Running lights from Bosch gen 4 power port...

[Hardtail]

Hi legends,

I currently run front and rear lights from the standard light outputs of the Bosch gen 4 motor, supernova m99 headlight.

It bugs me when it cuts off the motor assist at 10% battery just to keep the lights on due to regulations etc.

Has anyone ran there lights directly from the 12v accessories power port or why it would be a bad idea, obviously keeping the watts in the appropriate range...?

Where can one buy the 12v power port cable for wiring?

Cheers,

 

[Hardtail]

So after much googling I know what I need, but there are no suppliers in the UK, loads in the US.

BOSCH CABLE POWER SUPPLY 3RD PARTY COMPONENT, 1,400MM, 4 POL. NANO MQS-CONNECTOR

The best option for me was from Holland Bike Shop and just take the hit on postage...

Lets see how it works out.

 

[claypot]

So after much googling I know what I need, but there are no suppliers in the UK, loads in the US.

BOSCH CABLE POWER SUPPLY 3RD PARTY COMPONENT, 1,400MM, 4 POL. NANO MQS-CONNECTOR

The best option for me was from Holland Bike Shop and just take the hit on postage...

Lets see how it works out.

Hey Mate,
How did you go with it?
I agree PITA not being able to use the last 10% if using lights.

 

[Hardtail]

Hey Mate,
How did you go with it?
I agree PITA not being able to use the last 10% if using lights.

I have been running it from the AUX power port for 4 months now, the same on my wifes bike. But with some issue!
I run a Lupine C 14 rear light and a Supernova m99 mini pro 25 front light. I don’t have the numbers in front of my but I was sure that their combined amp was less than the max allowed for the AUX port… Unfortunately when running lights on and the M99 on high beam the power cuts out after a few minutes… So it must be overloading the circuit… Running on lowbeam with tail light is fine, or high beam without tail light is fine.
I don’t have any faith in my LBS who enabled the AUX port settings as they kept changing other settings and enabling the wrong thing… for instance they still have the regular light function enabled even though they told me they turned it off… And they returned the bike saying that they updated to the new firmware with higher torque although I told them not to because I already had it updated, all they did was change the settings and replaced Emtb mode with Sport… Anyway.

I simply wired the headlight and rear light together before splicing them into the AUX port connector, maybe there is a better way of doing that, adding a resistor?

I haven’t been out late enough on the bike for it to be a issue at the moment but need to get it sorted.

The last thing is the rear Lupine C14 has an on/off switch but on startup it always comes on, so every start i have to remember to turn it off… I guess that defeats the purpose of saving some battery percentage if it is left on during the day… I haven’t researched another rear light that can be hardwired with a switch.

 

[Hardtail]

Bosch eBike Lighting Cable 1.4m – e-bikeshop.co.uk

This cable can be connected under the Bosch motor housing to power lights directly off the motor, using a the eBike battery as the power source.

www.e-bikeshop.co.uk

Yes, thats what I am trying to avoid.
By enabling the light feature the assist cuts off at 10%, no drop in power or throttling, just cuts off to save the lights. It has left me a few times short a few times just a mile or so from my destination… and it doesn’t matter if the lights are on or off. So I’m seeking a work around.

 

[Hardtail]

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i have the older one.

I appreciate the replies Shockwave but it is not what I am hoping to achieve.

Does anyone with electronics experience have a suggestion of how to wire two lights in to one power port, i.e. do I need a resistor or anything, or is simple splicing the best method?

 

[Hardtail]

you could wire two lights to one output but the power draw will still be the same as you cant change that.

Yes, I wondered if the voltage between the 2 different lights needed to be stabilised or similar. The Supernova M99 will run between 5 - 13,5 V DC and will auto-detect the highest voltage it can run at. So I guess splicing the two is fine.

So I just went over the tech specs, here in lies the problem...

Supernova M99 mini pro 25: Highbeam = 15.5w @12v. or 1.29amps
Lupine C14 tail light: 0.8w @ 12v = 0.07 amps

The 12v Aux power port on the Bosch CX Gen 4 (BDU450CX) = 12v @ 1amp max output...!!! So basically the M99 is drawing too much current for the power port so it cuts out.

