VIOFO Prototype Hardwire Kit - Test & Review

[Panzer Platform]

During testing of EGEN dash cam battery packs (@BlackboxMyCar PowerCell 8 & BlackVue B-130X) I discovered the battery packs continue to deliver power down to 10.9 Volts, (indicated by Cellink Neo APP).



The @viofo hardwire kit has 4 settings for Low Voltage Cutoff (LVC) protection;
12.4V
12.2V
12.0V
11.8V
This means when the lowest LVC setting is used, (11.8V) the hardwire kit will shut off power to the dash cam prematurely, and prevent the battery pack from delivering its full capacity (96Wh).
In July 2023 @rcg530 and myself requested a prototype hardwire kit with the capability to disable the LVC, so we could test how much remaining capacity is left in the battery pack, (and how much additional parking mode run time it would provide).
In December 2023 we both received our prototype hardwire kits.
Special thanks to Viofo for making, and sending them out.
They appear identical to “regular” HK4 hardwire kits with one difference.
The 12.4V setting disables the LVC.
After numerous parking mode testing sessions I have determined the prototype hardwire kit allows the PC8 to deliver an “extra” 3Wh of capacity that was previously unutilized.
How much additional parking mode run time is 3Wh?
90 Minutes: A119 Mini 2
36 Minutes: A229 Pro 2-CH Rear
Based on these test results I would like to make a recommendation for Viofo to “upgrade” their hardwire kits with the capability to disable LVC, so users of dash cam battery packs can utilize the full capacity of the battery pack, and have longer parking mode run times.

Additional Note:
BlackVue, Thinkware, and other dash cams utilizing 12 Volt barrel connector power connections have the capability to disable LVC using their respective smartphone APPs.
Implementing this feature will bring Viofo “up to standard”.
Yo Robert, @rcg530 can I get some “peer review”?

 

[rcg530]

Back in December 2023, I ran two BlackboxMyCar PowerCell 8 battery pack discharge tests using a VIOFO A229 Pro 3Ch dash camera in low bitrate parking mode.

The first test was with the HK4 low voltage cutoff (LVC) feature set to 11.8V/23.6V. I charged the PowerCell 8 to a 100% charge level. I connected my Fluke 117 multimeter to the dash camera constant battery power and ground wires running from the PowerCell 8 to the dash camera. I connected the HK4 to the PowerCell 8 and powered up the dash camera. I then turned off the input charging power to the PowerCell 8 which turns off the output accessory power sent to the HK4. I ran the low bitrate parking mode battery drain test to confirm the HK4 would in fact turn off the power to the dash camera when it dipped below 11.8V. The HK4 did turn off the power to the dash camera when the PowerCell 8 constant battery power level reached 11.78V.

I recharged the PowerCell 8 again to prepare for test 2. The prototype VIOFO HK4 hardwire kit has what is labeled as the "12.4V/24.8V" low voltage cutoff switch position which has been converted to be the "Disable LVC" position. I executed the same test steps as test 1, but this time I wanted to see how long the PowerCell 8 would continue to power the dash camera after the output constant battery voltage dropped bellow 11.8V. The PowerCell 8's output constant power voltage level decreased at a somewhat quick pace after reaching the 11.8V level. I found that the PowerCell 8 did not turn off the output constant battery power until the voltage level reached 10.29V, which is well below the believed 10.9V minimum output voltage level for the PowerCell 8.

You can see in the three pictures that the PowerCell 8's output constant battery voltage level dipped just below 11.8V at 23:30:31. It continued to provide power to the HK4 until just after 23:49:31. By 23:50:00, the PowerCell 8 had turned off the output constant battery power. Powering a VIOFO A229 Pro 3CH in low bitrate parking mode, the PowerCell 8 was able to provide power for an additional 19 minutes with the LVC feature disabled in the HK4.

 

[Panzer Platform]

Right on, thank you for the confirmation.
Do you think Viofo should “upgrade” their hardwire kits with the capability to disable LVC to extend parking mode run time when used with a dash cam battery pack?

 

[rcg530]

Do you think Viofo should “upgrade” their hardwire kits with the capability to disable LVC to extend parking mode run time when used with a dash cam battery pack?

I'm in favor of having VIOFO replacing the 12.4V/24.8V LVC slide switch setting with the "Disable LVC" setting. The 12.4V/24.8V LVC setting is an almost worthless voltage value since most slightly less than new vehicle batteries will have their voltage level float down to the 12.5V to 12.3V range shortly after the alternator stops charging them. Why keep a 12.4V/24.8V setting that almost never realistically gets used when you can put in its place one that would get used by the portion of the user base that uses dash camera battery packs to power the VIOFO hardwire kit.

 

[Panzer Platform]

Well there you have it Viofo.
The NorCal Test Team is in agreement. lol
Can you implement this upgrade to all future hardwire kits?
Will this modification add unjust manufacturing cost, or complexity?
I guess you will have to make new stickers changing 12.4V to “LVC Off”.
And update the website, and instruction manual for the hardwire kits.
Should we have @Nigel come in here to see what he thinks? lol

 

[Nigel]

Should we have @Nigel come in here to see what he thinks? lol

I would actually prefer that they remove the 12.4 setting, move all the others along one position to the right. and add an extra low setting on the left.

