Hardwiring and Battery issues

lau_cam

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Hello,

I bought an A129 Duo for my 2019 Mazda 3 and have been running into issues with the car battery ever since I installed the Dashcam. One night I had the car in ACC mode on for about 40 minutes. when I was ready to leave the car had trouble turning over once but after I turned the car off completely then back on the engine started. Then a week later I had the radio on only thinking I had learned from my mistake of having ACC mode on however when I was ready to leave 30 minutes later the car wouldn't start. I had to get a boost and seconds later the car would start but the engine light came on. The next day I unplugged the wire that connects the front and rear camera and the engine light went away. Is there any solution to my problem that doesn't involve removing the hardwire?
 

runtohell121

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The main question is how was it hardwired? 2019-current Mazda3 interior fuse box is always on; meaning the dash cam would draw power constantly even while the car is off. If it was hardwired through the engine bay fuse box, that shouldn't be an issue.

When I owned the 2020 Mazda3 (sold it 2 months ago), I went with OBD option from Thinkware because knowing that hardwire will require going through the engine bay/firewall.
 

Outbacknomad

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I have seen quite a few cars with flat batteries. Firstly, as mentioned above, how was it wired in?

Modern cars are stuffed full of electronics, everytime you open the door the car will go through the start up process even if you do not actually start the car.

Cars have far too small starter battery to save weight. Probably only 60AH on your car. It's a joke!

A car radio these days in not a 1 watt AM radio. Look up the fuses, 2 x 40amps for the middle of the range system in my car. 30 minutes running the radio, a few short trips, a battery a few years old etc (look at the actual date of manufacture of the battery), is asking for problems.

I got sick of jump starting cars and installed an Anderson plug to make life easier. People get a bit nervous in the outback when they have a flat battery 1000km from help and no mobile phone reception.

I also have another Anderson plug on my auxiliary batteries so I quickly jump start from my back up batteries as well.
_MG_2504 (2).jpg

Do not wire cameras and other accessories into the starter battery and then use them with the engine off. It will all end up in tears.
 

Mtrev

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The current draw from the camera will be a drop in the ocean compared to the draw from all the consumers powered with just acc on, 30-40 mins is a recipe for disaster.
I would have expected that if the battery was low, the cars power management would have turned off the radio to preserve starting but maybe that’s not the case on mazda’s.
 

SawMaster

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Do not wire cameras and other accessories into the starter battery and then use them with the engine off. It will all end up in tears.
Then I guess the millions of people who do this without problems don't exist. There are limitations to what you can draw from the car battery, and any draw will shorten it's service life, but if it's done carefully that loss will range from negligible to tolerable. Dashcams use less than 2A (under 24 W) for full-time recording, and some parking modes cut that in about half. Thus it's almost never an issue to get 2-3 hours parking mode use from a car battery in good condition, and a large battery can well exceed that amount of time. You may lose a couple months service life from your battery doing this but nothing worse will happen.

The problem is that you must never allow your battery to drop below about 50% charge- and certainly never let it go dead- or it's capacity and service life will be greatly shortened. As few as 4-5 instances of a dead battery can destroy it, even if it began as brand new and fully charged. Hardwire kits monitor the battery voltage and turn the cam off when it reaches the cut-off voltage you've set or that it's designed for if it's not adjustable. It's safe to use a HWK voltage setting of 12.2V in almost any car. If that causes problems then you're battery likely needs replacement. A setting of 12.0V may be OK with larger or newer batteries but nothing lower. Many non-adjustable HWK's do not cut off till 11.8V or 11.6V which is far too low. Adjustable HWK's generally offer a 12.4V setting, and that's where to start. If you get enough recording time leave it there; if you want more set it lower.

The OP's problem here seems to be that their HWK is not shutting off properly- perhaps not even entering parking mode. That could be caused by it not being wired in properly or a faulty HWK. It would seem that uif it is activating the 'check engine' light it's not on the best circuit. And/or the wire going to 'IGN' may not be tied into a correctly operating circuit. It's hard to know without checking things with a voltmeter or test light, and even that can lead to misleading results with many of today;'s cars using CANBUS or computer controlled power schemes. A car owner's forum for your specific car make and model may get you some advice on which fuses to tap into. Only a few cars seem to not have any way to use a normally installed HWK- usually German cars but I'm sure there's others.

One other thing might be happening here. Based on what I've read from people who seem knowledgable, if you start a Viofo cam with HWK recording normally while the battery voltage is below the setting on the HWK it may not cut off at all. Other HWK's may behave similarly, I don't know. It's not a situation you much encounter but it's a possibility. Digital multi-meters (DMM) are very cheap these days and all but the worst are accurate enough to use for working with dashcams. I'd suggest the OP get one and check things out to find another circuit to use for the 'BAT' wire of the HWK, and to be sure the other wire sees power ONLY when the ignition switch is on- not when it's in "ACC' position. And I'd have them take the car to a shop where the battery and charging system can be tested. From that maybe we can help solve the problem.