The light ports are rated at 1.5amps (1500mA) max 17.4w front and 0.6w rear... Why can't Bosch rate the Aux Power Port at 1.5amps... or higher so that you could practically charge a phone or similar...?

So then I did a little dive thinking that I could restrict the current of the M99, to say 10volts, seeing as though it will run with 6v @ 8w... So amps = watts / volts = 1.33 amps...

@shockwave I now see your point, you can't change the power draw.

Any wizards out there with a workaround? Or I just accept the fact that by having the light ports enabled, even if not in use, you accept that the peddle assist shuts off at 10%... Why have a massive battery if you can't use it efficiently?

 

[claypot]

C

Yes, I wondered if the voltage between the 2 different lights needed to be stabilised or similar. The Supernova M99 will run between 5 - 13,5 V DC and will auto-detect the highest voltage it can run at. So I guess splicing the two is fine.

So I just went over the tech specs, here in lies the problem...

Supernova M99 mini pro 25: Highbeam = 15.5w @12v. or 1.29amps
Lupine C14 tail light: 0.8w @ 12v = 0.07 amps

The 12v Aux power port on the Bosch CX Gen 4 (BDU450CX) = 12v @ 1amp max output...!!! So basically the M99 is drawing too much current for the power port so it cuts out.

The light ports are rated at 1.5amps (1500mA) max 17.4w front and 0.6w rear... Why can't Bosch rate the Aux Power Port at 1.5amps... or higher so that you could practically charge a phone or similar...?

So then I did a little dive thinking that I could restrict the current of the M99, to say 10volts, seeing as though it will run with 6v @ 8w... So amps = watts / volts = 1.33 amps...

@shockwave I now see your point, you can't change the power draw.

Any wizards out there with a workaround? Or I just accept the fact that by having the light ports enabled, even if not in use, you accept that the peddle assist shuts off at 10%... Why have a massive battery if you can't use it efficiently?

Cheers for all the good info mate, very useful for deciding which way I'm going to go, cheers.

 

[Akiwi]

I feel your pain completely.
I absolutely love having built in lights that are always there, and always work without recharging. However, the early cut off is a pain in the royal ass. (I'm not royal by the way)
I try to take that into account when biking, and the remaining range display takes into account the battery reserve when you have lights. On Sunday I did a ride where I got my battery down to 15% and in eco it was showing 3 KM range going up a slight hill.
Luckily, I have only run out once which totally screwed me on a trans-alp where we had to climb an extra 500m up a pass to our accommodation. My motor cut out when I got to 8% battery level. That was the first time I learnt there was an early cut off. I was a few Km and a couple of hundred metres climb away from my destination. Also, the lower the battery charge is, the faster it goes empty.

One thing comes to mind. When I got my light port activated, I was asked what power of light I was installing. I think there was 6v or 12 v option.
I wonder if that makes any difference to the cut off level.
I would love the option of choosing Light or Motor when you need it. At the time I ran out it was light enough that I didn't need the light.

 

[Hardtail]

. Also, the lower the battery charge is, the faster it goes empty.

One thing comes to mind. When I got my light port activated, I was asked what power of light I was installing. I think there was 6v or 12 v option.
I wonder if that makes any difference to the cut off level.
I would love the option of choosing Light or Motor when you need it. At the time I ran out it was light enough that I didn't need the light.

Yeah when the battery indicator is down to about 20% (another good reason to have a dongle) the cut-off is imminent, you don’t know if you will make it 5mins or 5miles…
Someone mentioned earlier that the 6v did not impose the early cut-off, but I would rather take the full light output.

Hopefully someone comes up with a diagnostics clone tool sooner rather than later so we can get access to some of these settings, like they have in the automotive industry… Come on china!

 

[BeBiker]

The only workaround is tapping on the 36v of the battery wires directly, hereby bypassing the Bosch Motor and it's weak output ports completely.

I did this on my E-st900.
What you need is a light with integrated Buck converter, often marketed as "8v-80v"
Or both items separately: A 8v-80v Buck converter, and a separate light.

