12V battery replacement poll

[21st Century Truck]

I proactively replaced my (second) OEM 12 volt battery at the 3 year mark with an Ohmmu Li-H3-BH (LFP) battery. It is definitely expensive, but I am very happy with results. It stays in the 90% to 100% SOC range, and SOC is viewable within Bluetooth range on a mobile phone.

I am not associated with Ohmmu in any way. They are offering a 20% Black Friday discount at the current time.

https://www.ohmmu.com/?utm_campaign...mail&cid=2cedc2fc-640b-47df-a436-dcc68464e997

Thanks for this.

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[DarkL1ghtn1ng]

I have a '23 bought in January of that year. I am on at least battery #3. All replaced under warranty.

 

[Lytning]

On an associated 12 volt battery topic ... I am curious what others have seen regarding the charging current to their 12 volt battery. Using the Car Scanner app on CarPlay, I recorded 43 amps. On another short trip, which I did not record, I seem to remember 72 amps. Has anyone else recorded or observed their charging 12 volt charging amps?

I obtained another data point today via the Ohmmu app. Although SOC is shown at 100%, I have noticed several times of charging for a few minutes to top off the battery. The attached screen copy shows 55.01 amps to the Ohmmu 12 volt battery. This number slowly reduced down to about 1.25 amps after 2 to 3 minutes. After returning home from a 25 mile trip with 2 stops, the app showed 12 volt SOC at 100% with 0 amps in/out.

 

[NW Ontario Ford Lightning]

That's the beauty of the lfp battery

But the down side is cold. LFP can't be charged below freezing and has limited discharge below freezing.

 

[htobin]

Wow! All this sounds so complicated. With a gas engine you replaced the battery when you needed a jump start. Apparently that strategy doesn’t work so well for an electric car

 

[mr.Magoo]

Wow! All this sounds so complicated. With a gas engine you replaced the battery when you needed a jump start. Apparently that strategy doesn’t work so well for an electric car

It's only as complicated as you make it, the principle for replacement haven't really changed.

 

[bmwhitetx]

Wow! All this sounds so complicated. With a gas engine you replaced the battery when you needed a jump start. Apparently that strategy doesn’t work so well for an electric car

Some people are making this appear complicated. It’s not. If you get notices that your 12V is having issues, have the battery checked and replaced if needed. Or just replace every x years.

Just in case, learn how to open the frunk with a dead battery so you can jump start it just like a gas vehicle.

 

[bthanos]

I proactively replaced my (second) OEM 12 volt battery at the 3 year mark with an Ohmmu Li-H3-BH (LFP) battery. It is definitely expensive, but I am very happy with results. It stays in the 90% to 100% SOC range, and SOC is viewable within Bluetooth range on a mobile phone.

I am not associated with Ohmmu in any way. They are offering a 20% Black Friday discount at the current time.

https://www.ohmmu.com/?utm_campaign...mail&cid=2cedc2fc-640b-47df-a436-dcc68464e997

I got the Ohmmu Battery as well. No issues at all so far. Hope it lasts a long time

 

[mr.Magoo]

I got the Ohmmu Battery as well. No issues at all so far. Hope it lasts a long time

For every "Ohmmu is amazing" post there should be a mandatory warning post with this:


or - at a bare minimum a disclaimer mentioning that they're not suitable for vehicles being used in cooler climates (that see below freezing temperatures).


Ohmmu might be great for some, but it is definitely not a solution for everyone.

 

[bthanos]

Old post, I have the new one with Bluetooth and self heating.

 

[Lytning]

For every "Ohmmu is amazing" post there should be a mandatory warning post with this:


or - at a bare minimum a disclaimer mentioning that they're not suitable for vehicles being used in cooler climates (that see below freezing temperatures).


Ohmmu might be great for some, but it is definitely not a solution for everyone.

I expect mine is built like the one in the video at this link ...