The question then is what should the extra low setting be?
10.8V would solve the problem with the battery packs:

I discovered the battery packs continue to deliver power down to 10.9 Volts, (indicated by Cellink Neo APP).

and it would also ensure that if it was used on a standard car battery, it would not kill that battery completely, might not start the engine any more, but it could be recharged and work again, while if the HWK keeps taking power down to 0.0V then the battery will be destroyed.

I would accept 10.0V, since that is the point a lead acid battery is completely empty. 10.0V will work fine with the battery packs.
Also, I think it should be higher than the point that the voltage regulator in the HWK which regulates the 5V output gives up, which is probably about 9.5V.

I suspect 10.0V may be too low for a lead acid battery to still power a dashcam, so a little higher might be sensible, so lets go for 10.8V.

...

 

[Panzer Platform]

I regret rubbing the Genie's lamp. lol
We need LVC completely disabled, just like BlackVue & Thinkware, and all the other Korean brands.

 

[mentadent]

I want this feature. I have two Powercore power banks and it would probably make them run longer.

 

[Nigel]

I regret rubbing the Genie's lamp. lol
We need LVC completely disabled, just like BlackVue & Thinkware, and all the other Korean brands.

It is not really disabled though, going less than 10V just means that things will go wrong when either the battery can't supply enough power, or the voltage regulator can't regulate any more and it keeps trying to work but can't. You want it to turn off reliably when the battery is empty and not turn on again until there is some power back in the battery, if you run until things go wrong then that switch to keep it turned off will fail and it will keep trying to start recording, failing, maybe corrupt the SD card in the process... A clean turn off at 10.8V would be better.

 

[Panzer Platform]

It is not really disabled though, going less than 10V just means that things will go wrong when either the battery can't supply enough power, or the voltage regulator can't regulate any more and it keeps trying to work but can't. You want it to turn off reliably when the battery is empty and not turn on again until there is some power back in the battery, if you run until things go wrong then that switch to keep it turned off will fail and it will keep trying to start recording, failing, maybe corrupt the SD card in the process... A clean turn off at 10.8V would be better.

I disagree, we’ll see what @rcg530 says about this.

 

[Panzer Platform]

I want this feature.

I was hoping you’d stop by. lol
Do you know how to measure how much Wh capacity is left in your battery pack after the Viofo hardwire kit shuts off at 11.8V?

 

[Nigel]

I disagree, we’ll see what @rcg530 says about this.

For your power bank, it is OK to disable the LVC completely, because the power bank does the turn off/on, it is also OK to set the LVC at 10.8V, it will make no difference because the power bank will turn off first.

The issue is if you use that setting for either a lead acid battery, or a LiPo4 battery pack without a low voltage cut off, a 10.8V cutoff would be much more useful, instead of buying a very expensive dashcam power bank, you could just buy a LiPo4 12V battery, connect the hardwire kit, and connect the battery to a charging relay (as used for camping). Probably better to use a proper charger, but it would be a cheap solution with potentially a very large capacity.

 

[Nigel]

Do you know how to measure how much Wh capacity is left in your battery pack after the Viofo hardwire kit shuts off at 11.8V?

Probably best to just time how much longer it records for with the LVC disabled and then multiply the extra hours by how many W the camera uses.

The actual time will depend on the load, so testing using any other load than the dashcam is not going to give the same result.

 

[Panzer Platform]

you could just buy a LiPo4 12V battery, connect the hardwire kit,

Incorrect.

Probably best to just time how much longer it records for with the LVC disabled and then multiply the extra hours by how many W the camera uses.

The actual time will depend on the load, so testing using any other load than the dashcam is not going to give the same result.

Incorrect.

 

[mentadent]

I was hoping you’d stop by. lol
Do you know how to measure how much Wh capacity is left in your battery pack after the Viofo hardwire kit shuts off at 11.8V?

lol. No, how should I do it?
I have a Powercore.

 

[Panzer Platform]

lol. No, how should I do it?
I have a Powercore.

There's a couple different ways you can do it.
Can you temporarily remove one of your Powercores for "bench testing"?
Do you have a basic Voltmeter?
Do you have a "home charger" for the Powercore?

 

[mentadent]

I have a voltmeter, and I can remove it. I don't have home charger.

 

[Panzer Platform]

I don't have home charger.

=(

 

[safedrivesolutions]

I think there is some bad suggestions here. Removing 12.4 volts is a bad suggestion. I think redesigning the cable for 5 switches where 5th switch is a bypass would make more sense. Or having it so the case comes apart with 2 phillips screws and you can select a bypass jumper inside makes way more sense.

 

[Panzer Platform]

I think redesigning the cable for 5 switches where 5th switch is a bypass would make more sense.

I agree with you 100%
Adding a 5th setting was my first choice, but it will most likely add considerable manufacturing cost / complexity so I’m willing to swap 12.4V with OFF.