You can even choose a Buck converter with a double 3A strong USB output.
People somewhat familiar with electronics know this can power (most 7v battery powered) front lights without intensity drop, even together with charging a smartphone.

"yes but warranty"

 

[Hardtail]

The only workaround is tapping on the 36v of the battery wires directly, hereby bypassing the Bosch Motor and it's weak output ports completely.

I did this on my E-st900.
What you need is a light with integrated Buck converter, often marketed as "8v-80v"
Or both items separately: A 8v-80v Buck converter, and a separate light.

You can even choose a Buck converter with a double 3A strong USB output.
People somewhat familiar with electronics know this can power (most 7v battery powered) front lights without intensity drop, even together with charging a smartphone.

"yes but warranty"

I gave up on the warranty as soon as I bought it!
I like this and will look into it.
I wonder how much current the converter will draw when not in use… anything?

 

[BeBiker]

The wires I tapped on the E-st900 are only powered when the bike is ON. So no discharge while the bike is OFF.
There is an ugly red On-Off button on the Buck Converter. When the bike is On and the button is Off: 0W

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[BeBiker]

This is an example of a (ex-battery powered 4-14V ?) light that works without intensity drop if you connect it to the USB.

It has a "battery" connector, but there are Usb to "battery" adaptercables.
I have this now but that leaves me with too much fuss and cable. The plan is to cut it to length and solder decently.

I can run 2 of these lights simultaneously.

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[All4Fun]

To keep wiring original you can buy a Bosch cable set for the Enviolo hub, this set has a tap for the 36V.
Bosch Kabelsatz Rahmen-Akku Nuvinci Harmony - Active / Performance
I made a cable like this myself to run a Supernova M99 Pro on my wife's bike, relay switched by the 12V light port.

 

[BeBiker]

Things start to get interesting here. I did not know that cable set existed.
I suppose that M99 light accepts 12V, so you used a 36v to 12v Buck Converter.

 

[All4Fun]

Things start to get interesting here. I did not know that cable set existed.
I suppose that M99 light accepts 12V, so you used a 36v to 12v Buck Converter.

No, the M99 Pro uses 24-60V, you can hook this light up straight to the battery 36V, it switches on and off by movement.
But i decided to use the light switch on the Bosch computer.
If the light used 12V i needed a converter too.
Furthermore i used a fuse in the 36V wire and a diode over the relay coil to save the Bosch electronics.

As soon as the bike is switched on, the light is on too, it has an automatic day running light function, works now without a problem for about 2 years/ 20.000 Km.

 

[Hardtail]

To keep wiring original you can buy a Bosch cable set for the Enviolo hub, this set has a tap for the 36V.
Bosch Kabelsatz Rahmen-Akku Nuvinci Harmony - Active / Performance
I made a cable like this myself to run a Supernova M99 Pro on my wife's bike, relay switched by the 12V light port.

Thanks for this @All4Fun I guess this is what I have been looking for!
So I can use this cable to replace the current one from battery to the motor and plug the lights in via the blue connector with a buck converter in line, 36v to 12v.

I guess I should add a fuse before the buck converter..?

I would also like to add a switch before the converter to avoid power leak and so that the rear light doesn't come on with every start-up, Lupine C-14 rear light has its own switch but the default when it has power is to be on which is slightly annoying to have to turn it off most of the time.

Do I have this right? @BeBiker

Cheers,

 

[BeBiker]

Seems right !
Some of those converters are internally protected against overcurrent, but an inline fuse is always a good idea.

A switch before the converter might be a good idea, but a necessity if the 36V stays powered with the bike OFF.

If I understand right the m99 needs 5V-13.5V, where the m99-pro can accept 24V-60V.
Is this right ?

 

[All4Fun]

Thanks for this @All4Fun I guess this is what I have been looking for!
So I can use this cable to replace the current one from battery to the motor and plug the lights in via the blue connector with a buck converter in line, 36v to 12v.

I guess I should add a fuse before the buck converter..?

I would also like to add a switch before the converter to avoid power leak and so that the rear light doesn't come on with every start-up, Lupine C-14 rear light has its own switch but the default when it has power is to be on which is slightly annoying to have to turn it off most of the time.