 

[chl]

Wow! All this sounds so complicated. With a gas engine you replaced the battery when you needed a jump start. Apparently that strategy doesn’t work so well for an electric car

Since around 2011 Ford started putting a 12V battery management system in their F-150s and I assume other vehicles, because so much is now 12V battery powered and it is even more important that it used to be, according to reliable information from the Internet (is that an oxymoron? yes sometimes).

And it seems that even the ICE F-150s will have their batteries go low if not driven maybe 45 min to 1 hour every day.

The problem is the load on the 12V system doesn't leave 'room' for significant battery charging if you only drive short trips all the time whether it is recharged by an alternator in an ICE truck or the DC-DC converter in our Lightnings. Of course when off there are also small parasitic loads that add up over time.

Then funny things start to happen.

First you may get a warning message on the screen that loads are being shed to maintain the battery when you first turn off the truck. You may notice the lights don't stay on very long when you first unlock the truck as well. Before I put my Lightning 12V battery on a trickle charger I would see that happen. In ICE F-150 trucks the message may say "System off to save battery" and then the truck will go into a battery saving mode.

Later the truck may not boot up (or start if ICE) without a jump.

In Lightnings another symptom is failed OTAs - some OTAs require at least an 80-85% or so 12V battery SOC so they can fully install. I saw that happen as well.

I just learned recently that some people are reporting high 12V battery charging currents - if true, that is a sign of a deeply discharged battery (50% or lower), and it is not a good thing.

That would also indicate that the battery management system for the Lightning (maybe ICE F-150s also) does not control the charge current so that it stays at or below an optimum level when the battery is deeply discharged. High currents are not good for AGM batteries and will shorten their lifespan. Neither is a deep discharge level.

So, if you are like me, and don't drive 45 min to 1 hour every day, putting the 12V battery on a trickle charger with an AGM mode seems like the best way avoid those issues and make the 12V AGM battery last.

Keeping the battery topped off is always a good idea with any lead-acid battery anyway.

There are other ways to cause the DC-DC converter to charge the 12V battery without a trickle charger and get your OTAs to install (see link):

https://www.macheforum.com/site/threads/how-to-get-failed-otas-to-install.29749/

So to simplify it all: Keep the battery topped off - if you don't drive at least 45 minutes every day, get a trickle charger with an AGM mode and connect it when the truck is not being used.

 

[bthanos]

All these problems solved with Ohmmu Lion Battery.

 

[Ford Motor Company]

Hello, Brian, not AI, @Ford Motor Company,

Can you find out and inform us what the maximum charge rate is to the 12 volt battery in our Lightnings?

Thank you,

Steve

I'll ask!

 

[Ford Motor Company]

@chl The BMS (sensor) monitors the current through it and reports that along with temperature and battery age to the BCM via the LIN bus. The BCM then provides the PCM with a SOC and the PCM decides a voltage setpoint for the DC-DC converter (e.g., I've seen 13.7V and 14.4V) which affects how fast or slow the battery will charge (accept current). The SOBDMC also gets involved.

There is not a specific charging current. If Brian says a single number, he's wrong. The current varies and dependent on the voltage the DC-DC has been instructed to provide and other 12V loads. It doesn't provide a constant current. But the BMS tells the system the current flowing in and out of it - and by the PCM adjusting voltage then current can be somewhat regulated in and out of the battery. I see you're also an EE - think KVL, KCL, Ohm's law.

I have taken a BMS apart - it has a microprocessor so its doing some calculations. There is definitely no switch, valve, contactor, etc. It has a current sensor (Hall Effect?) built into the plastic between the input and output lugs.

You might want to spend $29 on a 3-day subscription to PTS. The Service manual has wiring diagrams, system operation description, etc. Much better source than any AI.

PICS: LIN bus and battery positive enter from two pins on upper right. My best guess is current sensor and battery negative are present on the three large pins on the left.

Is there where I say "there isn't a single number"?

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