12 Volt bed outlet - what can it safely power?

[MakinDoForNow]

Good day

It looks like I will have to do a bit of research on how a hybrid truck with an ignition switch works, to figure out how you can use the engine cycling of and on as needed to support your High Voltage battery.

I do believe you were just using your 12 volt battery but I am not an expert...it just sounds like it as the engine did not cycle on its own.

MTF, once I have time to try and figure this out...

Andy

The hybrid started with foot on brake will start the ice (parked or running on roads) will start the ice when the HVB SOC drops to 30% and turn off the ice when the HVB SOC reaches 40% (using regen current also). The 12v can be recharged through the DCDC converter using the current from ice if running or the HVB if ice is not running. When the 12v becomes over 85-95(?)% charged the cycling of the ice will be about once an hour, maybe less. If you have turned off max idle timer then in 3+ hours the 12v will be charged (I have done this in the past but will normally use my noco g5). If truck is put into accessory mode (without foot on brake at least in push button start model) the dcdc converter will assist the 12v circuit until the HVB SOC drops to 32(+/-)% and pop up screen will ask for ice to be started. Then if ice is not started the usage of HVB will be turned off then 12v circuit will be shut down when 12v when 12v battery save SOC voltage is reached.

Sponsored

 

[MakinDoForNow]

Good day

Okay, I just finished several hours of messing with the truck in the garage...gotta like it!

All in trying to see if 12 volt power is or isn't present if no loads plugged i to the 12 volt ports.

I have used my truck, a 2025 Lariat hybrid that has had all updates that are available for it as the test vehicle, and has a battery that was almost fully charged before beginning.

It has no electrical, battery etc issues that I know of other then the need for using MM's lights tricks to keep the battery topped up.

I used my Klein clamp meter (the clamp portion of it) for the first time (read the manual on operation, again) to read the amperage.

The panel in the back left corner of the box that holds the 120 volt plug was removed for access.

Power applied to 12 volt system

This is after the truck timed out and all 12 volt power was lost.

I clamped/metered the wire leading to the 12 volt power port, turned on and off accessory power and with all 12 volt loads removed prior, the 12 volt port was powered, with nothing plugged in, in the truck. I had to use the DC amperage setting.

When the truck timed out after about 90 minutes, all power was lost in the 12 volt system, as expected and as indicated.

Every trucks operation may vary, and battery charge status will affect operation as well.

Andy

Andy. If you think of it check to see if the 120 volt circuit reads 60 volts between each of the blade plugs separately and the round ground plug (using residential wire colors black to green and white to green). If each leg is 60 volts then this should confirm that the inverter is a split phase inverter. Remember that there is no "true ground" in a vehicle.
ETA=
I remember from my plumbing days having to hammer a ground rod wired to pipe rack when everything was wet into ground to prevent being shocked while running pipe threader.

 

[2024ash]

Good day

Okay, I just finished several hours of messing with the truck in the garage...gotta like it!

All in trying to see if 12 volt power is or isn't present if no loads plugged i to the 12 volt ports.

I have used my truck, a 2025 Lariat hybrid that has had all updates that are available for it as the test vehicle, and has a battery that was almost fully charged before beginning.

It has no electrical, battery etc issues that I know of other then the need for using MM's lights tricks to keep the battery topped up.

I used my Klein clamp meter (the clamp portion of it) for the first time (read the manual on operation, again) to read the amperage.

The panel in the back left corner of the box that holds the 120 volt plug was removed for access.

Power applied to 12 volt system

This is after the truck timed out and all 12 volt power was lost.

I clamped/metered the wire leading to the 12 volt power port, turned on and off accessory power and with all 12 volt loads removed prior, the 12 volt port was powered, with nothing plugged in, in the truck. I had to use the DC amperage setting.

When the truck timed out after about 90 minutes, all power was lost in the 12 volt system, as expected and as indicated.

Every trucks operation may vary, and battery charge status will affect operation as well.

Andy

Thanks for using your time and equipment on this Andy. I'm reading this as your tests confirm the 12v flex bed leads continue to supply power for 90 minutes after powering the vehicle down, even if there is no electrical load present?

 

[SafetyGuy]

Thanks for using your time and equipment on this Andy. I'm reading this as your tests confirm the 12v flex bed leads continue to supply power for 90 minutes after powering the vehicle down, even if there is no electrical load present?

