(Another) Parasitic Drain Thread - Hybrid '23 XLT - Battery Disconnect + Maintainer Question

[mhw21zap]

Hello,

I've made several posts and comments about 2023 XLT Hybrid's unfortunate parasitic draw. I've been to two dealerships and I've had my truck in for service 3 different times - NO solution (let alone a diagnosis from any of the service "technicians")

Anyway - I visited my local audio shop and as a courtesy they taught me how to conduct my own amp draw test. My truck is pulling about .250 Amps / 250mA at a constant rate. This explains my constant deep sleep, no cabin lights or screen, and 2 dead batteries that needed to be jump started by my Hulkman 8.5 2000A booster pack (which I can absolutely recommend).

I have both a 1A and 5A Hulkman battery maintainer, which I use when parked in front of my house. However, as I will be taking my wife up through the Sierra Nevadas this weekend, we will be camping several nights and I am naturally a bit concerned. All things considered, a 250milliamp draw isn't usually enough to kill my battery outright, so for each night I should be fine - emphasis on "fine" - this is obviously NOT ideal in any way.

Question:

1) Could I not just disconnect my negative battery terminal from the 12V post (under my seat) at night JUST for extra piece of mind? On any older vehicle or motorcycle this wouldn't be a problem - but - as this is my first hybrid / car with a computer - I wanted to check with the MTC community.

2) Am I correct to assume that if my amperage draw is about .250 of an amp - it would be better to use my 1A Hulkman maintainer for our camping trip and plug it into my portable battery station. I have an EcoFlow River power station that can power my 5A charger for about 4 hours before dying....so, given that I'll be out and about....is it preferable to use my 1A maintainer via my EcoFlow power station? It seems like I would get more juice out of my power station that way to get me through the night

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[GPSMan]

Unplugging the negative terminal is fine, and will probably save you from getting stuck.

You might lose radio presets, and other "learned" behaviors the truck has stored. Stuff like altitude (for the air/fuel mix) may be lost. It may run rough and you may have lower MPG for a while after restarting. But it will start and get you on your way.

You could also start the truck and run it for 15 minutes right before bed, then run it 15 minutes first thing in the morning. I don't think you'd lose too much charge in 8 hours of sleep.

 

[Red Ryder]

I agree, it shouldn't be a problem other than the possible inconvenience of losing presets or relearning fuel trims, which should have little effect on a hybrid's mileage anyhow.

I don't leave home without my Noco jumpstart anymore. Last summer, before I started having the dead 12V issues, I actually left my keys hidden in the vehicle while we rented kayaks at a state park. The keypad entry was a nice, but short-lived convenience. I won't do that now as I often have to open the door manually with a physical key, reach to the back door handle to unlock it, raise the rear seat to extract the Noco. All of this in total darkness, as the failure mode is zero power, including any illumination.

Probably worthwhile for any Maverick hybrid owner to not rely on the wireless keypad (if equipped), to regain entry, especially if in a remote area.

 

[skyhawk]

You need to do a voltage drop test across every fuse and figure out which circuit has the majority of the parasitic load

 

[joemama]

get your vehicle fixed-you dont have to live with this.the proper way to find a draw is to connect an ammeter in series with the battery.after 45 minutes all modules should be sleeping.you start pulling fuses until the draw goes away,and then check that circuit for the cause.

 

[MakinDoForNow]

Hello,

I've made several posts and comments about 2023 XLT Hybrid's unfortunate parasitic draw. I've been to two dealerships and I've had my truck in for service 3 different times - NO solution (let alone a diagnosis from any of the service "technicians")

Anyway - I visited my local audio shop and as a courtesy they taught me how to conduct my own amp draw test. My truck is pulling about .250 Amps / 250mA at a constant rate. This explains my constant deep sleep, no cabin lights or screen, and 2 dead batteries that needed to be jump started by my Hulkman 8.5 2000A booster pack (which I can absolutely recommend).

I have both a 1A and 5A Hulkman battery maintainer, which I use when parked in front of my house. However, as I will be taking my wife up through the Sierra Nevadas this weekend, we will be camping several nights and I am naturally a bit concerned. All things considered, a 250milliamp draw isn't usually enough to kill my battery outright, so for each night I should be fine - emphasis on "fine" - this is obviously NOT ideal in any way.

Question:

1) Could I not just disconnect my negative battery terminal from the 12V post (under my seat) at night JUST for extra piece of mind? On any older vehicle or motorcycle this wouldn't be a problem - but - as this is my first hybrid / car with a computer - I wanted to check with the MTC community.

2) Am I correct to assume that if my amperage draw is about .250 of an amp - it would be better to use my 1A Hulkman maintainer for our camping trip and plug it into my portable battery station. I have an EcoFlow River power station that can power my 5A charger for about 4 hours before dying....so, given that I'll be out and about....is it preferable to use my 1A maintainer via my EcoFlow power station? It seems like I would get more juice out of my power station that way to get me through the night

It would be best to plug either the 1A or 5A maintainer into the DC port of power station to prevent DC/AC/AC/DC conversion loss. However depending on soc of mavericks 12v the power station may need to output 14.6 volts if the maintainer cannot step voltage up on DC input. If all 12v items (AC, lights, radio, etc) are turned off truck could be left in ready state all night. Depending on ambient temp the ice will cycle on every 20-30 minutes if soc of 12v is low. After 12v gets warm bms may adjust voltage to 12v periodically to let it cool or just slower rate of charge. The ice only cycles on when HVB SOC drops to just under 30% so if 12v is getting close to being charged it could be over 2 hours between cycles. The coolant pump for the HVB may periodically come on to heat or cool the HV. Just guessing but don't expect 8-10 hours to burn more than one quart of gas. Amount of gasoline used to bring HB from 30% to 40% has been measured. I think I locked the doors of the maverick with it in ready state (key in truck) using either the lock button on drivers door or possibly the key pad on outside of door.

 

[GPSMan]

The Truck physically measures the temperature of the HV hybid battery. It has actual heating and cooling ability for the HV Traction battery. There is no such control for the 12v battery. It is whatever it is.

Amount of gasoline to charge the HV battery 10% from 30% to 40% has been measured as 0.03 gallons.

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