Resurrected the 12V battery

[ucf_motorcycle]

I received my salvage model S with light side damage in running condition. The only two error messages were Replace 12V battery soon and Parking Assist disabled.

After going back and forth with a couple of Tesla service centers over the phone I came to the conclusion they won't even sell me a 12v battery.

So then I figured the only other option is the Lipo one which I'm sure is a great battery but at $400 its pricey and I have a few other things to fix on this car so I wasn't too happy about spending a full $400 for essentially a wheelchair battery.

So I pulled my 12v battery out (which is about the hardest car battery removal I have ever done and Ive done a few) its very tight especially with the air suspension.

Once I got it out I saw it was putting out a bit over 13V so I assumed it was getting charged from the main battery. I opened the caps on top and noticed the cells were very dry. I added water and let it sit for an hour. At that point it was at 12.06V. I put it on a slow trickle charge of .5-1 amp for about 20hrs. I pulled it off it showed 13.1V I let it sit an hour and it stabilized right at 12.6.

Reinstalled the battery and no warning. Only have the parking assist disabled now and the body work.

Hope this saves someone a few bucks. Even the factory Telsa battery is overpriced at $140. But the arrangment of the posts and the fact that its so tight in there make it so your forced to buy that specific one.

Any other deep cycle 33AH battery can be had for well under $100.

If I had to do it again I would pull the leads off and the circuit panel on top of the battery. Leave the battery in the car. Pull off the two rubber strips fill with water and charge as I described above. Pulling the battery out and reinstalling was the hardest part.

 

[mspohr]

I received my salvage model S with light side damage in running condition. The only two error messages were Replace 12V battery soon and Parking Assist disabled.

After going back and forth with a couple of Tesla service centers over the phone I came to the conclusion they won't even sell me a 12v battery.

So then I figured the only other option is the Lipo one which I'm sure is a great battery but at $400 its pricey and I have a few other things to fix on this car so I wasn't too happy about spending a full $400 for essentially a wheelchair battery.

So I pulled my 12v battery out (which is about the hardest car battery removal I have ever done and Ive done a few) its very tight especially with the air suspension.

Once I got it out I saw it was putting out a bit over 13V so I assumed it was getting charged from the main battery. I opened the caps on top and noticed the cells were very dry. I added water and let it sit for an hour. At that point it was at 12.06V. I put it on a slow trickle charge of .5-1 amp for about 20hrs. I pulled it off it showed 13.1V I let it sit an hour and it stabilized right at 12.6.

Reinstalled the battery and no warning. Only have the parking assist disabled now and the body work.

Hope this saves someone a few bucks. Even the factory Telsa battery is overpriced at $140. But the arrangment of the posts and the fact that its so tight in there make it so your forced to buy that specific one.

Any other deep cycle 33AH battery can be had for well under $100.

If I had to do it again I would pull the leads off and the circuit panel on top of the battery. Leave the battery in the car. Pull off the two rubber strips fill with water and charge as I described above. Pulling the battery out and reinstalling was the hardest part.

I haven't seen a battery with removable caps in a long time. They all used to be that way but everybody seems to have gone to the sealed batteries. Good to know that this is a possibility.

 

[ucf_motorcycle]

I haven't seen a battery with removable caps in a long time. They all used to be that way but everybody seems to have gone to the sealed batteries. Good to know that this is a possibility.

I think its still considered a "sealed/maintenance free battery" but its got two rubber strips that easily pop off with a thin flathead screwdriver. I would suggest atleast taking a look at the water level before tossing the battery. You may be throwing out a battery that still has life in it.

 

[mspohr]

I think its still considered a "sealed/maintenance free battery" but its got two rubber strips that easily pop off with a thin flathead screwdriver. I would suggest atleast taking a look at the water level before tossing the battery. You may be throwing out a battery that still has life in it.

Good to know. My battery is getting close to three years old and no problems so far but this is a good option. Perhaps the Tesla battery gets heavier use due to more frequent charging/discharging and this might cause water to boil off.
(BTW, the ad that popped up below this page is for 12v 12ah "wheelchair batteries" for $21.95 from "Batteryguy.com"... funny. It must have picked up your reference to wheelchair batteries.)

 

[ucf_motorcycle]

So after about 3 weeks without issue I noticed severe Vampire loss of about 10mi a day. Suspecting the 12v battery to be an issue again I unplugged the negative side terminal and tested the voltage and it was about 8volts.

I am trying to charge it back up again but in the meantime I ordered the replacement lithium one from BattMobile.

I never did get the replace 12v message again but suspected it wasn't doing well because of the vampire loss.

 

[jjh1234]

If you are going to add water to the battery, it's good practice to use distilled water.

Add distilled water to any cells in which the level of electrolyte isn't touching the bottom of the fill port. Use only distilled water. The minerals in tap water will eventually reduce a battery's capacity. If your battery is one of the so-called low-maintenance varieties, you may not see any filler caps.Mar 28, 2006
Basic Battery Care - Popular Mechanics
www.popularmechanics.com/cars/how-to/a265/1608582/