What Cutoff Voltage to Use?

[unrecognized88]

Hello all,

New to the world of dash cams and recently purchased the A129 Duo for my car and my wife's car due to some car break in at our apartment garage. Luckily, we were not hit this time, but it prompted me to look at ways to try and protect ourselves. I will be hardwiring both cameras with Viofo's 3 wire hardwire kit and using Sandisk High Endurance 256gb cards, but am not sure what configuration I need as far as voltage setting goes.

My wife's car is a 2014 Lexus ES300h. Completely stock car with no modifications.

My car is a 1998 Lexus GS400. I'm not sure if the following is relevant, but per the ClubLexus forums, I should have "13.5v at idle w/normal electrical loads on, 14.1v to 14.0v w/light load and this drops to about 12.9v w/heavy loads such as high beams on/rear defrost/fan on full/radio up. Normal functioning charging system will read 13.5v to 14.5v." I have a viper alarm, double din screen, and a 12" sub in the trunk that I rarely ever turn up anymore. Fan setting is on lowest setting with AC always on. I don't remember when I last replaced my battery, but I am thinking it's probably about 2-3 years old?

Both of our weekday commutes are the same:
Weekday:
Commute to work: 15 min
Park in work garage: 9 hours
Commute to home: 20 min
Park in apartment garage overnight: 15 hours

On the weekend, we take her car, but my car is parked the whole time:
Parked Friday at 4:30 PM until Monday at 6:30 AM (62 hours)

1. With this information, what voltage cutoff should each car be at?
2. Is there a way to ensure my camera stays on over the weekend?
3. Should I also run the original Viofo (non hardwire) power cable down to the driverside footwell and hide an external battery pack under the seat?

• I would basically have 3 cables hanging from the headliner - one would be the hardwire power cable for daily use, one would be the original cable connected to battery pack for weekend use, and the rear camera cable.

Thank you in advanced for any help!

 

[Nigel]

Assuming that your cars both have AGM batteries, which I guess they do, set the cutoff to 11.8 volts, otherwise 12.2 volts.

You are not driving enough to keep the camera going all weekend, to do that you would need a large USB battery pack charged in the house, but you are probably driving enough for an AGM battery to keep going during the week, a non-AGM car battery would probably cut out around dawn.

 

[unrecognized88]

Assuming that your cars both have AGM batteries, which I guess they do, set the cutoff to 11.8 volts, otherwise 12.2 volts.

You are not driving enough to keep the camera going all weekend, to do that you would need a large USB battery pack charged in the house, but you are probably driving enough for an AGM battery to keep going during the week, a non-AGM car battery would probably cut out around dawn.

Thanks, Nigel!

I do have a 10,000 mah external battery pack that I could hook it up to on the weekend. Would this be enough, or should I get an Anker 20,000 mah pack? In order to do this, I would also have to use the original Viofo power cable, correct? Basically use Viofor hardwire cable on weekdays and then switch to Viofo original cable for weekend use?

 

[SawMaster]

Welcome to DCT @unrecognized88
There's a good chart explaining battery voltage HERE on this site. But what you need to understand more is that with your short drives your car battery isn't going to ever be at 100% charge, as the last 5%-10% of charging takes around an hour's driving or more. And with 9 hour parking times daily you're pushing things well into the accelerated battery wear zone or possibly even a no-start condition

So you're going to need something extra like a powerbank to run your cams. The automatic devices like the Cellink Neo and B124 expansion kit won't be able to recharge during your short drives either, so you're looking at needing to manually recharge them at home daily while a second unit is working in the car. Alternately you could get a shop to install a second battery and charging isolater such as RV's use but that will be expensive and doubled with 2 cars It's not hard to get into the habit of swapping powerbanks out daily so that's what I'd recommend as your best approach.

Should you decide tio give it a try with simply hardwiring into the cars, Nigel's advice above is good. Experimenting will show you how much parking time you'll get.

Phil

 

[SawMaster]

You can enter parking mode manually on the weekend when you swap to the powerbank.

Phil

 

[Nigel]

Thanks, Nigel!

I do have a 10,000 mah external battery pack that I could hook it up to on the weekend. Would this be enough, or should I get an Anker 20,000 mah pack? In order to do this, I would also have to use the original Viofo power cable, correct? Basically use Viofor hardwire cable on weekdays and then switch to Viofo original cable for weekend use?

The A129 Duo with both cameras recording will use about 18,000 mAh per 24 hours, so a daily swap with a fully charged 20,000 mAh powerbank will keep it going, although hardly worth the effort unless you have a serious problem that really needs 24/7 monitoring, you are only going to miss Saturday evening and Sunday.

Yes, use the original long Viofo cable that was intended for the cigar socket charger, not the short computer data cable, the short one doesn't carry enough power.

While Sawmaster's comment on lead acid batteries is correct, I think you will be OK with an AGM battery since they charge a lot faster and your cars will have decent alternators, also most AGM batteries are OK with being discharged to 11.8 volts, it will still wear them out faster than without the dashcam, but shouldn't be a problem.

 

[SawMaster]

Are we sure it's AGM? I don't have time to research that but it could work out if it is.

Phil

 

[Nigel]

Are we sure it's AGM? I don't have time to research that but it could work out if it is.