Phil
 

Outbacknomad

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Lead acid batteries tend to have about 300 cycles to 80% discharge, but it is not going to drop off a cliff. Typically the battery will be discharged a small percentage and the car will charge it up. If you calculate the total life KWh of the battery (60AH x 12 x 300 x 80%) there is not a lot of difference to a 30% discharge in total KWh life of the battery. Again it is not going to drop off a cliff.

If you drain the battery 80% once every 3 months over the 4 year life of the battery it's not going to hurt it. But the sooner you can charge up the battery the better. Lead acid batteries prefer to be kept fully charged. Ideally with a smart charger, depending on the make, Bluetooth with your phone so you can see precisely what state of change the battery is at.

My starter motor needs 238amps according to my clampmeter, for a second. So the total watts of this 1 second is not a lot energy. Then after 30 seconds the car typically charges at 80amps with 130amp alternator.

When the car is off, have cameras, phone, fridge etc running off auxiliary Battery.
 
OP
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lau_cam

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The main question is how was it hardwired? 2019-current Mazda3 interior fuse box is always on; meaning the dash cam would draw power constantly even while the car is off. If it was hardwired through the engine bay fuse box, that shouldn't be an issue.

When I owned the 2020 Mazda3 (sold it 2 months ago), I went with OBD option from Thinkware because knowing that hardwire will require going through the engine bay/firewall.
It was hardwired through the interior fuse box and the mechanic used wires he had on site because he said that he had wires to do it. So now that this problem has started I’m thinking it could be the wiring because I checked the battery after letting the car sit for 24+ hours and the battery still have decent charge in it.
 
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lau_cam

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I have seen quite a few cars with flat batteries. Firstly, as mentioned above, how was it wired in?

Modern cars are stuffed full of electronics, everytime you open the door the car will go through the start up process even if you do not actually start the car.

Cars have far too small starter battery to save weight. Probably only 60AH on your car. It's a joke!

A car radio these days in not a 1 watt AM radio. Look up the fuses, 2 x 40amps for the middle of the range system in my car. 30 minutes running the radio, a few short trips, a battery a few years old etc (look at the actual date of manufacture of the battery), is asking for problems.

I got sick of jump starting cars and installed an Anderson plug to make life easier. People get a bit nervous in the outback when they have a flat battery 1000km from help and no mobile phone reception.

I also have another Anderson plug on my auxiliary batteries so I quickly jump start from my back up batteries as well.
View attachment 56801

Do not wire cameras and other accessories into the starter battery and then use them with the engine off. It will all end up in tears.
Through the interior fuse box, also appreciate the input and knowledge
 
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lau_cam

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Then I guess the millions of people who do this without problems don't exist. There are limitations to what you can draw from the car battery, and any draw will shorten it's service life, but if it's done carefully that loss will range from negligible to tolerable. Dashcams use less than 2A (under 24 W) for full-time recording, and some parking modes cut that in about half. Thus it's almost never an issue to get 2-3 hours parking mode use from a car battery in good condition, and a large battery can well exceed that amount of time. You may lose a couple months service life from your battery doing this but nothing worse will happen.

The problem is that you must never allow your battery to drop below about 50% charge- and certainly never let it go dead- or it's capacity and service life will be greatly shortened. As few as 4-5 instances of a dead battery can destroy it, even if it began as brand new and fully charged. Hardwire kits monitor the battery voltage and turn the cam off when it reaches the cut-off voltage you've set or that it's designed for if it's not adjustable. It's safe to use a HWK voltage setting of 12.2V in almost any car. If that causes problems then you're battery likely needs replacement. A setting of 12.0V may be OK with larger or newer batteries but nothing lower. Many non-adjustable HWK's do not cut off till 11.8V or 11.6V which is far too low. Adjustable HWK's generally offer a 12.4V setting, and that's where to start. If you get enough recording time leave it there; if you want more set it lower.

The OP's problem here seems to be that their HWK is not shutting off properly- perhaps not even entering parking mode. That could be caused by it not being wired in properly or a faulty HWK. It would seem that uif it is activating the 'check engine' light it's not on the best circuit. And/or the wire going to 'IGN' may not be tied into a correctly operating circuit. It's hard to know without checking things with a voltmeter or test light, and even that can lead to misleading results with many of today;'s cars using CANBUS or computer controlled power schemes. A car owner's forum for your specific car make and model may get you some advice on which fuses to tap into. Only a few cars seem to not have any way to use a normally installed HWK- usually German cars but I'm sure there's others.

One other thing might be happening here. Based on what I've read from people who seem knowledgable, if you start a Viofo cam with HWK recording normally while the battery voltage is below the setting on the HWK it may not cut off at all. Other HWK's may behave similarly, I don't know. It's not a situation you much encounter but it's a possibility. Digital multi-meters (DMM) are very cheap these days and all but the worst are accurate enough to use for working with dashcams. I'd suggest the OP get one and check things out to find another circuit to use for the 'BAT' wire of the HWK, and to be sure the other wire sees power ONLY when the ignition switch is on- not when it's in "ACC' position. And I'd have them take the car to a shop where the battery and charging system can be tested. From that maybe we can help solve the problem.

Phil
Thanks Phil! Appreciate it
 
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