Is it possible to draw too much 12V, etc. power?

[missylc21601]

I am heading out on my first long-term trip soon and have a question about drawing 12V and other power while I'm driving.

My Highlander has 2 12V ports and 4 USB ports for charging. If I'm using all of these outlets at the same time while driving, is the car battery still charging? Do I need to calculate how much power is being drawn by each device? For instance, I have a Jackery 240 I'll be charging, an inverter that with 2 AC receptacles I may use to charge a laptop and camera battery, plus USB-charged devices like my phone, a small fan, lights, bluetooth speaker, etc. 

The car does have a shut-off feature in case something is plugged in that may blow a fuse, so maybe that would prevent drawing too much power?

I don't foresee needing to have all of these devices plugged in all the time, but on the off-chance I need to draw that much power, am I handicapping my car battery?

 

[user 423]

As long as your battery and charging system are in good condition, it will not be a problem.

Can you quote your owner's manual or link to info about the shutoff feature? Surely it wouldn't do that while you're driving down the road.

(Do you mean a cutoff for the Jackery or the car's electrical system?)

 

[missylc21601]

To clarify, the shut-off feature cuts power to whatever is being charged. Not the car's battery. Thanks!

 

[bullfrog]

Some computer controlled charging systems do limit charging to increase fuel mileage, in particular I remember someone having difficulty keeping batteries up after adding a house battery and some accessories. You might try searching previous posts about high performance alternators as i believe the initial question of the post was about why it didn't work.

 

[MrAlvinDude]

Hmmm...    It seems that the Toyota Highlander has a power save feature, where the engine shuts off, when stopped at a red light.

Perhaps this is why there is also an automatic shut-off function, for your 12V ports (and maybe this shuts off the USB ports at the same time).


The whole system is most likely geared towards ensuring that there is always enough power in the battery, to re-start the engine - while you are stopped at a red light.
While you are stopped, the engine is off, and will thus not be charging the starter battery. If there are several stop-and-go events in short succession (can easily happen in city traffic), then the designers may have chosen to 'sacrifice' some user comforts, in order to maintain low gas mileage, even in the cities.

But, at a push of a button, you can always eliminate the gas-saving-at-red-lights (or other city stop-and-go traffic).
When you eliminate/pause the gas saving at traffic stops, your starter battery is being charged at all times, as well as anything plugged into your 12V ports.


So if this is the functionality of you car, then you can simply adjust its 'city-gas-saving-feature', in order to prioritize your charging of things.


Did I understand the question, and the functions of your car, correctly?

 

[LargeMarge]

...drawing 12V and other power while I'm driving.

My Highlander has 2 12V ports and 4 USB ports...using all of these outlets at the same time while driving, is the car battery still charging?...
The car does have a shut-off feature in case something is plugged in that may blow a fuse...on the off-chance I need to draw that much power, am I handicapping my car battery?

.
In your Kluger, you mention 12v and other power.
Generally, a USB-style telephone charger is limited to a couple-three amps?
A cigar lighter outlet is limited to ten amps?
Each circuit is protected by a fuse or circuit-breaker.
Attempting to exceed the circuit rating results in a blown fuse or a tripping circuit-breaker.

Suggestions:
* verify your outlets have fuses, not circuit-breakers.
.
As we know, any fuse is engineered to protect the wire down-stream from it.
If the draw exceeds the fuse capacity, the fuse can heat enough to melt its innerds, and this, breaks the circuit.
Better the fuse heats and melts than melting wires.
This's its function, and it is happy to do it.
.
Although similar in purpose, a circuit-breaker has a different operation.
Slower to notice, thus slower to react, after feeling an over-draw, a circuit-breaker breaks the circuit using a mechanical switch.
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I want to see your shut-off device up-stream of each fuse or circuit-breaker.
Now, I am usually all-for redundancy.
However, a device protecting the protector sounds more like a stereotypical Cherman over-engineering.
Your Orientals tend to be straightforward in their schematics.
.
To a your questions:
* 'yes' to the first q,
* 'no' to the second q.
.
An aside:
If we were discussing a Brit vehicle from the post-war years -- Brits were in a lot of wars, so 'post-war' covers a lot of territory -- all bets are off.
Many adventurers in Brit vehicles carry an extra fork on their adventures -- and because it is a Brit vehicle, any attempt at any journey of any length qualifies under the 'adventure' heading.
.
An extra fork, for a surprise visitor at supper?
Nay nay!
The extra dining apparatus is sacrificial, a way to jumper around fried sections of wire.
But... wait!
Wires do not fry, wires are protected by fuses! and circuit-breakers!
Maybe in most normal universes.
Based on my experience, post-war Brit vehicles operate only unwillingly in our universe, and are perpetually pulled back molecule-by-molecule into their home, a place few can imagine.
.
And fewer still venture into.
Apparently, after crossing the elusive border into Brit vehicle universe, in all of recorded history, no one returned to our bastion of rationality.
.
Well, some did, but most prefer to not discuss it.
Do you ever wonder why that is?

 

[user 16179]

.
Well, some did, but most prefer to not discuss it.
Do you ever wonder why that is?

Does all this have anything to do with the fact the Brits drink warm beer because they have Lucas refrigerators?

 

[AmargosaWayne]

Brits used to use the chassis to carry positive voltage. Something about corrosion buildup in damp air on a negative ground point.

Lucas headlamp switches are three way, ON, OFF, and FLICKER.

 

[Spaceman Spiff]

My Highlander has 2 12V ports and 4 USB ports for charging. If I'm using all of these outlets at the same time while driving, is the car battery still charging?

2 x 12V cigar plug outlet, 10A max = 20A
4 x USB ports, less than 5A max = 20A
Basic Highlander alternator = 150A

I don't foresee needing to have all of these devices plugged in all the time, but on the off-chance I need to draw that much power, am I handicapping my car battery?

If you drive more than 15 minutes you should have no problem keeping the battery charged.
I wouldn't charge the Jackery or camera battery unless driving. USB usually draw less than 2A. I've run a small USB fan all night off my truck battery with no noticeable effect.