Parking Mode - Any "plug and play" 24h+ battery solution ?

[Montecristo]

Hello to all,

before I describe the specifics of my - humble - ask to you, I hope you will kindly bear with me on all the inaccuracies or mistakes I may write (I am as noob as it gets regarding electricity).
I also read beforehand several threads which contain all plenty of much instructive information...But I am not in capacity to translate them into a solution for my case.

1) Context

• a) I have purchased a 70MAI A800S + OEM hardwire kit
• b) I wish to have a parking mode connected to an auxillary battery/energy storage unit (Target : at least 24hours autonomy)
• c) It must allow me to easily switch a depleted energy storage unit for a fully charged one. Assuming a 24h autonomy, I could thus come and swap the battery once per day which is fine for me.
• d) And for the lack of originality, I am looking for a price-savvy solution. If required some DIY would be more than welcome (always an occasion to learn something)

2) Thoughts

• a) It seems A800S needs to be hardwired for the parking mode to work. Is there a way to hardwire a classical (i.e. non dashcam) powerbank to the A800S ? The OEM hardwire has a 12V-24V input, and usual powerbanks seem to have a 5V output so I infer that is already one matter to deal with.
• b) If so, which powerbank capacity for a 24hour autonomy?
• c) Would a voltage cutoff still be needed for a powerbank ?
• d) If that is possible, I was thinking of : hardwiring the ACC to an ACC fuse, and the "rest" to the powerbank. But I have no idea how to consider wiring ground in this "hybrid" case.
• e) I would place it all in the trunk. I would come replace every day the powerbank with a full one, charge the other one, etc.
• (Sorry to be such a noob and jump on the "Powerbanks are cheap, why not use them ?" )

Many thanks in advance for all the enlightening help you can provide,
Kind regards,
Montecristo.

 

[Montecristo]

Additional thought regarding 2.a) above :
Stumbled across an interesting video regarding USB-C "power delivery" (PD) protocol (video link below).

Apparently, the beauty of USB-C PD is that, with a rather simple "trigger board" (example link below), you can modulate the tension.
The videos shows a 12V router being fed by a 5V powerbank + trigger board set to 12V.

• 2.a.1) How about wiring the VCC and ground to a USB-C trigger board set at 12V ? Would that be a solution ?
• 2.a.2) How would this behave (most notably : powerbank and camera reliability, temperature) ?
• 2.c) Question regarding need for voltage cutoff remains.

- Video Link :

- Example trigger board link : https://www.amazon.com/gp/B07T6LPP9W

Thank you!
M

 

[kamkar]

If i was to use long duration parking guard, i would put a AGM battery in my car just for the dashcam, and then have it insulated from the car lead acid battery so the car can always start.
This i feel are more easy to manage VS some lithium battery that necessitate a charger for such a battery

But that little trigger board are nifty

 

[Montecristo]

Hello,
thank you Kamkar for your feedback. Sorry for my delay, I took time collecting some more data, especially by reading through the forum again.

Given my specifics, I feel like trying two options out of curiosity :

• USB PD powerbank + Trigger board set to 12V, in order to "fool" the 70mai hardwiring transformer
• Auxiliary battery (preferrably AGM) + battery isolator

1) Could you confirm the wirings in each option are correct as per drawing attached ?
2) As regards safety, would you recommend fusing and if so, could you tell me where to put fuse(s) and at which amp ?
3) As regards safety (continued), how shall I select the correct cables for connecting the AUX battery ?
4) As regards the Powerbank option, one thing that bugs me is that the drawing (if correct) does not allow for using battery source while driving. Is there any workaround other than using a passthrough powerbank connected to, say, the cigarette lighter (as I saw in a forum thread) ?


I well agree that the battery + isolator seems the more robust solution...Just feel curious about experimenting the powerbank and USB trigger I have already ordered the components on "All-in-Express, awaiting delivery to try it on.

Thank you very much for your help,
M.

 

[Nigel]

1) Could you confirm the wirings in each option are correct as per drawing attached ?

