Vendor Antigravity Group 51R LiFePO4 Lithium battery for Tesla Model 3/Model Y

[android04]

@android04 - I didn't mention Lead Acid at all.

My point is that if 11 lbs gave you 44Ah (perfectly reasonable for LFP), than 14Ah wouldn't weigh 9 lbs. It would weigh about 3lbs. There's no way the V2 was only 14Ah, and if it was, it was hugely overpriced and had a lead weight inside. That was my only point that your 14Ah estimate was not accurate.


You're driving yourself in a logic circle. Lead acid was 44Ah, so V1 was 44Ah, but you really can't use that, only 10-20Ah, so V2 was 14Ah, but now V3 is 44Ah again, because that will fix the errors this time. Plus, just because you should only use 20% of a LA's capacity doesn't mean it doesn't have 100%, and when you measure that battery, you will measure it at 100% capacity. If the charge algorithm was expecting a 40Ah battery but then was only going to use 10Ah of it, it would still expect to see 40Ah, and you can't just hand it a 15Ah capacity battery of different chemistry and expect it to be happy. It should rightly freak out when it thinks your 40Ah battery has degraded to 15Ah. This is not just a dumb float charger.

Tesla is not detecting LFP via capacity measurements. You can see this because they will throw an error long before they would be able to estimate battery capacity, and over the fact that they throw errors even when a very equivalent capacity battery is present. They're using other characteristics of LFP, such as higher float voltage to detect the different chemistry and this is what all LFP 12V vendors are going to have to figure out how to work around.

Tesla isn't "detecting" LiFePO4 batteries at all -- they just happen to not behave exactly like Tesla expects their OEM lead acid battery to behave. That anomaly is what flags a "battery issue".

And no, Tesla will not be able to measure the full capacity of the lead acid because to do so would drain it and kill it really fast. Tesla does measure how much charge goes into and out of the battery through a shunt and uses that info to determine if there are any issues. Of course, they try to account for any charging losses, etc. This is the reason why you might hear people say not to tap directly into the 12v battery for things that might drain too much power, because that drain doesn't go through the car's shunt and the drain isn't measured or accounted for. Which could cause the car to think your lead acid battery is failing.

My point about Ohmmu possibly reducing the battery capacity in gen 2 is that it was because the car doesn't actually cycle the full capacity of the larger battery, and it's therefore a waste. Or that the larger actual capacity can cause issues if the battery happens to be, or gets, low enough to need a charge much greater than the lead acid would take. In this scenario, the car it's keeping track of how much charge is going into the 12v battery and it's greater that it would be for a lead acid might determine that there's a shorted or dry cell in the 12v battery.

Now to get back on subject, I've come across the Antigravity batteries before when researching possible replacements for my Model 3's lead acid battery. A few things ruled out out for me:
1. The closest fit battery available then was the ATX30-HD model, which required battery terminal adapters (not a big deal for me, since they can be had for about $15).
2. At $560 it was more expensive than even the other LiFePO4 batteries I was looking into (Ohmmu, EarthX, ReliOn).
3. The info on battery didn't specify if there was a low temperature cutoff.

That said, it's nice that they now have a group size 51R battery that we can use on our Model 3s or Ys if we want to. Hope to hear feedback from users. My original lead acid is still working fine in my Model 3 after more than 4 years and 78,000 miles, so I haven't had to replace it yet. And I won't replace it until it fails because I'm prepared to handle it. I can easily pop open my frunk and jump start myself.

 

[voltaholic]

SInce these are made in china, I'm wondering why the chinese didnt test them out 1st ???
2nd, at $500+, why is this news ?

 

[CMPT PAD]

From what I understand, Tesla Y and 3 models delivered after March 2022 would have AMD chip and new Lithium Ion chip, same as that of in X and S models (not LiFePO4)

 

[drew.cleaver]

Thanks for sharing. I was hoping for a bit more weight savings but the features are pretty nice. OEM isn't heavy enough to allow as much improvement as hoped I suppose.

I'll consider one after I take the -20lb freemod sitting in the driver seat.

 

[tom @ eas]

Thanks for sharing. I was hoping for a bit more weight savings but the features are pretty nice. OEM isn't heavy enough to allow as much improvement as hoped I suppose.

I'll consider one after I take the -20lb freemod sitting in the driver seat.

The minor gain in weight savings isn't really a primary objective on a 4500lb vehicle, it's more of a bonus of going from Lead Acid to Lithium.

The RE-START partition and going LiFePO4 are the primary goals.

 

[ngng]

Do we have any additional testing information on the battery?

 

[tom @ eas]

Do we have any additional testing information on the battery?

Nothing exciting, other than performing problem-free so far after 3 months, Still gathering data.

 

[Flybyglass]

Any issues yet running the 51R in a Tesla (Model 3/Y). What is the latest software running in the test vehicle?

 

[tom @ eas]

Any issues yet running the 51R in a Tesla (Model 3/Y). What is the latest software running in the test vehicle?

Currently running 2022.12.3.20 and have had no issues. Still collecting data.

 

[geordi]

@tom @ eas - If you have need for a pre-refresh model S beta tester, I would be interested in participating. Just got the latest software yesterday and a service center informed me that Merlin was complaining about my 3 month old lead battery (that they had installed) tossed an error at them when I arrived at the service center's geofence. They did an inspection and said it was fine.... Don't know what they looked at or what it was complaining about.

