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Discussion Starter · #1 ·
Hey all!

New to the group and soon to take delivery of my second EV (first for family use - MG ZS).

I'm sure this will turn out to be a stupid question but I'm struggling to find the answer... what is used to power the 12v volt outlet in EVs - obviously its not going to be an alternator, so is it drawn directly from the main batteries? The reason I ask is that we plan on doing a lot of family trips this year (restrictions allowing) and would hope to run a 12v fridge, family would be charging phones, laptops, tablets and all the other things a modern family don't seem to be able to live without.

Would this all cause massive drainage, is it possible to simultaneously charge/run multiple items?

Thanks
 

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Zoe Devotee
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There is a DC-DC converter that keeps the 12v topped up from the HV pack.

You can run stuff directly off the 12v when the car is "on" and "ready" a 12v cool box will be fine, but a fridge? Using the USB to keep electronics charged will also be fine but obviously the more you draw from 12v or USB the less range you'll have, but in all honesty you should lose more than a handful of miles if you were maxing the draw for a whole trip.
 

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Discussion Starter · #3 ·
Hey Sandy,

Thanks for that, its eased my anxieties - I actually meant the cool box type (poor choice of word).
 

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Do be careful! Hyundais quote something like 180W from their 12V aux outputs, and some people who have tried taking that have ended up melting the sockets! They really aren't designed to take anything like 15A, even 5A might make me think twice. Tyre pumps probably draw a lot, but tend to only be on for a minute or so.

Another problem is draining the 12V battery, and potentially killing it. Again, Huyndai seem to have gone for the smallest & lightest 12V battery that will get the car started, and even dealers have flattened the batteries just be leaving the driver's door open while doing stuff! Some EVs have a "Utility mode" where the 12V aux stuff is kept topped up from the high voltage battery, or you can just make sure you don't actually turn the car off when using accessories. Your 12V battery needs tender, loving care!!! :)
 

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Discussion Starter · #5 ·
Thanks HandyAndy - I'll be sure to take it easy and do some real world tests, adding items slowly... the cool box is 42w and I think the laptop was 60w so it really doesn't take long to start adding up.
 

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There is a DC-DC converter that keeps the 12v topped up from the HV pack.

You can run stuff directly off the 12v when the car is "on" and "ready" a 12v cool box will be fine, but a fridge? Using the USB to keep electronics charged will also be fine but obviously the more you draw from 12v or USB the less range you'll have, but in all honesty you should lose more than a handful of miles if you were maxing the draw for a whole trip.
I think a laptop would be a problem,,, even in many ICE's !
 

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Discussion Starter · #7 ·
I think a laptop would be a problem,,, even in many ICE's !
Nick

I'm driving an Astra at the moment and have never had an issue charging the laptop, it charges from a little inverter I got from Amazon that goes in the 12v socket.
 

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Nick

I'm driving an Astra at the moment and have never had an issue charging the laptop, it charges from a little inverter I got from Amazon that goes in the 12v socket.
Nick

I'm driving an Astra at the moment and have never had an issue charging the laptop, it charges from a little inverter I got from Amazon that goes in the 12v socket.
I'm guessing your Astra has a big fuse for its cigar lighter! Either that or your charger was really low power ( not enough to run the PC itself?) It's a few years ago now, but charging a hi-spec Sony Laptop from a 12v supply required in excess of 30 Amps!! (Yes, the inverter / charger did get very hot !) Modern laptops having a "solid state" drive rather than a rotating hard-disk would require far less current of course... so perhaps its no longer an issue. My present LG laptop does have an SSD, and its internal battery lasts for 17 hours so I have no real need to ever re-charge it from the car....
 

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Discussion Starter · #9 ·
I'm guessing your Astra has a big fuse for its cigar lighter! Either that or your charger was really low power ( not enough to run the PC itself?)
I have to admit I'm not very technical nor mechanic so I couldn't tell you the fuse etc but the inverter is just a cheap Energiser one (it does get warm but nothing excessive). The battery on my current laptop would last the day but its just became habit really... I come out of a clients home and put the cable in while I drive to the next. I have used the laptop while ot is in the inverter but I assume it is running off the battery rather than the inverter itself.
 

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Hey all!

New to the group and soon to take delivery of my second EV (first for family use - MG ZS).

I'm sure this will turn out to be a stupid question but I'm struggling to find the answer... what is used to power the 12v volt outlet in EVs - obviously its not going to be an alternator, so is it drawn directly from the main batteries? The reason I ask is that we plan on doing a lot of family trips this year (restrictions allowing) and would hope to run a 12v fridge, family would be charging phones, laptops, tablets and all the other things a modern family don't seem to be able to live without.

Would this all cause massive drainage, is it possible to simultaneously charge/run multiple items?

Thanks
Probably a DC to DC buck converter charger would be a better bet than using an inverter and then stepping back down to your laptop charging voltage, read attached


Also replace your 12v battery with the biggest that will fit.
 

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Probably a DC to DC buck converter charger would be a better bet than using an inverter and then stepping back down to your laptop charging voltage, read attached


Also replace your 12v battery with the biggest that will fit.
Check out if your laptop communicates with its charger, see Dell example
 
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