The one with the AGM battery is good.
The one with the powerbank has a problem with the GND connection.

2) As regards safety, would you recommend fusing and if so, could you tell me where to put fuse(s) and at which amp ?

The fuse is only to protect the wiring in the case of a short circuit because the cable insulation has been damaged, maybe by rubbing against sharp metal for a couple of years. It should go as close to the source of power as possible, so normally we use a fuse tap into the fusebox, but for the AGM battery you would use an inline fuse holder, within about 10cm of the battery. For the powerbank, a fuse is not necessary since the powerbank has a built in current limit.

The fuse should be rated no higher than the cable, so if you are using 5A cable, you should use a 5A or less fuse. The cameras will use 1A at most, so the minimum fuse size is 2A.

3) As regards safety (continued), how shall I select the correct cables for connecting the AUX battery ?

2A cable minimum for the connection from battery to hardwire kit, normal to use 5A or 7.5A since it is more robust, less likely to get damaged.

For connecting the battery to the isolator and isolator to the main battery, you don't have a current limiter, and AGM batteries can take a lot of charging current, so you could check the specification for your battery to see how much current it will take, or use cable that matches the maximum output of the alternator, or maybe use something a bit smaller and check to see how hot the cable gets when charging an "empty" battery, in this case the charging current will be limited by the resistance of the cable, so as long as the cable isn't overheating then it is safe, but without knowing the battery and alternator specification, the result can't be predicted.

4) As regards the Powerbank option, one thing that bugs me is that the drawing (if correct) does not allow for using battery source while driving.

There are a lot of issues getting this to work, the biggest being the changeover from one power source to another without causing the camera to shutdown due to seeing a low voltage. Ideally you would use a powerbank with passthrough, but most USB PD powerbanks will not do this, or if they do then they will turn off for a second or two while switching into charging mode, which will shutdown the camera causing a reboot and loss of recording for maybe 10 seconds total.

Is there any workaround other than using a passthrough powerbank connected to, say, the cigarette lighter (as I saw in a forum thread) ?

With the USB PD powerbanks, it is normally OK to connect the output of your trigger board in parallel with another source. Since it is 12V, you could connect the ACC directly to the 12V output of the trigger board (via a diode so that your trigger board doesn't supply power to the ACC circuit when ACC is off!), then you have power when ACC is on, and it will switch to powerbank power when ACC is off, unfortunately many powerbanks will take some time to switch out of charging mode, which will cause the camera to reboot and miss a few seconds. While this may work, it is impossible to say that it is definitely OK without knowing the internal circuits of the powerbank, so you try it at your own risk and at the risk of destroying the powerbank! Keep a fire extinguisher handy, although very unlikely to be needed!

Apparently, the beauty of USB-C PD is that, with a rather simple "trigger board" (example link below), you can modulate the tension.
The videos shows a 12V router being fed by a 5V powerbank + trigger board set to 12V.

That is a nice board, I have used one.

2.a.2) How would this behave (most notably : powerbank and camera reliability, temperature) ?

Don't put the powerbank in the sun, or anywhere that gets excessively hot - mount it near the floor, not overhead.

2.c) Question regarding need for voltage cutoff remains.

The powerbank will turn off when it is empty, so the voltage cutoff in the hardwire kit becomes unused, not a problem.

2.a.1) How about wiring the VCC and ground to a USB-C trigger board set at 12V ? Would that be a solution ?

The big problem here is that you have more than 1 ground, 1 comes from the powerbank, and another from the car. With a normal powerbank I do not recommend connecting these together as the internal circuit of the powerbank often puts them at different voltages, if you connect them then the powerbank current limiting will not work, however the USB PD powerbanks are normally OK. Do it at your own risk and don't leave it unattended while testing, but it will probably be OK with a PD powerbank.


Most powerbanks charge rather slowly, they are good if you need to change them regularly because you aren't driving every day, but for normal use the AGM battery via an isolator is a much simpler and more reliable option that will charge far more rapidly. If you are going to use a powerbank, consider one with "UPS" functionality which will sort all the problems but comes at a price, look at Zendure which also has some with very rapid charge rates for a powerbank.