Good morning, @2024ash

Yes, for my truck, which is a 2025 Lariat Hybrid, I have a truck that keeps its 12 volt power "on" for approximately 90 minutes after I have shut it down. I had removed all loads prior to testing.

I used a clamp meter around the 12 volt power point wire in the rear of the truck bed instead of metering, so that I would not accidentally activate the circuit while using it to see if there was voltage being supplied...just on case, and I already had the clamp meter as I had some electrical troubleshooting to do on our camper van.

I also can confirm I had a well charged battery in our Maverick before I began. Not so much after though!


Have a great day,

Andy

 

[SafetyGuy]

Andy. If you think of it check to see if the 120 volt circuit reads 60 volts between each of the blade plugs separately and the round ground plug (using residential wire colors black to green and white to green). If each leg is 60 volts then this should confirm that the inverter is a split phase inverter. Remember that there is no "true ground" in a vehicle.
ETA=
I remember from my plumbing days having to hammer a ground rod wired to pipe rack when everything was wet into ground to prevent being shocked while running pipe threader.

Good morning, @MakinDoForNow

I will try to check that later today if I get a chance...

Wow, you brought back some memories with your plumbing story.

We used to have to also pound a steel rod into the ground, but this was when we would set up a FARP...or Forward Area Refueling Point. Go to the woods, find a big field and set up a helicopter refueling site, prep the bowser, pull out the 100 ft or so of fuel hoses, tactical helicopters land, we refuel them and wave them good bye, pull stakes and move on to the next site.

Had to meter the ground rod to make sure it was effectively dissipating static electricity for the bowser and aircraft, and dry ground sucks for a good "ground'.

Ahh, fond memories of getting it done....and I still love the smell of JP4 in the morning, turni g and burning...JP5 as well, but that is a different set of memories (let's see if anyone here knows where and why JP5 is used as a primary aviation fuel...without Googling it).

Sorry I digressed,

Andy

 

[MaverickDragon]

it seems that those that report having the 12 volt power go off immediately on ignition off, I would meter the rear power port or even the interior power port...it is my thought they are are all on the same circuit and should read the same...none...I would meter both, in case I am incorrect in my thoughts.
Andy

I haven't looked at the wiring diagram either, but I suspect you are right.
That would allow the timer to terminate all accessory power to save the 12 volt battery.
It sounds like you are more interested in resolving this so I'll be on the lookout for what you find.

Rather than the power off unless power is used scenario for the bed plugs being a EB vs Hybrid, or model year difference, I'm thinking it may be due to a keyed vs push to start issue.

IIRC, there are others on this thread who reported the same findings I had - No bed plug power used at KEY off shut down means no bed power on.

Since only the XL has a keyed ignition, that may well be the missing variable.
At least in my case, bed plug power had nothing to do with the battery SOC in my test case.

Perhaps someone else with an XL can provide their results...

 

[MakinDoForNow]

Good morning, @MakinDoForNow

I will try to check that later today if I get a chance...

Wow, you brought back some memories with your plumbing story.

We used to have to also pound a steel rod into the ground, but this was when we would set up a FARP...or Forward Area Refueling Point. Go to the woods, find a big field and set up a helicopter refueling site, prep the bowser, pull out the 100 ft or so of fuel hoses, tactical helicopters land, we refuel them and wave them good bye, pull stakes and move on to the next site.

Had to meter the ground rod to make sure it was effectively dissipating static electricity for the bowser and aircraft, and dry ground sucks for a good "ground'.

Ahh, fond memories of getting it done....and I still love the smell of JP4 in the morning, turni g and burning...JP5 as well, but that is a different set of memories (let's see if anyone here knows where and why JP5 is used as a primary aviation fuel...without Googling it).

Sorry I digressed,

Andy

Good morning @SafetyGuy
Was Forward medic in Nam. 3/4 of time choppers would only get to within 3 feet of ground usually because of terrain. Once about 5 feet to landing rails with wipers clearing windshield of jet fuel leaking from his tanks (15-20? Bullet holes?). Two medics handing troop to medics(?) sitting on rails. Heard on radio chopper made it about 8 mile before running out of fuel. Once we landed in a clearing created with an "oreo bomb" (was told it was bombs chained between steel plates, don't actually know but all trees were laying down for 200-300 feet).

 

[SafetyGuy]

I haven't looked at the wiring diagram either, but I suspect you are right.
That would allow the timer to terminate all accessory power to save the 12 volt battery.
It sounds like you are more interested in resolving this so I'll be on the lookout for what you find.