Do I have this right? @BeBiker

Cheers,

First thing in the red +-wire is the fuse, then the rest of the parts.
For switching use a small 12v relais, those are about 15x15x15mm, add a diode parallel over the coil, the coil switched through the light port.
Or use a relais with a build-in diode, or a solid state relais.
The buck-converter switched by the relay.
You could power both front and rear light with the converter.
Doing so, the lights are controlled by the Bosch computer and you have no power leak/ drown the battery.

By my wife's bike the Bosch computer starts the light in wich it was switched off, say it remembers it's last state.

 

[Hardtail]

First thing in the red +-wire is the fuse, then the rest of the parts.
For switching use a small 12v relais, those are about 15x15x15mm, add a diode parallel over the coil, the coil switched through the light port.
Or use a relais with a build-in diode, or a solid state relais.
The buck-converter switched by the relay.
You could power both front and rear light with the converter.
Doing so, the lights are controlled by the Bosch computer and you have no power leak/ drown the battery.

By my wife's bike the Bosch computer starts the light in wich it was switched off, say it remembers it's last state.

This whole venture started to that I could avoid the 10% battery penalty for having the light circuit active in the first place, otherwise I would have just left the lights wired in traditionally like they had been for over a year. But I understand why you have done it that way using the bigger M99 Pro.

 

[Hardtail]

If I understand right the m99 needs 5V-13.5V, where the m99-pro can accept 24V-60V.
Is this right ?

Correct, thus why All4fun runs directly from the battery.

 

[All4Fun]

Seems right !
Some of those converters are internally protected against overcurrent, but an inline fuse is always a good idea.

A switch before the converter might be a good idea, but a necessity if the 36V stays powered with the bike OFF.

If I understand right the m99 needs 5V-13.5V, where the m99-pro can accept 24V-60V.
Is this right ?

Only the M99 Pro is 24-60, see the PDF.

Supernova

 

[All4Fun]

This whole venture started to that I could avoid the 10% battery penalty for having the light circuit active in the first place, otherwise I would have just left the lights wired in traditionally like they had been for over a year. But I understand why you have done it that way using the bigger M99 Pro.

Ah ok, no in my case this doesn't save you from the 10% battery saving, then a manual switch would be needed.
And the Bosch computer needs to be programmed for use without lights.

 

[BeBiker]

My light function was programmed last week, I'm going back next week to remove it, I didn't ask for 750Wh -10%= 675Wh

 

[BeBiker]

I think I discovered some fake news...

Went for a ride yesterday, 12%, 11%, 10%, 9%, 8%, 7%, 6%,...
No shut off.

 

[Akiwi]

I haven't gone till the end for 2 years now, but I do know it shut off at 8% when I didn't expect / need it to.

 

[Hardtail]

I think I discovered some fake news...

Went for a ride yesterday, 12%, 11%, 10%, 9%, 8%, 7%, 6%,...
No shut off.

Interesting... I have heard that if the light function is set to 6v it won't stop assist at 10%...
I have been caught out too many times within 1-4miles from home to know it's no conspiracy, both at night with the light on and during the day with lights off. Unlike the normal condition of PAS slowly dropping off from about 7% it gets to 10/9% and zero PAS, although everything else stays on...

 

[BeBiker]

I haven't gone till the end for 2 years now, but I do know it shut off at 8% when I didn't expect / need it to.

Mine is Gen4 Bes3 "smart", yours must be the Gen4 with the thick square connectors.

Interesting... I have heard that if the light function is set to 6v it won't stop assist at 10%...
I have been caught out too many times within 1-4miles from home to know it's no conspiracy, both at night with the light on and during the day with lights off. Unlike the normal condition of PAS slowly dropping off from about 7% it gets to 10/9% and zero PAS, although everything else stays on...

Mine is (asked to) set to 12V, then there appeared the lights icon on the screen, no lights connected at the moment yet.

 

[Sander23]

Im interested in wiring a light to. When I do my rides I allways have 1250 wh battery with me. If the motor cuts out at 10 % of each battery that mean I lose 125 wh??