The 12 Volt Battery

[Doug_G]

How difficult is it to access the battery? The picture is good - I just don't know how much it took to access it.

Pretty easy. Pop the front right wheel off, remove the wheel liner, and there it is. I could easily replace it with tools already in my garage.

 

[dsm363]

Maybe Tesla should replace it at the 2 year interval then. I would probably save them money sending out Rangers for these 12V problems. Is this common or does it just seem that way since it happened to my car?

 

[W.Petefish]

Or have the option of relocating it to the trunk so it could be easier replaced and allow US to replace it.

 

[daniel]

Yeah. I'm wondering if Tesla should just replace them with the annual service or find something longer lasting.

They heard you! The ranger replaced my 12-v battery today as part of my first annual maintenance, just because he said they've been failing. He said the original one was a cheap Chinese one. He said the one he put in today is better.

Expect a new 12-v battery at your next annual maintenance.

Edit: I wasn't having any trouble with it. He just said the old ones are not great so he was putting in a better one.

 

[augkuo]

Aw, crap, mine just went 'fault' this morning.

Car still operates just fine - just getting a warning every time I get in to it.

same here - no problems with the key fob though

 

[dsm363]

same here - no problems with the key fob though

Hmm. That's strange. I forgot to try the OVMS but I tried everything else (opening up charge door and closing it, clicking unlock and waiting a few seconds..etc) and couldn't get it to unlock with the key fob. I just got the new 12V battery Monday so I assume I got the new one but am not sure. Everything works again.

 

[markwj]

Key fob is still working for me, even though 12V failed warning is up every time. Rangers replacing it on Tuesday (after the long holiday weekend here).

 

[djp]

I've had my car in storage over the winter. Yesterday I took it out for a quick errand and got the "12V Service Required" message. The car has been sitting for a couple of months and the 12V battery hasn't had many charging opportunities so I'm not surprised it was low. I did a 12A 120V charge on the ESS to let the 12V battery trickle-charge for 8 hours - problem solved.

This is a good reminder for anyone who is storing the car: do a couple of long charges to keep the 12V battery topped up.

 

[JohnGarziglia]

What is the nominal voltage of the auxiliary batter when it is not receiving a charge from the main battery pack? Mine is at 11.6 volts which seems low. Is that normal or is 11.6 volts indicating an impending failure? It has been replaced once but that replacement was more than a year ago and more than 15K miles ago.

 

[ggr]

My understanding is that a healthy and charged battery should be between about 12.6 and 13.2 volts. It sounds like it is on its way out.

 

[vbsdan]

I just replaced mine today. It's a pretty simple job, remove the right front wheel, then remove the access panel that's secured with (I think) 8 bolts and 3 nuts. There are a total of 4 bolts at the top, 2 that are obvious and 2 more a little farther up. I found it to be a bit easier to remove the headlight access panel too (2 more bolts) because you need to slide the main access panel around a little to get it out and with the headlight panel removed you can see what you're doing a little better. I still had my original Chinese battery in there so it made it 3½ years. It's a standard size motorcycle battery, 12v 8AH. I picked up a US made replacement at Batteries Plus for about $80.

I had my annual service about 6 weeks ago, then about a week later started seeing the "12 volt battery needs service message". I'm not sure if they would have replaced it at no charge as part of the annual service since my car is out of warranty.

Anyway, it's an easy job, about an hour, not worth taking the car in or paying for a Ranger visit.

 

[augkuo]

I just replaced mine today. It's a pretty simple job, remove the right front wheel, then remove the access panel that's secured with (I think) 8 bolts and 3 nuts. There are a total of 4 bolts at the top, 2 that are obvious and 2 more a little farther up. I found it to be a bit easier to remove the headlight access panel too (2 more bolts) because you need to slide the main access panel around a little to get it out and with the headlight panel removed you can see what you're doing a little better. I still had my original Chinese battery in there so it made it 3½ years. It's a standard size motorcycle battery, 12v 8AH. I picked up a US made replacement at Batteries Plus for about $80.

I had my annual service about 6 weeks ago, then about a week later started seeing the "12 volt battery needs service message". I'm not sure if they would have replaced it at no charge as part of the annual service since my car is out of warranty.