Rather than the power off unless power is used scenario for the bed plugs being a EB vs Hybrid, or model year difference, I'm thinking it may be due to a keyed vs push to start issue.

IIRC, there are others on this thread who reported the same findings I had - No bed plug power used at KEY off shut down means no bed power on.

Since only the XL has a keyed ignition, that may well be the missing variable.
At least in my case, bed plug power had nothing to do with the battery SOC in my test case.

Perhaps someone else with an XL can provide their results...

Good day

It seemed logical it would all be on one circuit with one fuse, so going with that.

I have taken it as far as I can with my truck, as I have vocalized exactly what my truck is...year, model, hybrid, a fully charged 12 volt battery confirmed, after all my checking it out.

So now anyone with similar truck knows how their truck should operate if it is all working properly.

And I would invite other owners to check their trucks if they are curious, to see if theirs has their 12 volt power points powered after truck shut down and driver door opened and closed...or not.

They should have a multimeter for verifying battery voltage etc.

Then come back and record their findings.

Year 2025
Model Lariat
Hybrid or Ecoboost Hybrid
Push start or button Push
12 volt battery state 12.8 v
All updates carried out Yes
And
Result of their test. My 12 volt power points remain charged for appx 90 minutes after the truck is shut down.

I don't expect a response, as it takes time and work.. most are too busy, which is okay...I have the 2025 lariat hybrid covered if someone else has one...and has questions.

Cheers

Andy

 

[Glen Baker LLC]

I guess, I won't emergency charging any EV owners stranded on the side of the road, from my 120 Outlet in the bed.

 

[SafetyGuy]

Good morning @SafetyGuy
Was Forward medic in Nam. 3/4 of time choppers would only get to within 3 feet of ground usually because of terrain. Once about 5 feet to landing rails with wipers clearing windshield of jet fuel leaking from his tanks (15-20? Bullet holes?). Two medics handing troop to medics(?) sitting on rails. Heard on radio chopper made it about 8 mile before running out of fuel. Once we landed in a clearing created with an "oreo bomb" (was told it was bombs chained between steel plates, don't actually know but all trees were laying down for 200-300 feet).

Good day @MakinDoForNow

Hats off and thank you for your service, and as a medic you had a very important job...helping others that can't help themselves anymore.

I have heard and read about thea type of LZ prep and it makes sense as you have to get as close to the wounded as possible.

I seem to remember the same ordnance being called a Daisy Cutter, but that is just grey matter knowledge...Oreo works for me as it spreads the blast directly outwards to clear the area for a light on skids hovering...close but not catching the skids on anything.

I had a neighbour when we lived in Winnipeg, contankerous old Marine (any other kind?). Did quite a few tours on 'Nam as a Huey Door Gunner, got shot 3 times if I remember correctly. Great guy, we got along so well...he is gone now and I still miss him.

He married a Canadian school teacher when he was stationed at the American Consulate in Winnipeg...that was quite awhile ago already.

He couldn't feel the cold in the winter, only wore shorts all year...too many nerves cut in getting fixed up I imagine.

Sorry, went on a tangent...again.

Nice chatting with you!

Andy

 

[BlueSpec1]

Sounds like the 12V Power Points are operating normally as designed by Ford, just like the HVAC Climate Control. The owner just has to figure out what that is.

Exterior Lighting - System Operation and Component Description
• The BCM load shed strategy is not active (a message is displayed in the instrument cluster, such as Low Battery Features Temporarily Turned Off or Turn Power Off To Save Battery, to indicate that BCM load shed strategy is active).

414-01 Battery, Mounting and Cables Description and Operation
2025 Maverick - Procedure revision date: 02/5/2025

Battery Load Shed
The main purpose of controlling electrical consumption with a load management strategy is to:
• Limit battery discharge
• Monitor the battery charge status

For vehicles with gas engines the alternator is not dimensioned to support all loads in all situations.
In some situations energy has to be drawn from the battery. These are mainly during:
• engine idle
• cold climate with a lot of electrical heating functions active
• warm conditions with the engine cooling fan running
• large transient loads (i.e. EPAS )

For HEV/BEV vehicles, a DC/DC converter control module is not dimensioned to support all loads in all situations.
In some situations, energy has to be drawn from the battery.

Vehicles built before 2025 have a partial load shed strategy.
Vehicles built after 2025 contain the full load shed strategy.

