12V battery replacement

[SpaceEVDriver]

The voltages are close enough to not make a difference. The main difference being charge/discharge curves et al.

The top-end and bottom-end voltages are similar. But the voltage of a Lithium battery at 25% looks the same as the voltage of a Pb-A battery at 90%. So when the lithium battery is at 25% and is still providing a voltage similar to a 90% SoC AGM, the truck won’t think it needs to charge the battery.

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[chl]

Already!? OK, have to check it out.

I have time to wait for the price - $379 - to come down - 3 year B-B warranty ends Jan 2027, may need a replacement AGM by then when it fails, sodium (or whatever the best replacement is at the time).

https://www.ohmmu.com/product-page/12v-sodium-battery-for-ford

 

[Maxx]

Already!? OK, have to check it out.

Yes there was an update recently that changed the program for maintaining the 12V - but does it use the DC-DC converter to top off the AGM? All lead acid batteries prefer 100% charge for longer life...

As far as DC to DC goes, it must be. All power sources in the truck are DC (HVB and LVB). I didn't get to check to see what the threshold at which the charging kicks in now after the update. I immediately turned on the truck as soon as I saw 50% SOC and got it up to 73% and on my next drive to 84%.

My latest update has also made the truck turn on lane keep assist everytime I turn on the cruise control. It is annoying the heck out of me. Not sure if I can change the behavior in a setting somewhere or I am stuck with it.

 

[El Duderino]

The top-end and bottom-end voltages are similar. But the voltage of a Lithium battery at 25% looks the same as the voltage of a Pb-A battery at 90%. So when the lithium battery is at 25% and is still providing a voltage similar to a 90% SoC AGM, the truck won’t think it needs to charge the battery.

Pretty flat discharge curve. I see your point now.

 

[SpaceEVDriver]

Pretty flat discharge curve. I see your point now.

Glad the point made it somewhere.

A Li battery on an AGM BMS could easily be left in the 0% to 25% range. It is also likely never to reach full charge because a 100% SOC Li battery has a higher voltage than a 100% SOC AGM battery.

And because of the steep drop at the bottom end of the Li battery’s SOC curve, there could be very little warning that the Li battery is about to be dead. So a Li battery on a Pb-A BMS might only have ~25% of its Ah rating available for regular use. You might need a 70-140 Ah Li battery to get the same Ah of use as you would in the H3 in the Lightning.

Coulomb counting works much better for Li than for Pb-A and voltage measurements work much better for Pb-A than for Li (see your chart and the one I posted earlier). So the BMS charging strategy for the two batteries is likely different.

Again, this is assuming one just puts a random Li battery in place of the H3 AGM that came from the factory. If there’s a translation layer between the Li battery and the truck’s LVB BMS, that may mitigate this concern.

 

[Zprime29]

My latest update has also made the truck turn on lane keep assist everytime I turn on the cruise control. It is annoying the heck out of me. Not sure if I can change the behavior in a setting somewhere or I am stuck with it.

Several threads about this, one of the most annoying changes @Ford Motor Company made. Should have left them as independent toggles. I tried turning it off, but then I can't get Blue Cruise to activate.

 

[Lytning]

I bought and installed in my Lightning an Ohmmu Li-H3-BH (LFP) 12 Volt Battery two weeks ago, based upon positive user comments on this forum. I just returned from a 25 mile errand trip. Ohmmu 12 volt SOC, easily accessible in the Ohmmu app, is at 100%.

Among several reasons for rewarding Ohmmu with my purchase, them delivering an easily accessible 12 volt battery SOC was near the top of my list ... something that @Ford Motor Company would not do in over 3 years.

Now, if Ohmmu sold BlueCruise 1.4 ...

Attached are screen copies of 12 volt data from the Ohmmu app and Car Scanner at the same time in my Lightning. Both show 100% 12 volt SOC. Ohmmu shows 14.39 volts, and Car Scanner shows 14.2 volts at the battery and 14.4 volts at the OBD port. Interestingly, both show 0 amps 12 volt battery current. Car Scanner shows 49 amps DC-DC Low Voltage. The truck was "On" with the AC running when the data screens were captured. It appears that the main battery DC-DC Low Voltage powers all 12 volt users when the truck is running, and the 12 volt battery is inactive.

 

[Maxx]

Attached are screen copies of 12 volt data from the Ohmmu app and Car Scanner at the same time in my Lightning. Both show 100% 12 volt SOC. Ohmmu shows 14.39 volts, and Car Scanner shows 14.2 volts at the battery and 14.4 volts at the OBD port. Interestingly, both show 0 amps 12 volt battery current. Car Scanner shows 49 amps DC-DC Low Voltage. The truck was "On" with the AC running when the data screens were captured. It appears that the main battery DC-DC Low Voltage powers all 12 volt users when the truck is running, and the 12 volt battery is inactive.

It looks like Truck provides the same voltage to my battery (OEM) and Yours. I get 14.35V when truck is running and 12.4V when it is off at 100% LVB SOC. It is the first time I see mine at 100%. I drove for 140 miles yesterday and charged for eight hours last night. That should do it. What I don’t know understand is that this morning around noon, when I tried to leave fan started going crazy trying to cool something. My AC was not running. Granted truck was sitting in the sun for a few hours but when I checked the battery temp, it was at 73F with ambient temp at 82.

Note; by the time I plugged in to ODB II, the fan had already stopped cooling. It was running 1-2 minutes. I doubt battery temp can drop from really hot to 73 that quickly. Does anyone know what was fan cooling?

 

[htobin]

This evening when I turned off my truck, I got the following message. Not sure what it means. I have been parked for about an hour with the car running and I’m not sure if that had anything to do with it my truck is a 2023 lariat with about 25,000 miles. Is that any indication that I might need a 12 V battery exchange? I did turn it off and on and got the same message. Everything else seems fine

 

[TaxmanHog]

Is that any indication that I might need a 12 V battery exchange? I did turn it off and on and got the same message. Everything else seems fine

Possibly, you could take it in for a battery test.

 

[Maquis]

This evening when I turned off my truck, I got the following message. Not sure what it means. I have been parked for about an hour with the car running and I’m not sure if that had anything to do with it my truck is a 2023 lariat with about 25,000 miles. Is that any indication that I might need a 12 V battery exchange? I did turn it off and on and got the same message. Everything else seems fine

Are you sure you had the truck “running?” It looks like it was in accessory mode. That’s why it’s telling you either turn it on or turn it off.

 

[htobin]

It occurred when I shut down the truck. I restarted it and shut it down again and got the same message

 

[Basis0439]

Is there a consensus, off-the-shelf, 12v battery replacement suggestion?

 

[jeff_h]

Is there a consensus, off-the-shelf, 12v battery replacement suggestion?

This is the internet so there's never a consensus on anything... but when I replace mine I'm going to get this one:

https://shop.advanceautoparts.com/p...-ca-60-min-reserve-capacity-h3-xev/50001096-P

 

[GunRack]

I was getting the weird sound issue and my interior lights weren't coming on when I opened the doors. My truck only gets short runs around town and sits for a week or two at a time between. So I figured better to just get the lithium battery for the increased capacity.

Just installed a Li-H3-BH today. While taking it out I noticed the OEM was 35Ah, but I couldn't find the capacity of the Ohmmu on their website. It says longer lasting, but what is the Li-H3-BH capacity?

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