I do have 12v accessories wired in - but everything is respecting the car's power setup, I tapped the rear window heater circuit at the fuse box for my trailer light isolator and auxiliary outlet. That auxiliary outlet is powering my USB-C to my laptop (100w) then in the regular socket I have chargers for my ipad, external speaker, and Milwaukee 12v battery charger. Overhead powered from the mirror's circuit, I have my radar detector, dash camera, and a Netgear hotspot.

Think I'm stressing that 12v battery at all? I'd be surprised if it was more than 200 watts in total.

 

[tom @ eas]

@tom @ eas - If you have need for a pre-refresh model S beta tester, I would be interested in participating. Just got the latest software yesterday and a service center informed me that Merlin was complaining about my 3 month old lead battery (that they had installed) tossed an error at them when I arrived at the service center's geofence. They did an inspection and said it was fine.... Don't know what they looked at or what it was complaining about.

I do have 12v accessories wired in - but everything is respecting the car's power setup, I tapped the rear window heater circuit at the fuse box for my trailer light isolator and auxiliary outlet. That auxiliary outlet is powering my USB-C to my laptop (100w) then in the regular socket I have chargers for my ipad, external speaker, and Milwaukee 12v battery charger. Overhead powered from the mirror's circuit, I have my radar detector, dash camera, and a Netgear hotspot.

Think I'm stressing that 12v battery at all? I'd be surprised if it was more than 200 watts in total.

I would watch the 12V Milwaukee charger, those can pull quite a bit of amps.

 

[geordi]

No, this is the 12v batteries and the 12v charger that charges from any micro USB connection. So it's not pulling more than 12 watts.

 

[DCGOO]

Bummer this isn't available for <MY22 models Tesla's.

That is because the low voltage system in 2022s has been changed to 15.5 volts, and with a very unique Tesla only lithium battery.

 

[nitrous]

This is still a ~30aH battery, right? I mean all the hype of Cold Cranking Power (1200Amps) aside, it’s a 30 amp hour battery, right?

 

[gearchruncher]

The new Tesla one or the Antigravity?
The new Tesla Li-Ion is 99Wh, so about 6.5Ah.
The Antigravity is an LFP battery rated 30Ah, but the voltage curve is different than a Lead Acid so you may not get that when used in a Tesla that believes it's a Lead Acid.

 

[geordi]

Do we know what the Tesla DC/DC converter logic is, and how much of the 12v battery it is actually programmed to utilize? That it is a 30 amp hour battery might not be significant if it is only using 10 amp hours before turning the charge converter back on.

I do know from Tesla service that when the car is below 20%, it stops supporting the 12v battery at all - and that is what is powering the computers. So if there's an issue with that low voltage battery.... You have a bricked car until that low voltage power is back.

 

[Flybyglass]

Do we know what the Tesla DC/DC converter logic is, and how much of the 12v battery it is actually programmed to utilize? That it is a 30 amp hour battery might not be significant if it is only using 10 amp hours before turning the charge converter back on.

I do know from Tesla service that when the car is below 20%, it stops supporting the 12v battery at all - and that is what is powering the computers. So if there's an issue with that low voltage battery.... You have a bricked car until that low voltage power is back.

In the Owners Manual the only specification is minimum 33Ah 12 volt battery.

 

[gearchruncher]

Do we know what the Tesla DC/DC converter logic is, and how much of the 12v battery it is actually programmed to utilize? That it is a 30 amp hour battery might not be significant if it is only using 10 amp hours before turning the charge converter back on.

It does not deeply cycle the battery. The new Li-Ion battery is 99Wh instead of 400+Wh. It's likely that they do only use about 20% of the 30Ah lead acid, as most LA's don't like to be deeply discharged, and Tesla knows this.

I do know from Tesla service that when the car is below 20%, it stops supporting the 12v battery at all - and that is what is powering the computers. So if there's an issue with that low voltage battery.... You have a bricked car until that low voltage power is bac

This flat out isn't true. Tesla service is often wrong. If this was true, the internet would be full of stories saying that they left their car with 15% charge for 5 days and came back to a completely dead car, but still with 10%+ on the main pack once they jumped it. I've never once heard of that.
This is just a tech making up stuff around the things like the fact that camp mode turns off at 20%. Which is documented in the manual. If the 12V battery non-maintenance happened, that would be in the manual too, and the car would warn you strongly when you got out below 20%.

 

[ElectricLove]

The minor gain in weight savings isn't really a primary objective on a 4500lb vehicle, it's more of a bonus of going from Lead Acid to Lithium.

The RE-START partition and going LiFePO4 are the primary goals.

What value is a jump-start feature in these vehicles? Are you intending to jump other vehicles with it? Or is the idea that it is a 2nd 12V battery that can get the car running if the primary 12V fails (like carrying a jump-pack I suppose)?

 

[android04]

What value is a jump-start feature in these vehicles? Are you intending to jump other vehicles with it? Or is the idea that it is a 2nd 12V battery that can get the car running if the primary 12V fails (like carrying a jump-pack I suppose)?

Their Re-start feature reserves part of the battery's capacity that can't be used unless you explicitly enable it to jump start your own car. It's supposed to replace having to carry a jump pack or get a jump start from someone else.