Phil

Generally any car with a stop-start system has an AGM battery, unless it is using lithium hybrid power, I am only guessing these Lexi qualify...

 

[unrecognized88]

A search of the lexus forums yielded this:

98-05 GS: https://www.clublexus.com/forums/gs...th-size-34-battery-on-gs-and-other-lexus.html

13+ ES300h (hybrid) : https://www.clublexus.com/forums/es-6th-gen-2013-2018/858099-battery-es300h.html

To summarize your suggestions: I will set both cars at 11.8. Then for my car I will run the original cable as well and manually disconnect from hardwire and connect to a 20,000mah batterypack for the weekend. It's a bit more work, but I want to try to deter the thieves if/when they come back. I have another year on my lease, so I need to stay vigilant.

 

[SawMaster]

That sounds like a good approach And nice to work with someone who already understands much of what we've discussed As long as your batteries aren't on the way out I think you'll be fine, and you can always change cut-off voltage settings later if need be.

When doing the install, be sure you're behind the airbags and not crossing in front of them anywhere. You might also want to run the rear cable temporarily in the planned location and check for radio reception and key-fob unlocking function. Occasionally a rear cam will interfere with these requiring a cable relocation to solve.

Phil

 

[unrecognized88]

Lol thanks, but to be honest, I'm still fuzzy on the voltage stuff. I looked at the chart you linked and I'm a little confused about this comment:

Lead Acid start batteries typically found it vehicles should not be routinely deep cycled or that will reduce the life of the battery. Hence, if you never want to deep cycle your battery the cutoff needs to be 80% or 90%. This equates to a voltage cut-off of around 12.4V.

Setting my cutoff at 11.8V sounds like it would be too low according to the above suggestion? Or am I just reading this completely wrong?

Other information you might need: Temperature in Houston can get up to 100s in the summer, but we are both parked in those large, covered, corporate office-type garages at home and at work.

 

[kamkar]

Yes it might be a good idea to do a test run of the rear camera cable before you commit 100% to putting it somewhere, for this dry test dangling the cable in front of airbags should be fine.

I read somewhere if you are installing a dual system, it is often a good idea to not run the power wire and rear camera wire to the same side, so if your power wire go from the middle of the windscreen to the Left A pillar and down there, then the rear camera should go to the Right side and out back over there.
But if thats true then you cant install any cable permanent before you have figured out what route are best for your rear camera cable.

 

[kamkar]

As long as you dont have direct sun on the car in the summer, parking guard should be fine, but if things get too hot, like so many other things it will just shut off itself in self preservation.

 

[kamkar]

wire routing can give issues with key fob range - build in GPS navigation and satellite or DAB radio signal strength.

None are a issue for me as i don't listen to radio or have build in GPS navigation in my cheap little car, and key fob range dont bother me, if it is bad i can do the old fashioned key in door lock, i am lazy but not that lazy.

 

[unrecognized88]

Thanks Kamkar1! I watched quite a few installation videos, so I will be doing that. It's going to be a bit difficult on my car because the rear passeanger door is stuck shut lol. I'll figure something out though.

 

[kamkar]

Yes 11.8 volts are too low for lead acid batteries, there i would not go below 12.2, but for a deep cycle battery like AGM batteries it should be fine

 

[Nigel]

Setting my cutoff at 11.8V sounds like it would be too low according to the above suggestion? Or am I just reading this completely wrong?

11.8 is very low for a standard lead acid battery, but there are different types which operate at slightly different voltages.

For an AGM battery 11.8 is OK, and will result in it being able to charge fairly rapidly giving a good parking mode time.

It is recommended to occasionally charge it to 100% to keep the plates clean, maybe every 3 months, either by a full charge from a battery charger, or by at least 6 hours driving with no parking mode use.

 

[kamkar]

yeah it seem like many modern smart cars can be a little too smart some times, my Suzuki car are a 2012 and one of their smallest models, so its not that smart.
And i can install a dual system in the car in 30 minutes, but i also know my car very well from installing many cameras over the years.
With a newer and smarter car i would have to use considerable more time to make sure i don't create more problems for myself than i like to.
So i would probably put front camera on wind screen and the rear camera back there, and then experiment with "loose" wires taped / zip tied to stuff along the planned route to see what if anything get affected by that solution.

In the end you might have to make a compromise if your car are sensitive, cuz changing to another brand of dashcam i don't think will make significant changes.

 

[unrecognized88]

Ah "lead acid" vs "AGM" was what I was missing. So I got a little curious and ran out to my car and this is the battery I have:

Bosch Premium Performance Battery Group, Size 24 | 9998137 | Pep Boys

www.pepboys.com

It has a sticker that says shipped March 2018, so its about 2 years old. Don't remember when I got it, but as I am typing this, I remembered that I keep the receipt in my car, so I am facepalming myself right now.

 

[Nigel]

Ah "lead acid" vs "AGM" was what I was missing. So I got a little curious and ran out to my car and this is the battery I have:

Bosch Premium Performance Battery Group, Size 24 | 9998137 | Pep Boys

www.pepboys.com

It has a sticker that says shipped March 2018, so its about 2 years old. Don't remember when I got it, but as I am typing this, I remembered that I keep the receipt in my car, so I am facepalming myself right now.

I think I would go to 12.0 volts for that one, 12.2 if you want a long life, but that will reduce your record time considerably.