During cold conditions, the charge acceptance of the battery is very low which increases the time needed to recharge the battery.
This means that it can take up to several hours of driving before the battery is recharged.
The electrical consumption control is using Ignition_Status, Remote_Start_Status and EngineStateInternal in order to define the load management strategy during the different operating states of the vehicle.
The BCM is the primary module that is responsible for controlling the load management strategy.
The BCM processes measurements of the system and uses the information for calculations and load prioritization.
The strategy allows drain to occur from the battery. Load Management minimizes the drain by controlling the time and magnitude of the drain that can occur.
The battery drain changes depending on the driving cycle and the types of loads the driver has activated, therefore, the BCM must be able to shut down or reduce the loads if necessary.
The intent of the initial load shed stage, LSHED1, is to reduce electrical loads in a manner that is not noticed by the vehicle operator.

During LSHED1, requests are sent in a prioritized order for the appropriate modules to begin shedding available loads.
In order to prevent customer satisfaction issues, the loads are requested to reduce power consumption with minimum impact to the customer.

The second load shed event, LSHED2, occurs in two stages, SHED2_TRANS and SHED2_CONTIN.
During operation of a vehicle equipped with large transient loads, there are transient peaks for current draw.

The Load Management algorithm reacts to these spikes by using the SHED2_TRANS state.
This state requires all non-critical loads to shed immediately, without customer indication, so that large transient loads can operate normally with little to no adverse impact to the customer.

SHED2_CONTIN is a continuous deactivation of the loads to ensure the vehicle is able to restart once the ignition is turned off.
During SHED2_CONTIN, a message is displayed to the vehicle operator notifying them of the vehicle's charging system status.

Independent of load shed requests, the Load Management control can request boosts to the engine idle speed.
Boosting the engine idle speed allows for increased output of the alternator to deliver more current to the battery.
Idle speed increases are done through network IBoost messages.

The load shed charts provide a general overview of the features available on the vehicle based on the build options.

Load Shed Charts

2025 Lariat Maverick:

Power Point Relay 3
--> F40 20A -> Rear Power Point RH
--> F35 20A -> Rear Power Point LH

Power Point Relay 2
--> F34 20A -> USB Charge Port
--> F139 20A -> Not Used

Power Point Relay 1
--> F33 20A -> Not Used
--> F32 20A -> Power Point Front

2022 - 2024 Maverick:

 

[SafetyGuy]

Andy. If you think of it check to see if the 120 volt circuit reads 60 volts between each of the blade plugs separately and the round ground plug (using residential wire colors black to green and white to green). If each leg is 60 volts then this should confirm that the inverter is a split phase inverter. Remember that there is no "true ground" in a vehicle.
ETA=
I remember from my plumbing days having to hammer a ground rod wired to pipe rack when everything was wet into ground to prevent being shocked while running pipe threader.

Hello again, @MakinDoForNow

So I tried to find out for you but wasn't able to get my meter probes into the bed 120 volt blade openings, they are pretty restrictive.

Please remember my electrical expertise is...not expert!

I tried clamping each of the two wires on the bach side of the plug and put a load on the plug and no joy...that only is for amperage and not what I was going for anyways. But I was curious.

Anyways, it is Canada Day up here and I am just sitting down to watch the Jays and Mets game with my wife...I was listening to the radio play by play so didn't miss anything.

To any and all Canadians, HAPPY CANADA DAY!

And to everyone else, I hope you have a great day as well.

Andy

 

[SafetyGuy]

Sounds like the 12V Power Points are operating normally as designed by Ford, just like the HVAC Climate Control. The owner just has to figure out what that is.

Exterior Lighting - System Operation and Component Description
• The BCM load shed strategy is not active (a message is displayed in the instrument cluster, such as Low Battery Features Temporarily Turned Off or Turn Power Off To Save Battery, to indicate that BCM load shed strategy is active).

414-01 Battery, Mounting and Cables Description and Operation
2025 Maverick - Procedure revision date: 02/5/2025

Battery Load Shed
The main purpose of controlling electrical consumption with a load management strategy is to:
• Limit battery discharge
• Monitor the battery charge status

For vehicles with gas engines the alternator is not dimensioned to support all loads in all situations.
In some situations energy has to be drawn from the battery. These are mainly during:
• engine idle
• cold climate with a lot of electrical heating functions active
• warm conditions with the engine cooling fan running
• large transient loads (i.e. EPAS )

For HEV/BEV vehicles, a DC/DC converter control module is not dimensioned to support all loads in all situations.
In some situations, energy has to be drawn from the battery.

