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12 volt battery options

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AFAIK the Hankook AtlasBX maintenance free (MF) 85B24LS (45Ah)12V flooded lead acid battery is the only battery that will fit the 2020/2021 Tesla Model Y vehicle (with the terminal posts in the correct orientation.) As far as capacity the AtlasBX lead-acid battery rated 45Ah has more capacity than the 15V lithium battery (7.5Ah) even accounting for using more of the lithium battery's capacity before recharging.
 
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The Tesla 12V battery is covered under the standard Tesla vehicle warranty for 4 years/50k miles. If the 12V battery fails or the Tesla vehicle displays the message that it is time to replace the 12V battery then Tesla Mobile Service (where available) will bring and install a replacement 12V battery of the same type. (You can't install the new 15V lithium battery module as a replacement for the 12V MF lead-acid battery.)
 
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Definitely not an AGM battery. AGM batteries are clearly marked as AGM. 12V AGM batteries have different charging requirements and float voltage requirements from 12V flooded lead-acid batteries. AGM batteries can be easily damaged by overcharging and by maintaining the battery at too high a float voltage.

The Tesla 12V battery is maintenance free (MF) meaning it is a sealed, flooded lead-acid battery. The MF battery does not require you to check the electrolyte level of the six individual cells within the battery and add distilled or de-ionized water,as needed, to the battery.

AGM batteries are also maintenance free. AGM batteries can be installed in any orientation (even on its side or upside down) and can be installed below the rear seat, hatch floor or trunk. (This is considered part of the passenger compartment.) Due to the risk of caustic battery electrolyte being widely disbursed as a result of an accident that ruptures the battery case MF batteries, as with other flooded lead-acid 12V starter batteries must be installed forward of the firewall in what would be the engine bay of a traditional ice vehicle. A similar rupture of the case of an AGM battery would result in a very small quantity of electrolyte leaking from the battery.
 
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I just hit 2 years on my OEM 12v battery and scheduled a mobile service appt. for replacement - quoted $110.40 total. At that price it's worth the peace of mind as I have a long road trip planned in Sep and this desert heat eats batteries quickly. Had considered the OHMMU but considering the price and possible trouble with software updates it's not worth it.
 
I was banking on OHMU too, until Tesla effectively killed them. I thought the OE battery WAS an AGM...? No? I'm just over one year, and have the messege that it's time.
If your 1 year old Model Y has less than 50k miles then Tesla will replace the battery under the vehicle warranty. You can open a service request using the Tesla app, explain that your Model Y displayed a message that it is time to replace the 12V battery. Tesla Mobile Service should be able to come to your home or workplace and install the replacement 12V battery. Until you can schedule the replacement, hopefully a week or so, you might want to keep a small lithium 12V jump starter pack on hand in case you need to jump start the vehicle. Keep the jump starter out of the vehicle or in the frunk as you won't be able to unlock the Tesla vehicle if the 12V battery completely fails before you can obtain the replacement 12V battery. If the 12V battery fails you can release, open the frunk using a 9V battery by touching the 9 Volt battery + and - terminals to the wire leads hidden behind the front tow hook cover. (Or so I have read.)
 
No, I don't think they will cover it under warranty. Subwoofer upgrade, though it's tied into the inverter, not directly to the battery. Never an error code. Never a drain. Technically should not be affecting the 12 volt at all.
I expected a little less life on the 12 volt, but not this much less. And as I said, had planned on Ohmu when it was time. I don't really care about the warranty, don't mind purchasing one, just wanted a better one.
I talked to the Tesla service advisor about the changed BMS settings, rendering Ohmu batteries non-functional. He confirmed that it was NOT a byproduct of another software update, but instead, a purposely executed plan to stop people from purchasing Ohmu batteries....lost revenue fur Tesla, obviously. This tells me that the Ohmu situation won't get solved, no matter how many signatures they get on their petition. He just smirked, and told me that the only way to get a LiOn 12-volt is to trade the car in for a newer model. There are no plans fur Tesla to offer one for older models. I told him thanks, but if I DID trade my Tesla, it wouldn't be for another Tesla.
So...looks like I'm purchasing another 12 volt battery from the Continental Tire Company. Sigh.
Oh, and if it IS a rebranded battery from Continental, can anyone tell me, with certainty, who makes it?
 
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I'll never understand anyone modifying ANYTHING in the electrical system of any car and then wondering about issues. I've done it, so I know the consequences. It's the simplest "warranty" claim to decline, and you're correct that they probably won't cover it.

I wouldn't trust the opinion of ANY service advisor with ANY car company regarding administrative decisions that are WAY up the food chain.

A quick Google search:

Incline Equity Partners
(“Incline”), a Pittsburgh-based private equity firm, is pleased to announce the sale of Continental Batteries (“Continental” or the “Company”), a leading distributor of aftermarket batteries to the automotive, commercial, electric utility vehicle, marine and industrial markets.Jan 21, 2021
 
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With Tesla changing the software of the BMS to stop people from purchasing OHMU batteries, are there any battery options at all for earlier versions, other than the wimpy factory battery made by a tire company?

Or is the only option to trade in the car on a newer one to get the LiOn 12-volt battery?
There's nothing wrong with the OEM Tesla 12v battery and Tesla will sell them to you. When Li-On 13v batteries die, they are dead unlike 12v lead acid/AGM which tend to fade and show symptoms of impending failure. Our 2017 Model S OEM lasted over 5 years and when it started showing symptoms we proactively replaced it with the Hankook 12v Tesla sells now. The original OEM battery still takes and holds a charge.
 
I am NOT surprised that battery life was effected. I'm just surprised at how much. It is a tiny digital amp, fused at 15AMPs. Even at volume, it draws less than 6amps. About the same as a radar detector. As I said, I'm perfectly willing to purchase a battery, and know better than to even try a warranty claim.
And yes, I did the same "quick Google search" . I just found it hard to believe that a private equity firm is producing batteries.
Come down off the horse and stop the self important pontificating. If you want to add something helpful, please feel free
 
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"Helpful": Do NOT believe a service advisor for any information about corporate decisions that are way above his paygrade. His opinion would be pure speculation.

"Helpful": The "private equity firm" isn't producing the batteries. They are simply marketing them. Again, it's SOP in the corporate world.

I guess you already know this, as well. Three main auto battery manufacturers in the US: Johnson Controls, which supplies more than half of the market; Stryten; and East Penn.

Sorry if this info pisses you off. You keep asking questions, but maybe I should assume you already know the answers?
 
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