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[SwampNut]

Zero says you cannot connect anything to the 12v battery, but it's unclear why, or whether something with a very tiny draw would affect it.  I want to power a dashcam that wants 12v constant plus 12v switched.  Any ideas?

[Specter]

Here's another thread that is going on now in the forum, that may or may not be of help to you.

https://www.electricmotorcycleforum.com/boards/index.php?topic=12792.0;topicseen

Aaron

[SwampNut]

Thanks, adding a small battery pack is my last-ditch option.  The SR/S already has connections for heated gear and ignition-switched accessories, that part is fine.  But I can't find any constant 12v power.

[TheRan]

The gen 3 bikes have a separate 12v battery, apparently located under the seat, so you can just wire to that. From the images I could find it has threaded terminals so just crimp some ring terminals onto the dashcam wires.

[SwampNut]

The gen 3 bikes have a separate 12v battery, apparently located under the seat, so you can just wire to that. From the images I could find it has threaded terminals so just crimp some ring terminals onto the dashcam wires.

Zero says you cannot connect anything to the 12v battery, but it's unclear why, or whether something with a very tiny draw would affect it. 

[LeverCommaJohn]

The 12V battery is *very* small. It is used primarily as a power source to energize the main battery pack contactors, which then provide power to the DC to DC converter, which then provides the main 12V accessory power. If your 12V battery drops below the energy needed to power the contactors, then your bike is dead.

I, too, was looking for a constant 12V power supply and determined that it wasn't the best idea to draw from that battery, because if I knew what my constant power draw was and calculated that the 12V battery would go flat within a few days if the bike wasn't ridden.

[SwampNut]

I, too, was looking for a constant 12V power supply and determined that it wasn't the best idea to draw from that battery, because if I knew what my constant power draw was and calculated that the 12V battery would go flat within a few days if the bike wasn't ridden.

That's probably why they say not to use it, rather than giving guidance on it.  The dashcam would essentially use zero power unless programmed for parking mode (I wouldn't).  It wants the constant power so it can record for a few seconds after turning off the bike, and then properly save the file.  I think I'm going to bench test it and see if I switch off both wires, will it still save?  Or will it corrupt the file?

[SwampNut]

Oh, and yes, it's shockingly small, the only spec I could find for it is 1 amp hour.  A full size ICE bike would have 9-14Ah.

I wonder if the bike will maintain the 12v battery if it's plugged in, but not ridden?  Like the Tesla will?  Or it has to be ridden or at least "on?"

[DonTom]

Oh, and yes, it's shockingly small, the only spec I could find for it is 1 amp hour.  A full size ICE bike would have 9-14Ah.

I wonder if the bike will maintain the 12v battery if it's plugged in, but not ridden?  Like the Tesla will?  Or it has to be ridden or at least "on?"

Measure the voltage on that battery off and on and see if there is a difference. That will let you know. If it's above 13VDC when off, it is being kept charged when off. If you see the voltage drop to something like 12.7 VDC when off,  it is not being charged.


Best to wait a few minutes to check the voltage after the bike is off after comparing to being on. That way you will notice a slightly larger difference if there is one. 


-Don-  Reno, NV

[SwampNut]

I have a data logger, I should leave it hooked up.  If it's like the Tesla, it won't HOLD the battery voltage.  The vehicle cycles charging on and off, because keeping the DC-DC converter on all the time is very inefficient.  I know the Zero does not do that because you'd kill the main battery in just heat loss.  I just don't know if it would kick on by itself, like the Tesla, if the 12v got low.  Something to learn I guess.

[LeverCommaJohn]

As far as I know, there is no way for it to keep it charged, as the main contactor going to the drive battery isn't engaged, so the DC to DC converter *can't* keep the battery charged. Or, to put it another way, if you don't have ACC power, then your 12V battery isn't get any power either.

[SwampNut]

Sadly it does seem that would be the case.  I guess there's just less need to maintain it, compared to the Tesla which has "housekeeping" to do all day.

[TheRan]

According to the unofficial manual it periodically charges the 12V battery even when the bike is keyed off. I don't know if this is a time based thing or if the charge level is actually being monitored and the battery is only charged when needed.

https://zeromanual.com/wiki/FST_Platform/12V_Battery

[LeverCommaJohn]

According to the unofficial manual it periodically charges the 12V battery even when the bike is keyed off. I don't know if this is a time based thing or if the charge level is actually being monitored and the battery is only charged when needed.

https://zeromanual.com/wiki/FST_Platform/12V_Battery

I suppose that does make sense. As long as the 12V battery can turn on the contactor in order to charge itself, then yeah that would work. Since we know that GEN3 cellular modules run off 12V battery, then it would make perfect sense that the rest of the MBB monitoring circuits would run off of that as well.

[SwampNut]

According to the unofficial manual it periodically charges the 12V battery even when the bike is keyed off.

Which unfortunately I've found to be wrong or at least out of date sometimes...  And sort of related, it would be nice if the cell module could do things like remotely control charging.  It seems like all you get is state and location, and nothing more?  Or did I miss something?