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Replace 12 volt battery

M109Rider

Active Member
Apr 8, 2018
1,489
1,518
Kitchener, Ontario
Oh and the Rear view Camera comes on immediately on reverse now, with the old Lead Acid Battery the rear view camera screen would go black for 3 to 4 seconds before it turned on.

Fred

Hmmm.
I would assume that has more to do with a power reset, rather than the battery having an impact. But who knows.
Still interesting regardless ...
 

Wennfred

Supporting Member
Apr 4, 2019
2,915
1,821
San Diego
Took a drive north to Rancho Cucamonga Superchargers last night, about 123 miles from San Diego, the first stall charged about 32kw so I moved over to the next stall where it took 70kw to start. Temp was 61 degrees, added Homelink yesterday morning in the Model 3 Standard Plus. Ohmmu Lithium Battery still holding up well.

Fred
 
  • Informative
Reactions: Arctic_White

tread

Member
Jul 17, 2018
108
122
Austin, TX
If someone can find the service bulletin and post it I would appreciate it. A week ago I got the 12v replacement message on my screen. My vehicle is a 06/18 manufactured, have had it since 08/18 with only 7k miles. Support says I'll be getting a free replacement under warranty.
 

CapnLoki

Member
May 10, 2018
68
77
Boston North Shore
I don't understand the point of this. There are three basic causes of premature failure - a faulty manufacture (likely in this case), severe overcharging - a dangerous situation with any battery, and chronic undercharging (may be hardware, software, or just plain neglect). I don't see how a $450 battery solves any of these problems.

I would much rather replace the stock battery for $0 and find out if the car itself has a problem. Putting a lithium battery into possibly faulty charging system seems dangerous.

And getting excited about saving 12 pounds on a 4000 lb car is pretty silly, though I appreciate that we do many silly things because it feels good!.
 

hcdavis3

HCD3
Mar 3, 2019
1,814
1,058
02571
I don't understand the point of this. There are three basic causes of premature failure - a faulty manufacture (likely in this case), severe overcharging - a dangerous situation with any battery, and chronic undercharging (may be hardware, software, or just plain neglect). I don't see how a $450 battery solves any of these problems.

I would much rather replace the stock battery for $0 and find out if the car itself has a problem. Putting a lithium battery into possibly faulty charging system seems dangerous.

And getting excited about saving 12 pounds on a 4000 lb car is pretty silly, though I appreciate that we do many silly things because it feels good!.
Morning Cap. I’m curious if the original battery was AGM and the replacement is the same.

Are AGM Batteries Better?
 
  • Informative
Reactions: jkoya

LGA737

Member
Dec 19, 2017
63
233
NJ
The original battery is actually a very cheap (to Tesla) conventional lead-acid battery. Tesla didn’t want to spend a lot of money for a battery that doesn’t really do much other than keep some low-draw electronics running when the main battery pack is off.
 

hcdavis3

HCD3
Mar 3, 2019
1,814
1,058
02571
The original battery is actually a very cheap (to Tesla) conventional lead-acid battery. Tesla didn’t want to spend a lot of money for a battery that doesn’t really do much other than keep some low-draw electronics running when the main battery pack is off.
Thanks LGA. Do you think the replacements are AGM batteries?
 

CapnLoki

Member
May 10, 2018
68
77
Boston North Shore
Morning Cap. I’m curious if the original battery was AGM and the replacement is the same.

Are AGM Batteries Better?
The stock battery is a 45 amp-hour deep cycle AGM battery, value should be under $100. My post concerned replacing it with a lithium ion battery for $450.

The original battery is actually a very cheap (to Tesla) conventional lead-acid battery. Tesla didn’t want to spend a lot of money for a battery that doesn’t really do much other than keep some low-draw electronics running when the main battery pack is off.
An AGM battery is certainly cheaper than lithium, but a good step up from the flooded batteries that are used as starting batteries in most cars. I haven't seen any evidence that lithium is better in this application.
 

hcdavis3

HCD3
Mar 3, 2019
1,814
1,058
02571
The stock battery is a 45 amp-hour deep cycle AGM battery, value should be under $100. My post concerned replacing it with a lithium ion battery for $450.


An AGM battery is certainly cheaper than lithium, but a good step up from the flooded batteries that are used as starting batteries in most cars. I haven't seen any evidence that lithium is better in this application.
Thanks Cap. From what I’ve read Lithium ion 12 volt batteries are sensitive to cold temperatures even though they have some form of BMS built in. Apparently error messages are common.
 

LGA737

Member
Dec 19, 2017
63
233
NJ
You don’t have to take my word for it. Just go look at the battery. It has a vent tube connected to a hose that is routed overboard. AGM batteries are sealed and have no vents. Also consider that all this battery has to do is keep some low power electronics running when the main batteries are powered down. If it gets discharged past a certain point, the main batteries power up and recharge it. Tesla didn’t bother with a more expensive AGM in this application because it wasn’t needed.
 
  • Disagree
Reactions: smatthew

CapnLoki

Member
May 10, 2018
68
77
Boston North Shore
You don’t have to take my word for it. Just go look at the battery. It has a vent tube connected to a hose that is routed overboard. AGM batteries are sealed and have no vents. Also consider that all this battery has to do is keep some low power electronics running when the main batteries are powered down. If it gets discharged past a certain point, the main batteries power up and recharge it. Tesla didn’t bother with a more expensive AGM in this application because it wasn’t needed.
It is a myth that AGM batteries are totally sealed. In fact they must be vented or they would explode in an overcharge event. Many AGM car batteries have a vent that can (must!) be fitted with a vent hose. Lots of discussion about this on various forums such as miata and bmw and examples of AGM sold with vents for fitting in miatas, etc.

To be honest, I couldn't find any conclusive proof one way or another - the vendor (Atlasbx) doesn't list it on their site and I didn't want to pull mine out to inspect carefully. However, there are numerous claims online that this is an AGM, and I couldn't find any sign that it is flooded. A tube is not in any way conclusive.
 

LGA737

Member
Dec 19, 2017
63
233
NJ
Hey I don’t blame you for not believing some random dude on the internet, so no hard feelings. Atlas BX are cheap flooded cell batteries you can get from Menards if you google it. I wish I could share more, but you’re just gonna have to take my word on it, which on the internet isn’t worth very much.
 
  • Disagree
Reactions: smatthew

M109Rider

Active Member
Apr 8, 2018
1,489
1,518
Kitchener, Ontario
Hey I don’t blame you for not believing some random dude on the internet, so no hard feelings. Atlas BX are cheap flooded cell batteries you can get from Menards if you google it. I wish I could share more, but you’re just gonna have to take my word on it, which on the internet isn’t worth very much.

So if one has to replace the 12 volt battery, out of warranty, what is the recommendation. ?
 

LGA737

Member
Dec 19, 2017
63
233
NJ
its gonna be a while before anyone has to replace one out of warranty. Hopefully by then 3rd party suppliers will be cross referencing the part. Otherwise Tesla would be the obvious source.
 

hcdavis3

HCD3
Mar 3, 2019
1,814
1,058
02571
You don’t have to take my word for it. Just go look at the battery. It has a vent tube connected to a hose that is routed overboard. AGM batteries are sealed and have no vents. Also consider that all this battery has to do is keep some low power electronics running when the main batteries are powered down. If it gets discharged past a certain point, the main batteries power up and recharge it. Tesla didn’t bother with a more expensive AGM in this application because it wasn’t needed.
Morning LGA. I’m still curious as to why my battery needed to be replaced. I’ve never had a 12 volt lead acid battery go bad. Any insight?
 

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