P0B24 Voltage Unstable

[Weather Dawg]

Well looks like it’s my turn. Got the wrench, service vehicle soon, and stop now messages. Also degraded power output to 20%. Plugged in my reader and car scanner app to see the P0B24 error. Guess I will be calling the dealer in the morning. 2022 Lariat ER with an August 22 build date. Will keep the thread updated as I find out more.

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[Maxx]

Thanks for sharing and I hope it is not serious. I am curious, what is your module voltage variation (In voltage or percent)

Looking forward to read your status update.

Good luck.

 

[Weather Dawg]

Just added that to the dashboard. 5.4%, min value 3.95 volts, variation of 0.11 volts

 

[Maxx]

Just added that to the dashboard. 5.4%, min value 3.95 volts, variation of 0.11 volts

My module variation usually don’t exceed 0.01 V and 0.5%

 

[ctuan13]

Just added that to the dashboard. 5.4%, min value 3.95 volts, variation of 0.11 volts

Oh no... yeah unfortunately that doesn't look good. That's a lot. Normal variation usually doesn't exceed 0.01 or 0.02V.

Damn. The more instances of this I see, the more I think we're all eventually gonna suffer this fate

 

[The Weatherman]

Oh no... yeah unfortunately that doesn't look good. That's a lot. Normal variation usually doesn't exceed 0.01 or 0.02V.

Damn. The more instances of this I see, the more I think we're all eventually gonna suffer this fate

It is definitely starting to feel that way.

 

[Maxx]

Oh no... yeah unfortunately that doesn't look good. That's a lot. Normal variation usually doesn't exceed 0.01 or 0.02V.

Damn. The more instances of this I see, the more I think we're all eventually gonna suffer this fate

With thousands of batteries in there, it is hard to imagine one of them wouldn’t go out of line.

Not knowing much about the tech, I am not sure how practical this is but it would be nice if there was a way to have a fuse of some sort for each to take it out when it gets out of line. This with 5 or 10 backup cells for the whole pack one of which would come online after a cell failure to keep the total voltage the same, the reduction in warranty calls may offset the additional cost of design or even save Ford some money. Once all of the backup cells are exhausted, the back up module would get replaced along with bad modules/cells. This may have the side effect of the pack lasting longer after warranty as well.

Again someone smarter than me has to figure out how to implement it in a cost effective manner but I hope it is not impossible.

 

[TaxmanHog]

Again someone smarter than me has to figure out how to implement it in a cost effective manner but I hope it is not impossible.

Need thousands of relays to shunt out the bad cell and switch in one of the backup cells, very complicated, not likely worth the complexity & costs

 

[Maxx]

Need thousands of relays to shunt out the bad cell and switch in one of the backup cells, very complicated, not likely worth the complexity & costs

You are probably right. It depends on what the cost of warranty repairs are for Ford. or how quickly a new more reliable battery chemistry/tech becomes available.

However doing things at cell level may not be always as expensive as you think. Tesla has a fuse for every cell (just a thin wire). And looking at the attached info, although Ford is not watching every cell, they are watching every five sells. In fact, that means the backup batteries are already baked in. If every 5 cells are in parallel, taking out the bad cell by blowing out a fuse will stabilize the voltage for that group without the need to do anything to the pack. The only thing is the total energy is reduced by 0.2 % which is hard to notice. You can do this three more times for the same group without needing to open up the pack. Which means you may never have to fix the pack for the life of the vehicle due to cell problems.

Just shooting off potentially more stupid ideas: If a bad cell has higher voltage than others, could we blow out it's fuse with a hard acceleration? Meaning push slightly more current through a sensitive fuse (like what Tesla has but with smaller tolerance) beyond its limit and take that cell out of business? Not sure how much of a problem low voltage is and how to take those out.

I know how all of this sounds from someone that does not know what he is talking about, but I have faith that someone that is in the right field (may be biology) can come up with a smart way to blow out the fuse like nature does with most of it's operations; Smart but without a microchip.

 

[Weather Dawg]

Spoke to the service manager yesterday and I am going in on Monday for them to test and determine next steps.

 

[TaxmanHog]

Ok, knocking out a parallel branch with a fuse might be something, but swapping in a replacement group of cells is where the relays and complexity would come into play and in my vision would be to complicated and costly

 

[Piquette]

If I remember what my service technician told me correctly, if a single cell’s voltage falls 0.03 volts or more below the nominal output of 4.03 volts, the truck goes into reduced power mode. On my truck, the voltage in cell #96 in Module #9 dropped to 3.97 volts. Not much of a drop, but still enough that Module #9 had to be replaced with a new one.

 

[Maxx]

If I remember what my service technician told me correctly, if a single cell’s voltage falls 0.03 volts or more below the nominal output of 4.03 volts, the truck goes into reduced power mode. On my truck, the voltage in cell #96 in Module #9 dropped to 3.97 volts. Not much of a drop, but still enough that Module #9 had to be replaced with a new one.

That sounds tight. It feels like it is something that is waiting for a lot of us.

 

[Ford Motor Company]

Well looks like it’s my turn. Got the wrench, service vehicle soon, and stop now messages. Also degraded power output to 20%. Plugged in my reader and car scanner app to see the P0B24 error. Guess I will be calling the dealer in the morning. 2022 Lariat ER with an August 22 build date. Will keep the thread updated as I find out more.

Hey there. Can you send over a message with your VIN and the name/location of your local Ford dealer? I would like to look into this error issue on my end.

 

[Weather Dawg]

Hey there. Can you send over a message with your VIN and the name/location of your local Ford dealer? I would like to look into this error issue on my end.

Thanks. Just sent the message.

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