y piece with a capped socket. That's the socket for the lights. We can supply the light cable with the correct connector but please consider the risk of the cables getting snagged.

If there is a shortcircuit, you can damage the expensive LCD and controller and leave you stranded.

There is a USB socket in front of the VLCD5, suitable for a phone charger or charging a rechargeable light, maximum current draw is 1A.

Consider powering your lights with a separate rechargeable battery.

Edited November 4, 20196 yr by Woosh

The Avy E is a bit weak in my opinion, I also have a 40 lux light I use around town but wouldn't go on the open road with it, especially on the trike. Even 70 lux is a bit touch and go on that though it does make me slow down at night... Your 42v max light should work up to 50v, mine does but it does get a bit warmer to the touch.

 

Personally I prefer battery powered lights on the trailer:

- no long cable run to worry about

- nothing to unplug when removing the trailer

 

I am reconditioning my trailer at the moment and will be using a b+m Flat S permanent. In France (and some other EU countries) a bicycle must have only one rear light lit at a time. It is a law I am prepared to break - one on the bike and one on the trailer.

 

I am also thinking lighting on the trike and as I run it with either a motor wheel or without I will be using a 12v LiPo brick as power source. I was going to use a buck converter to get 12v from the main battery (I may still have one in there) but as I have a battery on hand might as well use it.

The Avy E is a bit weak in my opinion, I also have a 40 lux light I use around town but wouldn't go on the open road with it, especially on the trike. Even 70 lux is a bit touch and go on that though it does make me slow down at night... Your 42v max light should work up to 50v, mine does but it does get a bit warmer to the touch.

 

Personally I prefer battery powered lights on the trailer:

- no long cable run to worry about

- nothing to unplug when removing the trailer

 

I am reconditioning my trailer at the moment and will be using a b+m Flat S permanent. In France (and some other EU countries) a bicycle must have only one rear light lit at a time. It is a law I am prepared to break - one on the bike and one on the trailer.

 

I am also thinking lighting on the trike and as I run it with either a motor wheel or without I will be using a 12v LiPo brick as power source. I was going to use a buck converter to get 12v from the main battery (I may still have one in there) but as I have a battery on hand might as well use it.

That all very well and good, but any suggestions as to how to actually help the OP with his problem ? The lights he's chosen should work fine, but they're not working at all.

There are all sorts of problems wiring your own lights into ebike systems, especially if you want to use a provided switched lights connector. It's very easy to overload the switching transistor, which is generally only designed for crappy low power lights. If that transistor blows, there can be all sorts of consequential damage to the LCD and controller. You can do it, but you need to know and understand the rating of any provided connectors and your lighting system.

 

Even if you get that all working, there's often problems down the road when the thin wires get snagged and ripped out or when they break inside the insulation from constant bending at the steering head when you mount the light on your forks. I must have fixed more bikes because of wired lights not working than any other single reason.

 

Also, I once had my bolted on wired lights wrenched from their fixings, while my bike was parked at the town centre, which did some damage to the rear mudguard. I can't imagine what the guy thought he was going to do with them, or maybe he was just jealous. Who knows?

 

This is why I'd always recommend a rechargeable battery front light and an AA/AAA cell rear one. Wired lights sound like a good idea, but, inevitably, they end up more trouble than they're worth.

Axa LED Headlight " Blueline 30 E-Bike " 6 Volt Dc

 

and

 

Busch + Müller 2C E Rack Mounted 5V - 15V DC Rear E-Bike Light

 

Hard-wired into VLCD5 speed sensor splitter. Standard TSDZ2 (with throttle) wiring harness. On/Off via VLCD5 display button.

 

 

 

 

Custom-made LED 12v sidelights and Cree front light - both hard-wired to a single battery pack (below, on my tadpole trike - I have a similar hard-wired set-up on the Hase).

 

 

So much easier than having to change / re-charge multiple AA/AAAs. I'd stick with your original idea Graham - there are plenty of advocates of fit-and-forget dynamo-wired lighting systems on the other forums. I can't believe wiring to an e-bike system should be avoided.

 

Presumably, you won't need to worry about wires bending - you'd be mounting the front light at the front of the boom, rather than on the forks ?

That all very well and good, but any suggestions as to how to actually help the OP with his problem ? The lights he's chosen should work fine, but they're not working at all.

 

1. forget about using the output from the controller, hardwire the headlight to the battery, battery off = lights off. Run the wire to the tail light from the Avy E, don't get polarity wrong. Best case scenario it won't work, worst case the buck converter will go pop.

2. wire the trailer lights to a 6-12v battery pack

 

Maybe the OP did get the polarity wrong. When I did I got sound (pop) and lights (big spark). After that the headlight won't work I managed to get a free exchange.

1. forget about using the output from the controller, hardwire the headlight to the battery, battery off = lights off. Run the wire to the tail light from the Avy E, don't get polarity wrong. Best case scenario it won't work, worst case the buck converter will go pop.

2. wire the trailer lights to a 6-12v battery pack

 

Maybe the OP did get the polarity wrong. When I did I got sound (pop) and lights (big spark). After that the headlight won't work I managed to get a free exchange.

