Charging system issue with ham radio.

[wb5oxq]

I have discovered a problem with the charging circuit. When there is no electrical load such as headlights, A/C etc the charging circuit is mostly off. Battery voltage shows 12.5 volts. turn on the headlights and it goes to 13.8, same with A/C. with every accessory turned off I get under 12 volts to the radio and amplifier when transmitting. Turn headlights on and I get 13.5. How can I get the truck to detect the load on the radio power cable?

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[Aherpa]

I have discovered a problem with the charging circuit. When there is no electrical load such as headlights, A/C etc the charging circuit is mostly off. Battery voltage shows 12.5 volts. turn on the headlights and it goes to 13.8, same with A/C. with every accessory turned off I get under 12 volts to the radio and amplifier when transmitting. Turn headlights on and I get 13.5. How can I get the truck to detect the load on the radio power cable?

Where is the radio currently tapped into power? Is it directly from the battery?

 

[fossil]

I have discovered a problem with the charging circuit. When there is no electrical load such as headlights, A/C etc the charging circuit is mostly off. Battery voltage shows 12.5 volts. turn on the headlights and it goes to 13.8, same with A/C. with every accessory turned off I get under 12 volts to the radio and amplifier when transmitting. Turn headlights on and I get 13.5. How can I get the truck to detect the load on the radio power cable?

Like @Aherpa I need more info. Are you measuring <12v at the radio or where the radio connects to the 12v supply?
To more exactly trouble shoot the issue I would measure at the radio, the 12v connection and the actual battery if different when transmitting.

 

[wb5oxq]

Like @Aherpa I need more info. Are you measuring <12v at the radio or where the radio connects to the 12v supply?
To more exactly trouble shoot the issue I would measure at the radio, the 12v connection and the actual battery if different when transmitting.

Checked both ways. At the battery, engine running headlights off battery measures 12.5. Turn the headlights on and it will rise to 13.8 at the battery. Immediately after starting the engine it is 14 volts at the battery for a few minutes only. These have AGM batteries that cannot be charged as high as regular liquid acid batteries.

 

[fossil]

Checked both ways. At the battery, engine running headlights off battery measures 12.5. Turn the headlights on and it will rise to 13.8 at the battery. Immediately after starting the engine it is 14 volts at the battery for a few minutes only. These have AGM batteries that cannot be charged as high as regular liquid acid batteries.

so you can transmit at full power with the headlights on? you still have not stated where you are getting the 12v, where did you tap in. not jerking you around, it's a 5min diagnosis in person but already days over the thread.
BTW, fully aware of AGM differences/shortcomings, not a fan.

 

[wb5oxq]

so you can transmit at full power with the headlights on? you still have not stated where you are getting the 12v, where did you tap in. not jerking you around, it's a 5min diagnosis in person but already days over the thread.
BTW, fully aware of AGM differences/shortcomings, not a fan.

The + 4 gauge cable is bolted to the battery terminal, the - cable is connected to the chassis location under the hood where the- battery terminal is connected.

 

[fossil]

The + 4 gage cable is bolted to the battery terminal, the - cable is connected to the chassis location under the hood where the- battery terminal is connected.

That's about as right as it could be.
What kind of wattage are you transmitting and again does it work correctly with the headlights on?

 

[BradnChristine]

That's about as right as it could be.
What kind of wattage are you transmitting and again does it work correctly with the headlights on?

I thought there was a Battery Management System in the Maverick that really required power connections to be made under the hood when adding accessories that USED TO BE better connected to the battery terminals. I may have been mistaken, but I thought I saw warnings from other applications not to directly connect to the battery, as the BMS can't see the load. Life used to be simpler ~WA7QOK

 

[wb5oxq]

I thought there was a Battery Management System in the Maverick that really required power connections to be made under the hood when adding accessories that USED TO BE better connected to the battery terminals. I may have been mistaken, but I thought I saw warnings from other applications not to directly connect to the battery, as the BMS can't see the load. Life used to be simpler ~WA7QOK

The BMS module is on the - battery terminal. That is why I did not connect the - cable to the battery. I connected it to the frame rail under the hood on the drivers side. If there is a Ford tech listening tell me where to connect the + cable that can supply up to 50 amps but a short duty cycle on SSB.

 

[GPSMan]

This is very interesting.
I thought this was a quirk of the Hybrid not having an engine mounted alternator.

Hybrids have to step down 220v to charge the 12v battery. And it seems unpredictable.

Well, 12.5v or less, we can tell the DC/DC converter is "off".

But there is "low" mode.
Accessory mode I get 13.5 volts.

There is "high" mode.
With key to run, I get 15 volts.
It does not matter if the engine is actually turning or not.

Also even though it is 15v it is not giving the 12v battery any current. Or just milliamps.

With key to run the 220v battery powers everything, just steps it down.
I could probably remove the 12v battery and things would run fine.
(But I guess you could do that in any car once the alternator is spinning.)

 

[wb5oxq]

That's about as right as it could be.
What kind of wattage are you transmitting and again does it work correctly with the headlights on?

250 watts on SSB the only mode I use mobile. With the headlights off the analog wattmeter shows about 230 watts to the antenna. With the headlights on it shows about 255 watts to the antenna. Probably not a difference anyone could hear anyway. I also have a body ground with 4 gauge cable to a ground point behind the rear seat to help lower voltage drop on the front negative cable. I seem to get out very good on 20, 15, and 10. Fairly good on 40 and surprisingly good on 75. My antenna is a Tarheel 75A with a 30" rod and a loop type capacity hat. That uses less coil turns than the supplied 6" whip and lets me get in to most drive through sites with no problem since I am under 8'5' om 75 and even less on 20 and up. The radio is a FT891.

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