Battery Saver / Capacity / Life (dashcam Installation)

[ukcal]

Hi all,

A while ago I discussed wiring dashcams into my car. As of today, I have finished setting up two Mobius actioncams (for front and back) and got all of the wiring ready. Literally, all I need to do now is connect wires and run them round the car.

Now, I want to add them to a continuous 12V circuit (using one of the unused 12V circuits in the passenger glovebox) as I have set them up for motion detect. This way they will record any activity while my car is parked (bearing in mind my car got hit whilst parked last month...).

My question is, does my Fiesta have a battery saver function in that it would automatically cut off supply to unnecessary electrics whilst sat turned off, should the drain from the idling dashcams become too great? Alternatively, having read that the current draw from each camera is likely to be 300 mA or less, assuming the battery had a capacity of 40Ah, I could, theoretically, get approximately over 66 hours on a full battery (40 / 0.6 = 66.666...).

If I was really conservative and said I could have them in use for 50 hours before needing to drive (and recharge the battery), would this be an accurate statement?

I'd rather not go to drive my car and find it needs jump-starting all because I have plenty of footage of pedestrians and cars driving past!

Cheers, guys!

Oh, and here is how the wiring has been achieved...

[Eatonm112]

Although the battery on your car is rated at 40Ah that is when its brand new and fully charged once they get older they loose their capacity as they degrade over time , also temperature has an effect on how log they last too.

Your calculation of 50 hours would mean that your battery would not have enough capacity to start your engine based on the max current of the devices you are connecting up. If they are in stand by until motion near you car is detected you may be fine but that does depend on how busy the area is where you leave the car parked up.

As for what circuit to connect to I would connect to the fuse that powers the radio as that will stay live all the time. Some circuits will time out on your car like the interior light but I think that's about it. I would suggest getting the owners hand book out and finding the correct fuse for the radio as if it was me I wouldn't want to be connecting anything to the ABS, Airbag or engine management circuits just for piece of mind more than anything else.

[Eatonm112]

In addition you may want to look at adding a small secondary battery to run the cameras if you find that your current solution flattens the main battery too quickly Or get a voltage sensing cut off relay to stop the cameras dropping the main battery voltage below 11.5 volts.

[ukcal]

Although the battery on your car is rated at 40Ah that is when its brand new and fully charged once they get older they loose their capacity as they degrade over time , also temperature has an effect on how log they last too.

Your calculation of 50 hours would mean that your battery would not have enough capacity to start your engine based on the max current of the devices you are connecting up. If they are in stand by until motion near you car is detected you may be fine but that does depend on how busy the area is where you leave the car parked up.

As for what circuit to connect to I would connect to the fuse that powers the radio as that will stay live all the time. Some circuits will time out on your car like the interior light but I think that's about it. I would suggest getting the owners hand book out and finding the correct fuse for the radio as if it was me I wouldn't want to be connecting anything to the ABS, Airbag or engine management circuits just for piece of mind more than anything else.

Well, by being conservative and saying 50 hours (instead of 66.666... by calculation), I'm assuming there would be power available still to turn the car on.

If I choose to connect them to a circuit that turns off when the car is off (ignition circuit I have my subwoofer remote wired into also), I could rely on their internal batteries to motion sense for a period of time afterwards until they die. Still, that won't cover me by the end of a day at work!

[CharlieUK]

I also have a dashcam in my car and I too have had this problem. I was interested in checking how much power the engine needed to crank the engine, so I placed a multimeter over the 12v socket. In the spaces of a second the voltage dropped from 13.5v to 0.06v. Granted that is on a 8 year old battery. But due to the camera it has gone flat 3 times now!!

Now as I'm a bit of a geek, I connected a 12v 10w solar panel, which powers around the 0.83a mark. To the roof of my car. I haven't tried it through the glass yet, but it stops the battery from dying. I haven't got any pictures but here's a link

http://pages.ebay.com/link/?nav=item.view&alt=web&id=261967436175&globalID=EBAY-GB

http://pages.ebay.com/link/?nav=item.view&alt=web&id=251969367087&globalID=EBAY-GB

Or you could look into buying a flexible solar panel and fitting it to your car permanent.

Sent from my iPad using Ford OC

[ukcal]

Okay, that is an interesting idea to look into! I'm going to connect them today to the ignition circuit so that they lose power when the car is off. Once, with the help of you lot, I find a good way to provide continuous power, I will just change where they are wired into!

Thanks for the help so far!