List of "typical" electrical loads in a modern car

[MetroMPG]

We often talk about modding the electrical/charging system to reduce engine load. I happened across a quality source of power demands from various vehicle systems, and thought I would post it.

The list below summarizes the major subsystems (and loads) of the automotive electrical/electronic content of a modern (2006) automobile in the following categories:

• Engine management
• Multimedia and heating, ventilation, and air conditioning (HVAC)
• Body electronics
• Chassis electrification
• Lighting (exterior and interior)
• Future systems

Engine Management            Power (W)
Fuel Pumps Injectors         135
Ignition System              60
Electronic Throttle Sys.     60
Sensors a Actuators          110
Solenoids & Relays           20
Subtotal Engine              385
Amps @ 14.2V                 27.11

 Chassis Electrification      Power (W)
Electric assist steering     300
ABS brake system             200
Air suspension valves        50
Air compressor               500
Subtotal Chassis             1050
Amps @ 14.2V                 73.94

 Charging System              Power (W)
Alternator                   3000
Battery (80 Ah)              1000
Starter motor                2200

 Multimedia & HVAC            Power (W)
High end audio sys.          300
Navigation and GPS           150
Driver information display   30
Cabin climate valves         75
Blower motor + ECU           370
Subtotal Cabin Sys.          925
Amps @ 14.2V                 65.14

 Lighting (Exterior & Interior) Power (W)
Headlamps (2)                120
Running/Park lights (4)      130
Turn signal lamps            130
Center high mount stop        65
Back-up, interior, license    45
Subtotal lighting            490
Amps @ 14.2V                 34.51

 Body Electrical              Power(W)
Power Windows (4)            560
Power Door Locks (4)         200
Wipers and washers           140
Heated backlight             500
Power seats (2)              460
Subtotal Body Sys.           1860
Amps @ 14.2V                 130.99

 Future Systems              Power(W)
DVD and in-seat displays    
MicroJMild-hybrid functions    
Active suspension    
Frontyrear radar    
Obstacle detection & Airbags    
Active cruise control    
Total Electrical/Electronics    4710

Source of the figures is an article about the increasing complexity & demands on vehicle electrical systems and how to mitgate this.



See more:

Accessory overload threatens auto power budgets: Part 1, burgeoning loads and transients | Automotive DesignLine

[some_other_dave]

I don't know of too many vehicles with air suspension, plus GPS & Nav, plus electric power steering and brakes, plus all-electric everything...

That said, the basic point is still valid; there's a whole lot of electrical stuff in today's cars!! That's one more reason why I drive yesterday's.

-soD

[Daox]

Thats a great list Metro. I always knew constant draw from an engine was around 25-30A. This proves it.

[MetroMPG]

Ha! Maybe YOUR engine!

I'd still like to stick an ammeter on the Flea and get a true reading. I'll buy you a donut if it's more than 25A.

[Peter7307]

Another item not mentioned ( Unless I missed it !) is some auto transmissions have an electronic control module which is always active.

Pete.

[Tygen1]

I stuck an ampmeter on mine once. At idle with no accesories on, it was around 20amp's. At idle with absolutely everything that could be turned on, on, it was around 42amp's. A/C at max, doors open, high beam head lights, brakes, hazards, rear defrost, stereo cranked etc... I've just got an Escort, so it doesn't have many accesories at all.

[Piwoslaw]

Originally Posted by Tygen1

I stuck an ampmeter on mine once. At idle with no accesories on, it was around 20amp's. At idle with absolutely everything that could be turned on, on, it was around 42amp's. A/C at max, doors open, high beam head lights, brakes, hazards, rear defrost, stereo cranked etc... I've just got an Escort, so it doesn't have many accesories at all.

In my car the the low beams, high beams and fog lights are 55W each per bulb. The lows and fogs turn off when the highs are on, so I have 2x55W with high beams vs 4x55W with low beams + fog lamps.

Also, Svietlana has way more electronic gizmos than I need or even want:
- heated side mirrors (turns on with rear window heating),
- rain sensor for the automatic windshield wipers,
- light sensor for the automatic headlights when it gets dark (of course here the lights must be on during the day too),
- electrophotochromic mirror, turns dark when someone shines at you at night,
- FM/GSM/GPS antenna, GPS is always looking for satelites even though I never use it,
- 5 disc CD changer which doesn't work, but is making noises and gets pretty warm after 30 minuts of driving (I'm going to get rid of it soon).

[wagonman76]

A few more I can think of. Many cars of the 90s+ had a body control module.

Power antenna, power headlight motors. Probably not significant but many had them.

Heated backlight, does that mean rear defrost?

Fog/driving lights is a good mention, since many vehicles have those.

[orange4boy]

My Previa van draws 15-20A running without any other loads. I have an ammeter installed. The brake lights used to draw about 8 amps but I switched them to LED and now they don't even show up on the ammeter.

[Sulfuric]

I P&G(lots of engine off coasting) with my 94 Corolla a lot. If I drive at night, with the headlights, brakelights, and the top 3rd brakelight all on, but with all other electrical stuff off, about how long could I coast before I either:

A) Do not have enough power to start my car with the key
B) Have my lights dim to the point that it becomes a safety problem
C) Damage my battery

I have a 550(ah?) battery in relatively good condition, so let's assume 550 as a starting point.