Running bike light off 36V Bosch battery

[mfj197]

I'd like to run my DIY front light from the Bosch main battery to avoid having to charge up two separate battery packs. The Bosch system can of course provide switched outputs for bike lights but these are unfortunately 6V and low wattage - 2.4W rather than the 17W I need. Is there a way of tapping into the 36V system power without cutting the main power leads? I seem to remember there being a wiring harness with a takeoff for running the Nuvinci hub gear but I cannot for the life of me find it online!

Michael

 

[Deleted member 4366]

Dead easy if you can get hold of the connector that's on the charger, then you could just plug it in to the charge socket.

Why do they have to use daft connectors instead of standard ones?

 

[mfj197]

True enough d8veh.

I'd quite like to keep the wiring internal if possible. Here is the link to the NuVinci Harmony OEM installation manual which talks about the separate "Power Harness" which, it helpfully states, "is purchased from Bosch". No part numbers though.
http://nl.r-m.de/wp-content/uploads/Harmony-OEM-Installation-v1.3-15-OCT-2013.pdf

 

[D8ve]

17 watts implies a bulb light
And is a half amp drain much better to go led and keep your battery power for movement. Replacement led bulbs are around £12. That could fit into most lights..

 

[Deleted member 4366]

If you don't want to use the charge socket, you'll probably have to open up the battery receiver and solder a couple of wires to the back of the battery connector. Hopefully, there'll be room in there for a fuse. You might have to drill a small hole to let the wires out.

 

[mfj197]

17 watts implies a bulb light
And is a half amp drain much better to go led and keep your battery power for movement. Replacement led bulbs are around £12. That could fit into most lights..

No, it is already LED. It's a twin lighthead LED setup with a road dipped beam - build thread below.
http://forums.mtbr.com/lights-diy-do-yourself/build-thread-double-xm-l-road-lights-746967.html

Michael

 

[Martin@e-bikeshop]

I'd like to run my DIY front light from the Bosch main battery to avoid having to charge up two separate battery packs. The Bosch system can of course provide switched outputs for bike lights but these are unfortunately 6V and low wattage - 2.4W rather than the 17W I need. Is there a way of tapping into the 36V system power without cutting the main power leads? I seem to remember there being a wiring harness with a takeoff for running the Nuvinci hub gear but I cannot for the life of me find it online!

Michael

I can get you a piggy back harness should you require it?

Martin

 

[mfj197]

I can get you a piggy back harness should you require it?

Martin

Martin, that sounds like just the thing - thanks. How is it fitted? Is it a Bosch part, and how much?

Michael

 

[Martin@e-bikeshop]

Martin, that sounds like just the thing - thanks. How is it fitted? Is it a Bosch part, and how much?

Michael

What system have you got?

 

[mfj197]

I haven't yet, but Bosch Generation 2.

 

[Martin@e-bikeshop]

If you buy from me I will throw it pre wired in

 

[mfj197]

If I were buying from you I think it would be a Yamaha rather than a Bosch! And much as I might like I can't choose the bike based upon ease of wiring my lights in to it.

So how much is the harness? I guess it's easy enough to fit?

Michael

 

[Martin@e-bikeshop]

They did do a piggy back harness, but I cannot seem to find it on the spares list now. Let me do some digging around and I will come back to you shortly.

 

[Martin@e-bikeshop]

Its £54.99, It does state if used with anything but for the NuVinci it will void warranty. A cheaper option is to just solder off the back of the Battery terminal ports?

 

[mfj197]

Martin, thanks. Yes, faced with that sort of money I would just keep the 4-cell li-ion pack I use for the lights at the moment! Soldering off the back of the main battery terminal ports would be an option (I'm an electronics engineer by background) but would that affect the warranty too?

Thanks for your help!

Michael

 

[Martin@e-bikeshop]

Technically Bosch advise against any electronics modification.
Why not use a USb recharge lamp and run it off the head unit?

https://www.e-bikeshop.co.uk/eBike-Spare-Parts/bosch-usb-converter

 

[mfj197]

Well, the USB 2.0 standard is for supplying current up to 500mA at 5V. That's 2.5 watts. My home-made lights use 17 watts so I need a bit more beef than USB can handle.

Thanks for the information Martin, much appreciated.

Michael

 

[Geebee]

It is starting to become clear why buying a high end ebike is not for everyone, to many expensive proprietary parts so it discourages tinkering, battery is a major running cost, getting a cable or switch is silly money etc.
Good solution if you want a turn key product but still dear to run.

 

[Martin@e-bikeshop]

Well, the USB 2.0 standard is for supplying current up to 500mA at 5V. That's 2.5 watts. My home-made lights use 17 watts so I need a bit more beef than USB can handle.

Thanks for the information Martin, much appreciated.

Michael

No Worries, forgot you were wanting to run that current.
Btw, if you want to run off battery there are 3 wires, from memory its the Red & Blue wire's that you need on the Performance system.

But don't hold me to that when it all goes bang

 

[Ibismojo-er]

Is there a connector to do the same thing but to charge phones, GPS etc on a Sduro allmtn rx with the Yamaha motor.

Also can lights be powered the same?

Thanks in advance