Electric Bikes - Anyone got an ebike that powers every accessory?

I currently have a bionx system and many times I wish it could power up all my devices - front light, rear light, and even a handlebar cam. I'd never have to think about changing batteries or charging additional ones. The load would be lighter (esp. without the big battery for my front light). And it'd be a lot easier starting and ending the ride since I could just press one button to power them all on and off.

Do any of you have a setup where your ebike battery powers everything?

You could even go as far as adding a speaker to play music or sound a horn/bell.

You hit the nail on the head! This arrangement is much more convenient and requires less maintenance. Every charge of the main battery provides a fresh power source for the accessories. And with a switching converter, the current draw on the main battery is very low. Unfortunately, the closed BionX system makes this more difficult.

To get 12V, just split off the battery leads and use a DC-DC converter with suitable voltage/current ratings. I'm using a 36-72 to 12VDC 7A converter purchased at Mouser. You can also use a converter from a scooter type ebike but these are much larger and heavier.

How heavy is that converter? Do you have a picture of it? I might attempt it on my old bionx system first and make sure the bionx controller wouldn't have a problem with it. I also have to make sure it doesn't make the bike look klunky and that it's weatherproof.

The converter I used is ultra light - an ounce maybe. But it would need an enclosure or at least need to be conformally coated.

Here's more info and if you search on Bentrider and join you can see a whole bunch of pics of the installation...

http://www.bikeforums.net/showthread.php/736025-Thought-I-d-post-some-info-on-my-build-Actionbent-T1-goes-LIPO-w-9-continent-Motor?p=12694193&viewfull=1#post12694193

On this suppliers website, there is lights, and near the bottom of the page is a picture of a DC to DC converter.
May give you an idea or two.

http://www.ebike.ca/lights/

Thanks. When I get brave and find some time on my hands, I'll have to try that DC-DC conterver.

I am using http://www.current-logic.com/shop/index.php?main_page=product_info&cPath=6&products_id=154 It is about the size of two decks of playing cards.

I am using http://www.current-logic.com/shop/index.php?main_page=product_info&cPath=6&products_id=154 It is about the size of two decks of playing cards.

This is the type commonly found on scooter-type ebikes. As such, they are relatively large and heavy...

This is the type commonly found on scooter-type ebikes. As such, they are relatively large and heavy...

Relatively being the key word. :) I'm using the same sort of converter, only in the 48V --> 12V variety. Compared to the weight of my hub motor and batteries it's fairly light. :)

I'll be switching out too a different one sooner or later though, I want to bump up to a 18S system, so need something to handle the extra voltage.

/ I'm using a 36-72 to 12VDC 7A converter purchased at Mouser. You can also use a converter from a scooter type ebike but these are much larger and heavier.Can you point out the specific model? The search gave a bewildering array of choices. My bike is 48V. TIA

Can you point out the specific model? The search gave a bewildering array of choices. My bike is 48V. TIA

Here's the last one I ordered - this was from Digi-Key.

http://www.digikey.ca/product-detail/en/EVW010A0B41-HZ/555-1177-ND/2341108

I don't think it's a good idea to power accessories with the main battery. It would be great to have a single switch that turned on all four of my LED lights, but LED draw is so low, it is probably more efficient to have separate batteries. At least they won't die when the propulsion battery is depleted. LED bike lights are being produced with rechargable batteries that plug into any USB port for charging. A light accidently left on can't drain the bike's very expensive Lithium main battery, possibly destroying it.

Ah. The age old question. Is it better to use separate batteries. There are pros and cons to each, therefore, there is no single correct answer for everyone.

Good considerations above. And on the other hand, with a DC-DC converter on the main battery, battery maintenance is much simpler and with each charge of the main battery is a fresh charge for all accessories...

Which is best for me is very clear. But with other usage profiles it may not be so clear...

On most ( not all) Bionx batteries there is a DC outlet. The default output is 6V but its software switchable to 12V. Thats only useful if the lights you want to use will handle (self regulate) that kind of voltage. Same for tapping directly into the battery. There are compact LEDs on the market that are self regulating from 9V to 60V DC, they're just not normally marketed to cyclists.


They do give the option of running with or without optional 12V batteries for the lights, and unless your commute regularly depletes your battery - the small additional drain from the lights would be a non-issue. The situation gets more interesting when its applied to other brands of ebikes where 20Ah batteries are available. That would translate into about an 80km range running multiple lights front and back.