2021 Ford Raptor and DCDC Charger

[vanhack]

Hi Folks,
I have a Ford F150 2021 raptor which has the 3.5L ecoboost engine, and I have dual battery system from Renogy, using the combined engine/solar charger in 1 unit rated to 50amps, I have the higher unit as I want to charge quickly from the stock alternator which I believe is above 150amps output, perhaps around 200amps, but I cant confirm this.

The issue is the F150 raptor, and many other V6 F150's have a battery manager on the start battery negative post, which reads the volts/amps/temp to regulate the alternator via the ECU, this is needed to allow stop/start function and also save on emissions.

The issue is that the renogy when selected to 30/40/50 from the Bluetooth app, the amps is not stable, fluctuates from 50amps for 1-2 secs and then drops too 0, then climbs up again to 50 for 1-2seconds and swithes off. At 20amps it is stable, for some reason the amps is dropping. I have connected the D+ wire, to compensate for the smart alternator, which essentially means that the charger will switch on when it sees 12.0V, and not 12.8V, but only when the ignition from the truck is hot, when off the charger is off to save the start battery draining into the renogy charger.

I have read on fordf150forum that disconnecting the start battery negative post sensor, will default the alternator to output a constant voltage, but the amps keep fluctuating, we also disconnected the alterantor 3 wire sense wire, no change, and as per ford, moved the auxilliary battery negative to the ground on the truck, which is not ideal, as it should be the start battery negative to give a clean ground, but the logic is that the ECU needs to see the extra load of the charger (50amps) and then compensate for it, if you connect to the negative post of start battery, the ECU will not see the load via the sensor.

 

[vanhack]

Just for the knowledge of others, we found the issue with flickering amps, was due to a faulty circuit breaker on the output of the DCDC charger connected to the battery terminal positive, this was causing the charger to think that there is no battery to charge. Replacing the circuit breaker with a ANL fuse gave us the 50amps continuos.

Also note that we managed to figure out that the FORD BMS system is used in many fords of today, and has been changing in details over the last 10 years, and Australia where the Ford Ranger is popular, has an option for the ranger to be configured on the body control module to have a higher state of charge for the start battery, default seems 80%, and also configure it to dual battery system, not sure if they mean a auxilliary battery system or 2 start batteries such as an F250 super duty, anyhow this raptor is now configured to have 90% state of charge, so charging voltage is pushed up to 14V plus, and dual batter with single sensor.

 

[ConcordCarlos1]

This is interesting to hear. My Victron DC to DC keeps showing an input voltage drop, causing it to cycle on and off. searching the internet it is not an uncommon problem. I need to confirm wire gauge is adequate, terminals are secure and I’ll add breakers to my list of checks after reading your write up.

 

[vanhack]

So to test this, we disconnected the Raptor positive and negative to the charger, and then jumpered the cables with loads of plastic bag insulation to a known working vehicle, in this case a tundra, ran the tundra engine, and just put the raptor in ignition on, no engine running, we noted that the tundra was not able to charge either. We swapped over, this time run the raptor engine to charge the disconnected Tundra dual battery charger, by disconnecting the start battery cables of the tundra, and the raptor was able to charge. Another electrician traced the positive to the charger, and then the output as well. These chargers if they find no battery voltage they do not charge, for obvious reasons.

 

[vanhack]

for wire gauge I use blue sea systems circuit wizard app, always, always take a negative cable from start battery post to the back, and create a negative bus bar, this makes a common ground on the charger and aux batteries, I also up the gauge 1 size to what the app says, but that is because we live in a very very hot climate, and more copper is not that much more expensive, just not easy to route, but my tundra, the test vehicle, has 75mm2 cable for negative/positive, I also draw current for my compressor down this line, if I didn't then 35mm2 would be good enough, or 50mm2 if the cable had to cross the chassis

 

[ConcordCarlos1]

I’ll be digging in and will post results .