 

[kamkar]

I think the battery have to be on the always on wire, the ACC wire in modern hard wire kits are so to say just the trigger wire so the camera know go go to parking mode or come out of parking mode.

There are the dedicated dashcam power packs, that are in essence "just" a regular power pack, these can be daisy chained to increase capacity

 

[Montecristo]

Wow, many thanks for your help Nigel, Kamkar...Especially for answering each of my questions with such accuracy !

Most powerbanks charge rather slowly, they are good if you need to change them regularly because you aren't driving every day

That would be exactly my case : the car currently sits just on the street in front of my place up to 3/4 days. I can easily switch a power source every day, charge the empty one at home and so forth. Come what may, well, I guess I could do this with 2 small motorcycle AGM (say 10 Ah) batteries...But I must admit it would be intellectually frustrating not to find a solution with powerbanks.

Since it is 12V, you could connect the ACC directly to the 12V output of the trigger board (via a diode so that your trigger board doesn't supply power to the ACC circuit when ACC is off!)

My apologies for making you rehash Nigel, but this is where my lack of knowlegde kicks-in...I guess the "output" corresponds to side of the trigger which connects to the hardwiring ? If so, does the drawing below adequately represents what you said ? Then, could you give a reference example of a diode which could work ? Also, just wondering if the ACC current flowing to the trigger output would not "enter" the trigger and damage it ?

The one with the powerbank has a problem with the GND connection.

The big problem here is that you have more than 1 ground, 1 comes from the powerbank, and another from the car. With a normal powerbank I do not recommend connecting these together

Would there be any "correct" wiring alternative which could solve this issue, or is it an inevitable issue with this option (to test at my own peril) ?


Many, many thanks !
M.

 

[Nigel]

That would be exactly my case : the car currently sits just on the street in front of my place up to 3/4 days. I can easily switch a power source every day, charge the empty one at home and so forth. Come what may, well, I guess I could do this with 2 small motorcycle AGM (say 10 Ah) batteries...But I must admit it would be intellectually frustrating not to find a solution with powerbanks.

You only need a 20,000mAh powerbank, they are small and light, and will power most dual cameras for 24 hours, far more convenient than an AGM if you are swapping them regularly.

My apologies for making you rehash Nigel, but this is where my lack of knowlegde kicks-in...I guess the "output" corresponds to side of the trigger which connects to the hardwiring ? If so, does the drawing below adequately represents what you said ?

I would expect that to work. Although I would have drawn it with the diode connected to the red, makes no actual difference, but the power is logically being supplied to the red.

Then, could you give a reference example of a diode which could work ?

I suggest a 2A or greater rectifier diode such as a 1N58xx Schottky diode.

Also, just wondering if the ACC current flowing to the trigger output would not "enter" the trigger and damage it ?

Without fully understanding the circuit in the trigger, and maybe also the powerbank, this can't be answered. However, I would be very surprised if there was any issue with doing that other than possibly putting an insignificant drain on the car battery.

You could of course put another diode on the output of the trigger so that power could not flow into the trigger output. (With the negative sides of the diodes connected together.)

Like I said above, I don't recommend it for a normal 5V USB powerbank since there are often issues with the grounds not being the same.

Would there be any "correct" wiring alternative which could solve this issue, or is it an inevitable issue with this option (to test at my own peril) ?

You could use a dual pole relay, so that you swap both + and GND connections from one source to the other, but doing that is likely to trigger a shutdown of the camera when switching in both directions and adds complexity and reliability issues which are probably not needed.

 

[kamkar]

I am no electronics guy, i did have electronics in night school in about 7 grade or so, but as i wasent just allowed to solder together all kinds of kits like i did a light show kit at home, but i was also supposed to learn something, well that sent me strait into "lock down " which is what i call what my brain do if you try to force anything upon it.
Also why school was such a trauma for me.
Trick me by making things interesting, and my brain will jump into vacuum cleaner mode and just suck up information all on its own,,,,,,, though retention will still be a issue.
I cant go full nerd on anything, even if it is something i really like, so with some things i just call myself a dedicated user.

