Rear power socket questions.

ashleyg82v702001 · Post by **ashleyg82v702001** » 11 Sep 2021, 11:29

Hello folks.
I have a question regarding the rear 12v power supply socket..

A little background on what I want to do to explain the need for this information:
I want to build a power hub that is separate from the car for camping so we are not using the power durin the night.

Using this

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I want to essentially create a power station for in the tent to run a cooler fridge tent lights and chargers for phones / cameras.
My question is, is the rear sockets power regulated or will it recharge the leisure battery if I connect it through the socket whilst the car is running?

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Many thanks for your help

Post by **cn90** » 11 Sep 2021, 11:42

I'd not use the car battery for that purpose, the battery can run down overnight.

Better approach: if your battery is > 4 yrs old, buy a new battery and install it.
Save the old battery for camping, charge it at home first (buy a charger), this way it does not interfere with the car's main battery...

For "fridge", best approach is ice and cooler bc the fridge typically consumes a lot of juice...

ashleyg82v702001 · Post by **ashleyg82v702001** » 11 Sep 2021, 11:57

You've miss-understood my question..
I don't want to use the car battery overnight. I want to use an external battery. I'm asking about output of the rear socket to recharge that whilst driving durin the day

darylrobert · Post by **darylrobert** » 12 Sep 2021, 01:12

i also may not fully understand your question. I have a 2nd small lead acid battery in my XC70 its called a UPS uninterrupted power supply (USA made-cant remember name) and fits into that space below the factory outlet, i can take a pick if you like. Connected to the cars main battery It charges when the car is running.
I have my radio and dashcam connected to it, i had the situation where my camera would boot up then switch off when i started the car. The UPS fixed that issue and can now run my radio without worry and also it keeps powered up during startup and its really handy because the reverse camera image remains during startup as i often start the car in reverse gear.

I tested that factory outlet and it stays powered for hours, if i were to use it i would consider putting a timer or voltage dependant relay on it.

I also have a mains power supply in the trunk running of main battery for laptop etc, i need to park on a hill when i use that.

Edit. my bro-inlaw has a solar power setup he uses for camping, it charges a car 12v batt during the day however you live in UK so solar power may not work.

edit 2 also check what AMP rating your alternator is before adding extra loads like batteries. from memory mine is 160amp

ashleyg82v702001 · Post by **ashleyg82v702001** » 12 Sep 2021, 01:35

OK let me re-woord the question forget the car until i mention it

,

I want to create a leisure battery box to use in my tent to power phone chargers, digital camera charger and lighting with a fridge output.

IF I plug it into the rear 12v power socket in the car the morning after use during the night (once we are using the car so alternator is running) will it recharge? Or does the 12v have a voltage regulator?
IF I'm the morning

darylrobert · Post by **darylrobert** » 12 Sep 2021, 01:48

yes it will charge the 2nd battery, rate will depend on your alt. A car isnt actually 12v its between 10v-14.5v

darylrobert · Post by **darylrobert** » 12 Sep 2021, 01:53

Personally i wouldnt use that outlet, i would be more inclined to run heavier wires directly from the battery (with fuses)

ashleyg82v702001 · Post by **ashleyg82v702001** » 12 Sep 2021, 02:34

In that case is there a way to stop the depleted leisure battery from flattening the car battery?
Without having to throw a switch or something everytime I stop the car?
I figure someone has done something before like this being such a versatile vehicle

darylrobert · Post by **darylrobert** » 12 Sep 2021, 02:39

sorry i just realised what you wrote, i dont recommend connecting a 2nd car 12v battery directly to that outlet without a current limiting charger (trickle charger) or UPS electronics as i suggested. Unless as i suggest you heavier wires with a charger or match the same size battery cables that volvo use directly to the cars batttery.

Any UPS or charger should stop charging automatically when you stop the car

darylrobert · Post by **darylrobert** » 12 Sep 2021, 02:42

this is what i have installed for a few years in my car https://www.powerstream.com/DC-UPS-1212.htm i highly recommend it

Important factors charge is limited to 3amp (this maybe within the volvo outlet limit), charging stops when alt stops, power is cut if 2nd batt gets too low.