Can I Get More 12V?

[Shinysideup]

This is a question for all you EE types. Is it feasible to replace the unit that supplies 12V with something that has a higher capacity?

With all those kWH of capacity in the main pack, I'd like just a bit more watts available to run some 12V stuff. As it is, I can run my jacket (77W) or my gloves (36W) but not both at the same time. I'd gladly give up a few miles of range to be warm on my commutes.

Also, if the replacement unit could throw out a few more volts (like the 15V of an alternator?), then the heated gear would function much better. I've seen as low as 11V off the OEM unit.

The stock unit has been replaced on several bikes for throwing an error, so replacing it with something of better quality might make sense anyway.

I have no idea how to research the availability of alternate units, nor how to install one if available. Any educated guesses?

[frodus]

Do we know what brand it is? Capacity?

How many amps at 12v do you need?

It's possible, but I'm not sure about what they have there to begin with.... So integration could either be simple, or difficult.

I haven't taken mine apart enough to really look.



Imho, it'd likely be easier to hide a small 12 battery and charge off the dc-dc built in and wire things to that. I'd be cheaper for sure..... But it negates your objective of using the built in battery.

[kingcharles]

You could also lower the 12V usage of the running lights by using LED and HID.
This way a little more is available for heated gear.

But there are lots of DC-DC converters that can be added to the bike. I cannot advise on the right choice but it should be possible to replace the existing converter for a bigger one or add a second converter. You are tapping into the high voltage side so be really careful or let the work be done by an experienced engineer.
Things to check:
It doesn't interfere with the CAN bus
Increase the fuse rating (high voltage too)
Upgrade the wiring

[protomech]

Feasible yes. It may be less intrusive to add an additional unit than to replace the stock unit.

Check out the discussion here, for a related project on a Zero bike.
http://electricmotorcycleforum.com/boards/index.php?topic=3766.5



The Zero bikes use a Sevcon 12V DC/DC converter, which is switched with the key position to turn on the display (and other 12V electronics) and enable the motor controller. The Empulse may be similar. I guess this is the Zero DC/DC unit, here's a less expensive alternative that might work just as well.

It might be easier to just run the jacket from the bike DC/DC converter and use battery-powered heated gloves, which also frees up wires going to your hands.

[Chocula]

First, this is just an idea, not necessarily a good idea.  I am also NOT an electrical engineer.

Since each of the 7 modules is roughly 15 volts, one might be able to tap a single module and get what you want with nothing more than an inline fuse.  Ideally you would tap the module that goes from 0 to +15 volts over ground.  Any draw on this cell would place that module out of balance with the remaining modules which the charger would have to balance.  If the draw is small enough, that may not be a big deal.  Also, anything connected to this when the bike is charging would need to be able to handle the increased voltages used to charge that module.

A better idea might be a small rechargeable battery pack such as http://www.cyclegear.com/MOBILE-WARMING-Battery-Pack


Chocula

[frodus]

Don't tap off that cell.... It's a bad idea as it always unbalances the pack every time.

Can anyone tell me what the dc-dc is? I think maybe something like surepower.