The 12 Volt Battery

[spaceballs]

Re-reading this thread The 12 Volt Battery - Page 6

Battery is basically gel cell battery i.e. UPS battery, I never get more than 3 years out of that type of class battery before they start to significantly loose capacity.

 

[Mitrovic]

Mine lasted about 4 years...

 

[Doug_G]

My first battery lasted two years.

 

[markwj]

My first one lasted 1 year. The replacement is 3 years so far.

I was told that some 12V Roadster batteries were from a bad batch with poor quality (around 2010/2011 timeframe), but those should all have died by now and been replaced.

 

[ekotysh]

I was just at the Burlingame center discussing what happens in the event 12v starts to lose juice and the tech from the Burlingame service center revealed a neat trick. If your 12v battery starts to malfunction, open and close the charging cap 10 times. It will apparently cause the main battery pack to kick in instead. Of course, this is just for that instance. You will still need to replace the 12v, but at least saves the moment.

 

[roblab]

I was just at the Burlingame center discussing what happens in the event 12v starts to lose juice and the tech from the Burlingame service center revealed a neat trick. If your 12v battery starts to malfunction, open and close the charging cap 10 times. It will apparently cause the main battery pack to kick in instead. Of course, this is just for that instance. You will still need to replace the 12v, but at least saves the moment.

Charging Cap? Huh? Like the Charge Port Door? Or some cap on the 12 volt battery? Open with the charge cord? From the seat, then get out and close it.

Sorry. I don't get it. Please explain this.

 

[ecarfan]

I was just at the Burlingame center discussing what happens in the event 12v starts to lose juice and the tech from the Burlingame service center revealed a neat trick. If your 12v battery starts to malfunction, open and close the charging cap 10 times. It will apparently cause the main battery pack to kick in instead.

By "cap" do you mean the charge port door?

That is a really odd "feature"!

 

[Doug_G]

12 quick cycles of the charge port door cause the Roadster's main VDS computer to reboot.

 

[Botbldr45]

Opening and closing the charge port door once, twice, whatever it takes, will wake up the main battery and the car will work normally. A low or dying 12 volt battery needs to go to Service ASAP for replacement. Charge port trick just allows you to get there.

 

[ekotysh]

Yep, the charge port door.

 

[tennis_trs]

Opening and closing the charge port door once, twice, whatever it takes, will wake up the main battery and the car will work normally. A low or dying 12 volt battery needs to go to Service ASAP for replacement. Charge port trick just allows you to get there.

Yeah, I found the charge port door opening and closing work-around on my own. I believe it just took one open close cycle for mine. Before I found that, the key unlock button would take minutes to unlock the car with the 12V battery dead or close to dead. I went a few months with a dead 12V battery. Tesla had told me that there was no safety concern (I'm not sure if they were right about that), just the inconvenience. Surprisingly, they didn't suggest the charge port door work-around.

 

[jaanton]

When my battery was weak just trying to open the door, pressing the button, would wake up the car (you could hear the circulation pump start) and then if I waited about 20 seconds then the car would unlock with the key button. I believe that the main pack wakes up including the DC-to-DC converter which then needs a few seconds to load enough charge into what was left of the 12v battery. While the charge port door trick probably also works, I bet it really is just taking time for the 12v to get a little power built up.

FYI: my 12v lasted about 3 and a half years. It only really failed when the car had sit for about a month unused. I suspect that sitting unused let it drain when it normally was constantly topped off.

 

[Doug_G]

I just replaced my Roadster's 12V battery. There is some confusion on the thread about what type of battery to get. Here's a picture of the battery I replaced, complete with its part number...

PTX9-BS

 

[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.

I just did a quick search to find some instructions on how to replace the 12 volt battery. Read through the whole post before realizing that I was the one who posted it back in 2012 Looks like I got about 3½ years out of the Batteries + replacement, and 3½ years for the original.