I have a pair of Spanninga e-bike specific lights (Axendo 80 XE front, Elips XE rear), which I intend to use with my Cyclotricity 250w/36V front hub kit. I was going to use a Wuxxing light switch but as you say just hardwiring to the battery and controlling with the battery switch makes a lot of sense and keeps things simple.

 

I will use decent thick wiring and anticipate zero problems just as I have had with hub dynamo systems I have fitted and used for 1000s of miles and several years of commuting.

 

Not having to remove lights every time you park in town or at work or repeatedly change/charge batteries etc. is a bonus and in my experience good quality dynamo lights are a fit and forget experience unlike battery lights where many have failed on me after a year or two due to mounts breaking, water getting in or faulty switches.

 

If I had a rear hub or mid drive kit I would go with a hub dynamo simply because it would be independently powering the lights, so a flat e-bike battery will not leave you without lights, but as it is I will carry a couple of mini froglight type things just in case.

Edited November 7, 20196 yr by niggle

Just to emphasise my last point: if you have a rear hub or mid drive kit, as with the OP, a front hub dynamo set-up is the best solution by far, IMO, for the reasons given.

Wiring doesn't need to be very thick, thin 24 awg is plenty, unless you have lights that are amp thirsty. All good awg is 300 - 400v capable, the gauge thickness is for carrying the load and I doubt many lights will carry more then 1a.

The dynamo equivalent of the Spanninga front light I am fitting is rated 60 Lux, rather than 80 Lux of the e-bike version, and a full dynamo set uses up to 3W at 6 volt so 0.5A, so yes under 1A sounds right for the e-bike lights, however thicker wire is more durable and resistant to damage, e.g. at the headtube where it is constantly being bent back and forth and therefore has to have a loop of slack wire to allow for the full range of steering.

 

Other reasons for choosing good e-bike or dynamo specific lights from the likes of B&M, Axa, Hermanns, Spanninga etc. are:

 

1) They are approved to German StVZO standards, which therefore makes them legal in the UK due to reciprocity rules for standards in the EU (British Standard lights are either unobtainable or antiquated NOS filament bulb designs).

 

2) Their front light optics are designed for on road use, with a beam pattern that lights up the road ahead, not waste light by spilling it upwards and sideways where you don't need it and including a top cut off that avoids dazzling oncoming road users.

 

Obviously off road requirements can be quite different but using mega bright Cree XMLs etc. with basic conical reflectors on road has the potential hazard of dazzling oncoming car drivers and gives them a potential legal get-out clause for any compensation, not to mention at least a theoretical risk of prosecution of the rider.

When I did my conversion on my Rockhopper I thought at first that I would have a lighting system powered by the main battery but after thinking about it ,I don't do much night riding and to preserve the range of the bike I opted for a front and rear LED lights with their own rechargeable batteries ..no cables ,they unclip in seconds and you can stick them in your day bag or jacket pocket I think they were 5 euros each ...

Just to emphasise my last point: if you have a rear hub or mid drive kit, as with the OP, a front hub dynamo set-up is the best solution by far, IMO, for the reasons given.

 

And if you have a front hub motor, e.g. because you are using hub gears? Bottle dynamo seems the only option, anyone using the AXA HR? Sounds like the best on the market by some margin but is it good enough?

 

If you want a rear hub motor and a front hub dynamo but don't want derailleur gears then you need a Pinion crank gearbox - interesting combination but could such a bike be electrified?

I also have plans to use a hub gear (Sachs Spectro P5 with drum brake), hence the choice of front hub motor (the hub is reasonably tough, but decided mid drive too expensive to justify for my commuting uses) and why I am fitting e-bike lights running from the e-bike battery (and will be carrying spare blinkies in case of a flat battery). Sturmey did make some 3 speed rear hubs with built in dynamo 'back in the day' and they sometimes turn up cheap on ebay, but the output is only really any good for up to 35ish Lux headlights apparently.

 

EDIT bottle dynamos are a bit crap IMO, slipping in the wet, hard to align correctly, then go out of alignment again too easily, plus not all tyres have the dynamo track. Best one is supposed to be the B&M Dymotec. I had a few as a youngster back in the 1970s and they never lasted well either.

Edited November 7, 20196 yr by niggle

It doesn't make any sense at all to fit a dynamo to an electric bike. Why would you want to use electricity from a battery to turn a motor to turn a wheel that turns a dynamo to generate electricity for a light, while losing some of the electricity along the way, when you can take the electricity directly from the battery or any other one?

 

Motors themselves are generators, so if you want to generate, you don't need to fit s separate dynamo.

Because (if I understand correctly, given that I'm investigating how to convert my pushbike to a Woosh powered ebike), it's not advised to rig up a Woosh battery to LED lights. AA battery powered lights have a host and a half of issues of their own. And even if I managed to rig up lights to an ebike battery, if that went flat at night I'd be without lights. The beauty of a dynamo is that it's always available even if a scrote nicks your battery pack for instance.