Anyway, it's an easy job, about an hour, not worth taking the car in or paying for a Ranger visit.

Otherwise it's a $500+ job, $131 for the battery and 2 hours of labor

 

[Smop]

Has anyone replaced their battery with a 14+ ah battery? I have had bad luck with the Tesla 12v batteries (3 replacements in 2 years). Anyone have any recommendations of a reliable 12v battery. I know that Odyssey makes great automotive batteries not sure about who makes the best motorcycle ones? BTW some weird things happen once the 12v starts to fail (random error messages and weird car behavior). From my experience it seems as if electric cars are harder on 12v batteries compared to ICE vehicles (have 6 ev's and all of them have had some sort of 12v battery problem- or seemingly unrelated problem that has been solved once the 12v battery has been replaced).

 

[marco2228]

Does anyone know, if there is no 12V battery in the Roadster 1.5?
I don't find it. So either it's in a different place or there simply is no 12V battery in the 1.5's...

 

[jordanthompson]

Otherwise it's a $500+ job, $131 for the battery and 2 hours of labor

Actually its $271.81 (battery and labor) in Miami. I told them I will replace it myself ($80 for exact replacement from Interstate Batteries.)

 

[djp]

Does anyone know, if there is no 12V battery in the Roadster 1.5?
I don't find it. So either it's in a different place or there simply is no 12V battery in the 1.5's...
View attachment 34553

Not in the 1.5s, the 12V system taps directly into the main battery pack. The 2.0 added a separate 12V battery behind the front wheel well on the passenger side.

 

[Dr. John]

My 12 v battery has been dying for the past 2 months and I just replaced it yesterday. You must jack up the R front end and locate your two chucks for the tire lug nuts in your tool kit. Get the Interstate motorcycle battery #FAYTX14 $80. (4"x6"x3.4" roughly) first. With tire off you can pry off the splash guard after removing 3 nuts. Easy to tear the rubber/plastic trying to pry it off over the bolts. Then there are about 7 or 8 bolts to remove the lower front plastic panel. You can leave the headlight fabric panel in place and pull it up and out of the way. Replace battery and close up. There was a coupling wire harness above the battery with no attachment. Don't know what it is for, I left it alone. Time about 1 to 1.5 hours. Roadster Vin ***717. Kalamazoo

 

[smorgasbord]

Has anyone replaced their battery with a 14+ ah battery?

I'm wondering as well. I'm over 30K miles and 35 months - doing annual service next month. I'm on the original 12v battery. Afterwards, assuming Tesla doesn't replace it, what should I do to test it? Is there room for a larger 12v battery (I've got a v2.5) in there, and if so, what are the ramifications of "upgrading" the battery on the rest of the electrical system?

 

[dsm363]

They should replace it. I thought they were replacing them every 2 years anyway. Could just ask them to check it and see what they say.

 

[Jaff]

I just looked into this and was told by Tesla that I should not use a 12v battery exceeding 8 ah under any circumstances.

I was getting 12v errors due to the new sound system I had installed (my Tesla 12v battery is only a year old as I replace it every 2 years)...I am installing a separate, 12v 40 ah lithium battery in the trunk to power the sound system...I am also looking at replacing the Tesla 12v 8 ah battery with a Lithium alternative...I have been told that a minor alteration would have to be done to the bracket that holds the battery as the Lithium battery has a slightly smaller footprint...although this "Smart" brand Lithium battery costs about twice as much as the Lead one, it should last far longer (they advertise 10x more cycle charges than Lead batteries), and weighs significantly less (under 2 lbs.)

Smart Battery® 12V 7AH Lithium Ion Battery

this is the battery that will power the sound system... Smart Battery® 12V 40AH Lithium Ion Battery

The battery for the sound system is not linked to the ESS, so I will have to charge it separately a few times / week (as required)...from my inquiries, it appears that installing a separate battery to power your sound system is really the only way to achieve powering an enhanced sound system

I'm wondering as well. I'm over 30K miles and 35 months - doing annual service next month. I'm on the original 12v battery. Afterwards, assuming Tesla doesn't replace it, what should I do to test it? Is there room for a larger 12v battery (I've got a v2.5) in there, and if so, what are the ramifications of "upgrading" the battery on the rest of the electrical system?