Another 12v battery bites the dust

[Zzzz...]

I'm suggesting they may already be certified for that voltage.

They are not. Certification for li-ion voltage curve is totally different beast.

Upfront costs, no, but actual lifetime costs, I think at least LiFePO4 is already cheaper than a good AGM battery.

Current NCA li-ion pack designed to last lifetime of the car, Tesla Model S. If LFP could last 100 or 1000 times longer than the Model S itself - that would not change a thing for an automotive application of it. So upfront cost is what matters. Comparing it to AGM makes no sense at all - AGM are not used in Tesla Model S or Model X and most likely(read 0 chance) would not be used in Model 3.
If in your imagination AMG batteries will be used in automotive world - we got a principal disagreement.

Since they would see traction loads as well as 12V loads they would have to cycle more frequently and under greater load than the rest of the pack.

Sure I meant cells that are separated from traction loads. I could not imagine how one cell could participate at both loads simultaneously. And this is why I wrote QUOTE: "separate and totally independent part of main pack" <--- but with your selective reading skill I see how in your mind cells in separate and independent parts of main pack could see both traction loads as well as 12V loads....
In reality I meant only possible savings from assembly of battery pack - same cells that designed to last for the life of the car will make sense to place into same case.

 

[JRP3]

They are not. Certification for li-ion voltage curve is totally different beast.

The "curve" is irrelevant, components only need to be certified for the maximum voltage they will see.

Current NCA li-ion pack designed to last lifetime of the car, Tesla Model S. If LFP could last 100 or 1000 times longer than the Model S itself - that would not change a thing for an automotive application of it. So upfront cost is what matters. Comparing it to AGM makes no sense at all - AGM are not used in Tesla Model S or Model X and most likely(read 0 chance) would not be used in Model 3.
If in your imagination AMG batteries will be used in automotive world - we got a principal disagreement.

Not sure what you're on about since Tesla uses an AGM battery for their 12V battery, which is what we've been talking about this entire thread.

Sure I meant cells that are separated from traction loads. I could not imagine how one cell could participate at both loads simultaneously. And this is why I wrote QUOTE: "separate and totally independent part of main pack" <--- but with your selective reading skill I see how in your mind cells in separate and independent parts of main pack could see both traction loads as well as 12V loads....
In reality I meant only possible savings from assembly of battery pack - same cells that designed to last for the life of the car will make sense to place into same case.

"My mind" was directly addressing another comment regarding using part of the main traction pack for 12V loads, which you addressed as well, though maybe didn't actually understand the question. It is theoretically possible but not a good idea for the reasons I outlined. You probably should not be attacking my reading skills and just stick to the topic at hand.

 

[tliving]

I think that the 12V warning comes on for different reasons. Some may just be a dropping voltage level on the 12V indicating its near end of life. If thats the case you can keep driving for a while until you can get it into a SC. I think another cause may be when the DC-DC inverter fails and the 12V is getting no charge. In that case its going to die quickly and potentially leave you stranded. The best bet is to call Tesla Service (24x7) and get their advice. I don't think they're giving inconsistent advice, I think it depends on what actually caused the warning.