Dashcam install - Fuse question

[Allegiance]

Hi All,

I'm going to follow these instructions to install a Blackvue DR-750S 2CH Dashcam - Dash Cam Install Tutorial – Volkswagen MK7 Golf – AutoInstruct

Question is, with the fuse tap they use, they don't mention the amperage of the add-on fuse, but assume a 10A would be fine?

Also, does anyone know which size fuse tap would work?

Double Blade Fuse Socket Wire Tap | Jaycar Electronics

https://www.jaycar.com.au/double-micro-blade-fuse-socket-wire-tap/p/SF5130

https://www.jaycar.com.au/double-mini-blade-fuse-socket-wire-tap/p/SF5125

Thanks!

[Guest001]

2 amp would be enough but I usually put a 5 in

Depends on which fuses you are going to use Pull the one you want and see before buying DONT use AIRBAG or ABS fuses

[DV52]

@Allegiance: Hi. selecting the fuse for the dash-cam is really about the quantity of power you will allow to be dissipated into the device in a fault - specifically, fuse selection for car situations (it's called "grading") isn't about current limiting for overload protection. Certainly, knowledge of the maximum normal operating current is important because the fuse must be able to not-melt when the device is not experiencing a fault!

So - the specification for the DR750S-2CH is that it draws an average of 4.2W at 12V, when GPS and Wi-Fi are ON. This is 350 mAmp. Conservatively, you could assume reasonably that under peak conditions, the maximum electrical current for normal operation could be as high as 1 Amp (for a short time) - maybe. The general rule-of-thumb for vehicle applications is that the current rating of a fuse is typically de-rated 25% for operation at 25 ̊C to avoid nuisance blowing. So for a 1 Amp device, a appropriate fuse of 1.33 Amps is sufficient (nominally, let's say 1.5 Amps).

Of course, you can opt for larger amperage fuses if you want - but be aware that the "cost" of increasing the fuse size is that the power dissipation when a fault occurs becomes greater by the square of the increased rating. So - for example, installing a 3 Amp fuse (i.e. doubling the fuse size) will quadruple the power that is dissipated into the fault (all other electrical conditions remaining unaltered).

So, increasing fuse size beyond the "optimal grading" value means greater damage inside the device when a fault occurs - it's all about balance

Don

[Guest001]

Its also hard to buy blade fuses of less than 5 amps. Have managed to find some 2's but seem to be rare.

Best way for a dashcam is to use the original cable which has the correct 2 amp fuse in its plug.

Use a fuse tap into a ciggy socket like this and plug the cable into it. Then it doesnt really matter whats its the second fuse position within reason

As well as that for BV it helps with 5V cameras as it puts it through the built in stepdown in the ciggy plug