 

[mentadent]

Are there any power banks that still output while charging? I've tried a few brands and they all have a problem for this situation, in that they need the button pressed to turn them on when they go from empty.

 

[Montecristo]

Hi gentlemen, hope you had a pleasant weekend.

Nigel, Thank you so very much for your time ! I have ordered the various components, I will see how this turns out. I will pass through the GND issue - to be honest it is well above my grasp...The good thing is that the powerbank connection can be easily tested home first. Well, I guess the batt isolator too, as soon as I get a hold on two small AGM batteries.

I would have drawn it with the diode connected to the red

Just for the sake of understanding, could you confirm if the amended diode connection scheme below corresponds to what you had in mind ?

1N58xx Schottky diode

On another forum thread here, a rectifier diode was used to "adjust" the low voltage cutoff of a hardwiring kit (typically the 70mai could fit the case).
Wouldn't such a diode generate a voltage cut which could create an issue and trigger a cutoff inadvertendly ? Maybe the specs of the diode can allow to choose one with a minimal voltage cut?
I apologize if my questions do not make much sense given my lack of knowledge.

Trick me by making things interesting, and my brain will jump into vacuum cleaner mode and just suck up information all on its own,,,,,,, though retention will still be a issue

You should copyright this phrase...Story of my life especially the last part. That and the mystery of the socks-eating washing machine.

Are there any power banks that still output while charging?

Yes, it is called a powerbank "with passthrough". However, there may be limitations to consider (starting with what Nigel said previously) as well as claims of dubious quality. I guess some more search and review-reading would give better insight. There is a forum thread in which it was discussed connecting such powerbank to the cigarette lighter (which is ACC+) and then he camera to the powerbank.

Cheers,
M.

 

[Nigel]

Just for the sake of understanding, could you confirm if the amended diode connection scheme below corresponds to what you had in mind ?

Yes, that makes sense.

Note that you may need to connect the black HWK wire to car GND as well as the trigger to make it operate reliably.

In case you haven't come across the instructions for that module:

Test of yzxStudio ZY12PDS PD trigger

On another forum thread here, a rectifier diode was used to "adjust" the low voltage cutoff of a hardwiring kit (typically the 70mai could fit the case).
Wouldn't such a diode generate a voltage cut which could create an issue and trigger a cutoff inadvertendly ? Maybe the specs of the diode can allow to choose one with a minimal voltage cut?

Different diodes give a different voltage drops, the Schottky diode was recommended because that has the smallest voltage drop available of commonly available diodes, typically 0.2 volts.

Yes, it can affect the cut off, however since you have red and yellow connected together, the low voltage cutoff is disabled.

I apologize if my questions do not make much sense given my lack of knowledge.

When it comes to electronics, it is a very good idea to think about things and ask questions; if you do things without understanding then you often get a cloud of smoke and nothing works!

Are there any power banks that still output while charging? I've tried a few brands and they all have a problem for this situation, in that they need the button pressed to turn them on when they go from empty.

Many do to some extent, but most seem to cause issues at engine startup. As I said above, look and Zendure and their UPS feature if you want a problem free powerbank, only issue then is that you do have to pay a lot more than for the basic cheap powerbanks, but then it is going to get a lot of use so a decent one is probably a good investment.

 

[Montecristo]

Thank you for your help Nigel. I learnt a lot those last few days thanks to you guys.
Now I can start to look at "datasheet" without finding only hieroglyphs.

That website is great! Seems to be several articles and projects which I am going to read.
Since it is Danish, I can sense the Kamkar connection here

since you have red and yellow connected together, the low voltage cutoff is disabled.

Could you tell me why connecting red and yellow together causes that ?