Vehicles built before 2025 have a partial load shed strategy.
Vehicles built after 2025 contain the full load shed strategy.

During cold conditions, the charge acceptance of the battery is very low which increases the time needed to recharge the battery.
This means that it can take up to several hours of driving before the battery is recharged.
The electrical consumption control is using Ignition_Status, Remote_Start_Status and EngineStateInternal in order to define the load management strategy during the different operating states of the vehicle.
The BCM is the primary module that is responsible for controlling the load management strategy.
The BCM processes measurements of the system and uses the information for calculations and load prioritization.
The strategy allows drain to occur from the battery. Load Management minimizes the drain by controlling the time and magnitude of the drain that can occur.
The battery drain changes depending on the driving cycle and the types of loads the driver has activated, therefore, the BCM must be able to shut down or reduce the loads if necessary.
The intent of the initial load shed stage, LSHED1, is to reduce electrical loads in a manner that is not noticed by the vehicle operator.

During LSHED1, requests are sent in a prioritized order for the appropriate modules to begin shedding available loads.
In order to prevent customer satisfaction issues, the loads are requested to reduce power consumption with minimum impact to the customer.

The second load shed event, LSHED2, occurs in two stages, SHED2_TRANS and SHED2_CONTIN.
During operation of a vehicle equipped with large transient loads, there are transient peaks for current draw.

The Load Management algorithm reacts to these spikes by using the SHED2_TRANS state.
This state requires all non-critical loads to shed immediately, without customer indication, so that large transient loads can operate normally with little to no adverse impact to the customer.

SHED2_CONTIN is a continuous deactivation of the loads to ensure the vehicle is able to restart once the ignition is turned off.
During SHED2_CONTIN, a message is displayed to the vehicle operator notifying them of the vehicle's charging system status.

Independent of load shed requests, the Load Management control can request boosts to the engine idle speed.
Boosting the engine idle speed allows for increased output of the alternator to deliver more current to the battery.
Idle speed increases are done through network IBoost messages.

The load shed charts provide a general overview of the features available on the vehicle based on the build options.

Load Shed Charts

2025 Lariat Maverick:

Power Point Relay 3
--> F40 20A -> Rear Power Point RH
--> F35 20A -> Rear Power Point LH

Power Point Relay 2
--> F34 20A -> USB Charge Port
--> F139 20A -> Not Used

Power Point Relay 1
--> F33 20A -> Not Used
--> F32 20A -> Power Point Front

2022 - 2024 Maverick:

Thank you, what an informative post!

I know I will have to re-read it a few more times to try to absorb all the information, but very interesting indeed.

Thanks again,

Andy

 

[BlueSpec1]

414-05 Voltage Converter/Inverter Description and Operation - 2023 - 2024 Maverick

DC/AC INVERTER
The DC/AC inverter converts 12 volts DC to 110 to 230V volts (Depending on market requirement) AC to power AC devices rated 400 watts or less with the vehicle in park, or 300 watts or less with the vehicle in drive.

The 110-120V or 230V volts AC created by the inverter measures differently than conventional, utility generated AC with some multi-meters.
A true RMS voltmeter can be used to measure the appropriate voltage.

400W Inverter Line-Line measurement I made while a heat pad was plugged in.
Wiring diagram doesn't show a ground and outlet doesn't have.

Old reading from a Yamaha EF2400is Inverter Generator by comparison.

 

[MakinDoForNow]

Thank you, what an informative post!

I know I will have to re-read it a few more times to try to absorb all the information, but very interesting indeed.

Thanks again,

Andy

Found this after reading post #74 which has diagram of wiring similar to residential L1+L2=120+120 for 240 circuit one leg being out of phase with the other. =

The 2022 Ford Maverick’s factory 400W system uses a modified sine wave, split-phase inverter topology that outputs two 60V AC legs relative to the chassis ground. However, because the vehicle isolates the electrical system from "true earth" ground, this configuration cannot safely or effectively be wired into a standard residential split-phase (240V) panel. [1, 2]

Understanding the Factory System

• How it works: The 400W system shares 400W of total output across the in-cabin and truck bed outlets. It outputs 2 × 60V AC legs out-of-phase, combining to provide 120V AC. [1, 2]
• Limitations: The factory 400 Watt inverter frequently faults if connected to high-draw appliances, medical devices, or large-motor tools. It is also unsuited for safely back-feeding a home's power grid. [1, 2, 3]

Sponsored