12 volt battery monitor

[potato]

There is a LOT of wishful thinking in this thread. Ford does not even want us to know that a 12 volt battery exists. They do mention it in the manual but only because they have to in the case of roadside failure, I think. My 23 doesn't even have charging rate on the dash. It was a battle just to get the main battery state of charge % displayed. Expecting a battery voltage / SOC display for an auxiliary battery is a pipe dream even if they were still developing this truck. They have a laser focus on dumbing down the interface so we will just take it to the dealer for anything.

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[mr.Magoo]

I expected the new BMS would have had a higher trigger point than 40% SOC.

just so that we're all on the same page, the 40% threshold is for when the truck is OFF.

And no that limit did not change (that I've seen) and it would also be a software setting unrelated to new/old sensor.

 

[Maquis]

just so that we're all on the same page, the 40% threshold is for when the truck is OFF.

And no that limit did not change (that I've seen) and it would also be a software setting unrelated to new/old sensor.

I seem to recall that it was changed to 50%. AGM batteries can be damaged if they are charged when the temp is below freezing and the SoC is below 50%.

Here is a great writeup on the 12V battery. Applies to both the Mach-E and Lightning.
https://www.macheforum.com/site/threads/12v-battery-faq.32744/

 

[TechnoSwiss]

Also using a similar device to @RLXXI, a BM2 device like several others are. I don't care for their app much, so I've got a Raspberry Pi setup to read the device and log the data to my own server.

 

[Adventureboy]

I’ve seen these online but not sure if they work or not. https://amzn.to/49gYjIB

They are not much use since they only give you a reading when the truck is ON or ACC mode. The real value is understanding what is happening when the truck is OFF.

 

[potato]

Also using a similar device to @RLXXI, a BM2 device like several others are. I don't care for their app much, so I've got a Raspberry Pi setup to read the device and log the data to my own server.

Getting a bit off topic I suppose, but can you recommend any resources for setting up a Pi for remote monitoring?

 

[TechnoSwiss]

Getting a bit off topic I suppose, but can you recommend any resources for setting up a Pi for remote monitoring?

For the BM2 battery monitor https://github.com/TechnoSwiss/bm2-battery-monitor which is my branch of KrystianD's implementation, I have a few fixes in mine for timestamps on the history data that I don't know if they've been merged yet to their branch. Since the BM2 use BLE no other hardware is needed for receiving (although I found it works better with a USB BLE adapter with an external antenna, I use https://www.amazon.com/dp/B09KG7QQ5V). What you do with that data is a pretty long topic. I use the python code, but the repo has esphome code that I think you can use to import data directly into home assistant. In my case I'm sending out MQTT reports, and then using telegraf with influxdb to collect those reports, and then grafana to graph it. For more general collection of sensor data with a Pi https://github.com/merbanan/rtl_433 is a great resource for using an USB SDR and pulling in all kind of sensor data from consumer devices (I use that project to, for example, monitor the TPMS sensors in my Lightning, and collect temperature data from my EVSE) If you'd like more detailed information, happy to move that discussion to another thread or other more appropriate area.

 

[mr.Magoo]

Getting a bit off topic I suppose, but can you recommend any resources for setting up a Pi for remote monitoring?

If the only thing you care about is the 12V battery I'd recommend using a esp32 instead, something like M5Stack for example. I'm guessing that TechnoSwiss setup is using 3-5W at least which will drain the battery in 3-4 days if left running (which may or may not be a problem for you).

If you do go with a Pi, you might as well go full OBD logging if you like data, check out the post about my black box.

 

[potato]

Thanks guys. That is enough info to be dangerous I think

For just the 12V monitoring I think I'd be fine with the app from the BM200. I'll start with that. What I was thinking longer term was for monitoring the interior temperature. Even though I've had no problems to date, leaving the dog in the car with the climate running is life and death. So I was thinking about setting up redundant monitoring of some sort, using a cellular modem Pi hat I guess, to send a notification if the temperature starts to deviate. But as you say that's a pretty deep topic lol. Lots of moving parts.

 

[TechnoSwiss]

If the only thing you care about is the 12V battery I'd recommend using a esp32 instead, something like M5Stack for example. I'm guessing that TechnoSwiss setup is using 3-5W at least which will drain the battery in 3-4 days if left running (which may or may not be a problem for you).

If you do go with a Pi, you might as well go full OBD logging if you like data, check out the post about my black box.

The Pi lives in the garage and pulls live data when the truck is parked at home, and downloads the historical data for when it's not. Yes, if you plan on having it live in the truck an esp32 would be the way to go.

 

[davehu]

Why can’t Ford provide an update so we, the consumer, are able to visually monitor the 12 volt battery.
........

At one time you could see the 12v charge from the vehicle by logging into ford.com and looking at the dashboard. Caused a lot of confusion and they eventually changed it to show only the HVB charge. here's my post when I discovered it a back in summer 2024 FordPass and web dashboard with different info

 

[brewski]

So...when should we change our 12v battery? Unlike an ICE vehicle (during start) there is not "obvious" indication of its pending failure...that I'm aware of.

 

[chriserx]

Thanks guys. That is enough info to be dangerous I think

For just the 12V monitoring I think I'd be fine with the app from the BM200. I'll start with that. What I was thinking longer term was for monitoring the interior temperature. Even though I've had no problems to date, leaving the dog in the car with the climate running is life and death. So I was thinking about setting up redundant monitoring of some sort, using a cellular modem Pi hat I guess, to send a notification if the temperature starts to deviate. But as you say that's a pretty deep topic lol. Lots of moving parts.

If you have wifi in the truck, all of this is certainly feasible, I'm not certain the the modem in the truck will allow incoming connections so you'll like have to setup a server of some type, if you really are serious about it and are at least modestly proficient (I assume this is true since you knew what a pi was) shoot me a DM and I'll help out with what I can.

 

[Adventureboy]

I'm guessing that TechnoSwiss setup is using 3-5W at least which will drain the battery in 3-4 days if left running

Agree, this might be troublesome. Since it is Bluetooth, it could be set up close to the normal parking spot plugged into the garage, and it can download when parked in range. This way, it wouldn't need to be attached to the tiny truck battery.

 

[Tired Lizard]

For my 2 Fords(Escape PHEV 3yr old, Maverick Hybrid 2yr old) AGM batteries I've been hooking up a Battery Tender 15 Amp Charger and Maintainer set to Auto twice a month.

My Bolt EUV somehow does a better job maintaining the 12V battery in it.

I've usually had to replace my previous car batteries when they're a bit over 3yrs old.
Mostly from high summer heat I guess.

Maverick LN1AGM 12V battery charge a couple days ago:
(minus several minutes at start of charging as I setup my Clamp On.)

BM2 Trend Chart:

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