 

[jonat]

Have you considered a Cellink Neo or something similar? This is a LFP battery that charges while your vehicle is on, and then runs the cam in parking mode when the ignition is off. It can easily run most dashcams for 24 hours, and you can connect a second battery for longer runtime. I have one in my car, and it needs no attention once installed. Not cheap, though.

 

[Montecristo]

Have you considered a Cellink Neo or something similar?

Yes, and there is no denying dashcam batteries have their place for the reasons you mentioned. I just opened this thread to assess the relevance of a cheaper, DIY alternative. I definitely am not the first and I can feel I will not be the last ha!

 

[Nigel]

Could you tell me why connecting red and yellow together causes that ?

That is just how it is programmed to work!

I think it is a sensible assumption that if you have the ignition (ACC) on, then you want it recording, and you don't want it to stop recording if the voltage level drops, such as when you turn the engine over, or when you turn your headlights and windscreen demisters on at the same time, or if you have an Alfa Romeo then every time you wind the windows down!

That website is great! Seems to be several articles and projects which I am going to read.
Since it is Danish, I can sense the Kamkar connection here

I don't think there is any connection, apart from them both being from Denmark...
There are some good and intelligent people in Denmark!
Apparently far more than in France, but it might just be that the French often refuse to speak/write in English so don't come here, while the Danes are very happy to communicate with the the non-French world

 

[Montecristo]

And the few French who try to communicate in English ask some bizarre questions when it comes to electronics ! But more seriously, it’s also a given that the Nordic countries are much more proficient at speaking English and the French are still lagging behind.

I don't think there is any connection, apart from them both being from Denmark...

Ha yes, was just jesting about the coincidence, I reckon the Danes have been much helpful to me

 

[jokiin]

Apparently far more than in France, but it might just be that the French often refuse to speak/write in English so don't come here, while the Danes are very happy to communicate with the the non-French world

the French seem to like to stick to their own corner of the internet

Dashcam France.fr - Accueil

Dashcam France.fr - Accueil

www.dashcam-france.fr

 

[Montecristo]

Hello to all,
Sorry for not having given any update before, as I could not move forward without receiving the different parts and elements I had ordered from Aliexpress.
I do hope you are faring well and heatwaves are not burning you to a crisp for the fellows on the Northern hemisphere.

Just received the last parts less than an hour ago : the USB PD powerbank from Baseus, as well as a diode isolator for the alternative "Aux Battery" scheme.



As you can see, this is the setup of a guy who doesn't know crap about electronics. But "boi got heart".
I also bought a USB dongle tester, but I forgot to buy a female / female USB cord, so sadly I cannot plug it between the powerbank and the trigger board.

1) First test, the powerbank + ZY12PDS Trigger + 70mai Hardwire kit

- It works neat ! By setting the trigger board to 12V, you can see the dashcam being on and you can play with the parking mode by plugging/unplugging the ACC from the + trigger end.
- There is an internal V/A reader on the powerbank, though not accurate (1 decimal).
- I first tested the parking mode. You guys already said it all in the forum. I found the parking mode not consistent, even erratic sometimes. You can shake it strongly and sometimes it triggers parking recording, sometimes not.
- When parking recording is triggered, the recording starts 5 seconds after the shaking (in line with the front cam status led turning green), and records 1 minute (led then turns off).


2) Next steps :
- I am going to test the autonomy of the battery today, see how long it lasts as well as its apparent condition (heat most notably).
- I will try to add the diode + Battery on the ACC wire, to see if the load from battery can indeed be switched off during that time (i.e. car battery taking over).


What do you think of all that? Perhaps would you have any suggestion on interesting stuff or test to do ?

Kind regards,
Montecristo.

 

[Outbacknomad]

Perhaps would you have any suggestion on interesting stuff or test to do ?

Another option is a DC-DC charger (two 9amp chargers in parallel stacked on top of each other in my case) and two of my four 26AH gel batteries under a seat. One could switch the load to the starter battery when the car is running but if the setup has enough charging capacity it is not worth the fiddling around.