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Discussion Starter #1
Hi Guys,

As I said in my Icebreaker post, I've just installed a dashcam/reversing camera in a Zoe R90. At the moment it is plugged in to the cigarette lighter, but this cuts power shortly after exiting the car (as it should).

The dash cam manufacturer (Auto-vox) makes a fuse tap kit to hardwire the camera so that it can do parking monitoring. It has a 'battery saver' feature that switches off the camera if the car's 12V battery drops below 11.4V. This threshold cannot be changed.

My question is whether that level is too low to avoid causing problems turning on the Zoe. I understand that a flat 12V battery is a nightmare because it unlocks the doors, you can't unlock the charging point etc. Or is 11.4V completely safe because the Zoe obviously doesn't need very high currents to crank an engine?

Alternative is to buy a big USB power pack and charge it every few days, but in my experience anything that needs human intervention ends up not getting done. Hence interest in the hardwire.

Thanks.
 

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Zoe Devotee
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Don't think there is a fuse that stays live that's easily accessible in the fuse box, you might have to hardwire to the battery itself.
 

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Discussion Starter #3
Ah thanks, that was the next question. If that's the case the OBD port I guess is the other option. I soldered one of those onto a female cigarette lighter plug in a Model S for a dashcam, which allows you to keep the in-line fuses in the dashcam etc. The Model S periodically charges the 12V battery from the traction battery even when the car is not plugged in so it's (practically) impossible to discharge it. As I understand the Zoe doesn't do this, so it is possible to flatten the 12V battery without the car doing anything about it.
 

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Co-author of CanZE. Q210 nov 2013
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OBD port (pin 16) stays powered. It is doable to tap it. Fused 15A. 12 volt cutoff I would think is pretty OK.

ZOE seems to charge only when in AUX or switched on state, and maybe while charging. I am building a CanZE Screen to confirm this. I have certainly flattened the battery with the charge plug not fully in (so it certainly wasn't charging), but that state kept most of the computers on, as well as repeated plug locking retries ad infinitum.
 

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Discussion Starter #5
Great, good info. The other solution is to use a Cellink B powerpack or something like that - which would charge from a fuse tap or from the cigarette lighter while driving and then power the dashcam from its battery. The Zoe belongs to my wife so I'm particularly conscious of leaving her in the freezing rain with a flat battery...

On a related note, CanZE looks very interesting. I presume the parasitic load from the OBD dongle doesn't create a battery draining risk in normal use? I think I once flattened a Toyota Auris battery using an OBD dongle and not driving the car for a while.
 

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Discussion Starter #6
One more question - is there a consensus of which fuse it is best to tap for accessory power? I imagine some might cause strange computer errors. For something like the Cellink - they can take up to 7A from a fuse tap, as opposed to 5A from the cigarette lighter. This seems to give the best of both words i.e. no load on car battery when parked, but relatively quick recharging of the power pack when driving. Expensive at £170, but my experience in France is that parking lot bumper cars is a national sport and no one has heard of leaving a note on the windscreen.
 

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Discussion Starter #8
Thanks, yes that's another idea. Didn't realise it was customisable for voltage cut off. From what I've seen it can give you 3-10 hours or so depending on the cut-off and power of the dashcam. Something like the Cellink B would give about 24h, but is a more expensive option. I do like the idea of not interfering with the 12V battery, because a stranded wife is not much fun. Should be safe though with the right cutoff.
 

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Co-author of CanZE. Q210 nov 2013
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I presume the parasitic load from the OBD dongle doesn't create a battery draining risk in normal use?
See Is leaving the dongle in and on harmful? on my thoughts on this (SSP)
One more question - is there a consensus of which fuse it is best to tap for accessory power?
Usually it is F29, see The fuses of the ZOE (SSP again)
parking lot bumper cars
Yes. Nobody gives a hoot it seems, on either car that is!
 

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Play by the king and love is all I bring
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I am watching this thread with interest.
 

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Discussion Starter #11
Thanks for the links yoh-there. The cumulative Zoe knowledge on this site is impressive! I will buy the Cell-link B I think and then wire it into the fuse. Will report back on the time available in parking mode. I can already say that the Auto-vox M6 reversing camera is much better than the built-in one (that I test drove but didn't specify on my own). So to have that and the parking mode will be pretty good value.

One other titbit - the reversing light wire seems to have changed colour relative to the service manual. I needed to tap this to trigger the reversing camera, and it is a white wire on the right hand side at the back. The service manual that was posted on a French site (for retrofitting the parking sensors at a dealership) said it was red. Just in case anyone wanted to do the same thing...
 

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Co-author of CanZE. Q210 nov 2013
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I've bought those batteries in the past. Usually guaranteed for 5 years, but what I would like to know is, how and when does the ZOE charge the 12V battery? An ICE charges the battery the whole time that the engine is running. Does the ZOE charge the 12V battery the whole time that the car is "on", or only when it's plugged in, or something else?
ZOE seems to charge only when in AUX or switched on state, and maybe while charging.
I have made this addition to CanZE (not released yet), and so far the verdict seems to be:
  • whenever the car is awake (LED in the emergency flasher switch in the dash on), it keeps the battery at 13.4 volts. This is the perfect maintenance voltage for a lead acid battery. I couldn't get it down switching on various loads, the DC/DC converter just laughed at me (it can do 1kW, 80 amps!).
  • when the car is charging, the voltage drops to 13.1. I have no good explanation for this, but that is what I see.
  • when the car falls asleep, the 12 volt bus seems to be left alone and the voltage slowly drops off to (in my case) 12.3 volt.
This is all very preliminary and only tested with my 4 year old aux battery, in a charged condition. I have no idea what happens if I discharge it, which won't be easy BTW since nearly all loads are switched off when it dozes off. Seems like I would have to use an external load. In my experience, the car will not top up the battery when somehow it goes low while it is asleep.

Speculation: I suspect when the car finds the aux battery rather empty when it wakes up, it will push it up to 14.2 volt, wait for the charging current to settle, then drop off to 13.5 again.
 
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