In theory it seems odd, but in practice if you have any risk of running the ebike battery flat and ride in the dark it is quite a simple solution. The resistance from a good hub dynamo like a Shimano top end one is tiny, you just can't sense it. If I knew how to get regen power out of an ebike motor I would use that to power lights when the battery is flat, but geared hub motors have a clutch so...

https://www.ebay.co.uk/itm/Waterproof-6x18650-Battery-Pack-Storage-Case-Box-Holder-For-Bike-LED-Light/184020434712?hash=item2ad878ff18:m:moHjlU5IlbI25eHczJjvQsw

In theory it seems odd, but in practice if you have any risk of running the ebike battery flat and ride in the dark it is quite a simple solution. The resistance from a good hub dynamo like a Shimano top end one is tiny, you just can't sense it. If I knew how to get regen power out of an ebike motor I would use that to power lights when the battery is flat, but geared hub motors have a clutch so...

Resistance from the dynamo is tiny when you have the lights switched off, but it's significant when you switch them on. Try it if you don't believe me. Say you have a normal 3W Shimano hub dynamo, you'd have to put in around 5W to get 3W out. That's 5% extra pedal effort if you're able to sustain steady moderate pedalling of around 100W, or 8% extra if you can only sustain 60W. You can't get something for nothing.

 

Also, if you've only got 3w for both lights and they're 6V lights to match the dynamo, they're as good as useless - OK to be seen by, but no good for unlit roads.

I think you're overstating the effect the resistance has when the dynamo is on - those of us who do ride dynamo-option bikes/trikes won't notice a huge difference when actually riding. Theoretically, yes. In Practice, No.

 

Sure, put the dynamo-hubbed wheel into a stand, and compare the free-running of the wheel when dynamo is "off", then "on" (for a hub dynamo - connected or not to working lights). Yes, then you can see there's additional resistance, but when riding ? Nah, I'd suggest that most non-competitive cyclists wouldn't notice the difference when out riding. And the option of having working lights when the e-bike battery has run out of juice ? Yes, for those that have that concern, fit a dynamo light system, and then you can (at least those of us with a trike, hah !) sit back and forget.

 

I'd totally disagree with you on dynamo lights being "as good as useless". If that's your experience, then you've been choosing the wrong lights. Riding on unlit roads with hugely overpowered lights is tiring on the eyes; what makes for better lighting is a system where the light is focussed where it is needed - and not blinding those occasional car drivers who also use those same unlit roads.

Many of you forget that once your ebike battery is too far discharged to sustain 15-20A that your motor requires to operate, it's still capable of outputting 1A that your lighting requires to shine for a long while after the motor cuts out. That's why (to me at least) powering lighting directly from the main battery makes sense more than any other method.

 

Out of interest, has anybody who actually does run their lighting from their bike battery, ever been left without sufficient energy to do so?

Never been without lights when lvc has been reached as voltage is still plenty to run lights , voltage also rebounds to ensure voltage climbs above lvc and riding unassisted in PAS 0 to get home if need be.

I usually only use PAS level 2 so load on battery is low at about 2- 5a max or less then 0.5c per cell.

I think you're overstating the effect the resistance has when the dynamo is on - those of us who do ride dynamo-option bikes/trikes won't notice a huge difference when actually riding. Theoretically, yes. In Practice, No.

 

Sure, put the dynamo-hubbed wheel into a stand, and compare the free-running of the wheel when dynamo is "off", then "on" (for a hub dynamo - connected or not to working lights). Yes, then you can see there's additional resistance, but when riding ? Nah, I'd suggest that most non-competitive cyclists wouldn't notice the difference when out riding. And the option of having working lights when the e-bike battery has run out of juice ? Yes, for those that have that concern, fit a dynamo light system, and then you can (at least those of us with a trike, hah !) sit back and forget.

 

I'd totally disagree with you on dynamo lights being "as good as useless". If that's your experience, then you've been choosing the wrong lights. Riding on unlit roads with hugely overpowered lights is tiring on the eyes; what makes for better lighting is a system where the light is focussed where it is needed - and not blinding those occasional car drivers who also use those same unlit roads.

You have to pedal 8% harder if you have 3W total lights and normally pedal with 60W input. You can't change the laws of physics (first law of thermodynamics) no matter how much you wish you could.

 

Here's some lab test results that show that my estimate was about right, a bit underestimated if anything. Note that they only use a 2W load and their cyclists are somewhat fitter than your average ebike one. Basically, they show that you have to put 7W in to get 2W out at 15 mph.

 

https://www.cyclingabout.com/dynamo-hub-drag-lab-testing/

Edited November 8, 20196 yr by vfr400

From the article you quoted:

 

"Given the leverage of a wheel and the flywheel effect of the rotating mass, dynamo hub drag only has a small effect on your speed.

 

The result for most people is likely to be an extra three to six minutes riding time over 100km, all while getting a good charge to your electronics (or while running lights). "

 

Where did I suggest the Laws of Physics didn't apply ? Nowhere.

 

"An extra three to six minutes riding time over 100km". And really, how many e-bikers ride 100km with their dynamo on ?

 

So, should I be dissuaded from choosing a dynamo as a back-up lighting system = NO !