Model 3 subwoofer install.

[23adrock]

Hmmm...well, given that some people have had very early battery failures, I have to wonder.

It is interesting that we’ve identified at least two separate problems with the Tesla-supplied lead acid-battery: the first being premature failure, and the second being some sort of negative effect on the sound system (you’ll just have to take our word for this one ).

Makes me wonder if 1) There’s some sort of inherent problem with the Tesla-supplied lead-acid batteries, or 2) Something about a Tesla does not play well with lead-acid technology.

 

[tlr1000]

Ohmmu should do some scientific testing and publish. I think most agree that better power = better sound so the question remains does the upgraded battery provide better power delivery compared to a perfectly functioning OEM battery? I'd guess yes.

 

[tlr1000]

I tried my own experiment tonight. Mind you, my stock lead-acid battery is fine. But I put a LiPo jumper on it, opened the doors, cranked the stereo, then switched the LiPo on and off to see if I could hear a difference. I could not. And I have pretty sensitive hearing from work in music production.

Thanks for trying that. How big was the jumper you used? Did it have similar capacity to the Ohmmu battery?

 

[grmdl3]

Thanks for trying that. How big was the jumper you used? Did it have similar capacity to the Ohmmu battery?

It's a 24Wh LiPo pack, with very short (6 inch?) leads.

 

[tlr1000]

It's a 24Wh LiPo pack, with very short (6 inch?) leads.

I don't know what the Ohmmu Model 3 battery specs are but any idea if the capacity of your pack is similar? If your pack has more capacity or less than the Ohmmu that could make a difference as well.

 

[jamnmon66]

I have a theory about this that might explain everything. Just a guess but let me float the idea. I love the sound system in my car. I've even listened to some dance music because the bass sounds so good... not normally in my wheelhouse. Applause from Lady Gaga sounds REALLY good on that system... definitely not normally in my wheelhouse. I used to do high end stereos in my cars in the '90s like many of you and I have experience with amps and large capacitors. And, my wife's previous car was an Infiniti G37 with the premium audio (we both have Model 3s now). The stereo in the Infiniti was good but the premium audio Tesla stereo is definitely better.

In my 3, several times, I have had the bass suddenly disappear and the audio sounded flat. Sometimes it was a few seconds and other times it was for an entire drive and it went back to normal the next drive. We all know the car is monitoring the voltage in just about every circuit. I'm sure that includes the 12-v power from the 12-v battery. What if when the car senses a lower voltage (but not low enough to cause a failure to start or send an error code), it cuts power to the amp(s) to protect the 12-v battery? Maybe those who are reporting a big difference with the Ohmmu battery had an original 12-v battery that put out slightly lower voltage than what was expected by the car, but not low enough to cause any problems starting. Or, if the voltage sensor on the circuit was slightly out of spec, or both. Then, the higher, more stable voltage from the higher quality 12-v battery eliminated that problem and everything sounds the way it does for the rest of us. That would explain those reporting an improvement and also those who are skeptical that the new battery would make any difference.

I'd be curious if someone else with a factory battery would meet up with 12adrock, or someone else who has reported a sound improvement with the new battery, to see if there's any difference. Maybe you unlucky few just got a factory battery that was subpar but not bad enough to cause a failure.

EDIT: BTW, we both have 2018 LR RWD Model 3's with the factory 12-v battery.

 

[tlr1000]

We will never know until someone does a back to back test that includes a full test of the OEM AGM battery to confirm it is within spec. If the OEM AGM battery is below spec, regardless if it is only weeks old, then a new Ohmmu would likely make a positive difference. The money is if there is a noticeable difference from a within-spec OEM battery.

 

[23adrock]

I have a theory about this that might explain everything. Just a guess but let me float the idea. I love the sound system in my car. I've even listened to some dance music because the bass sounds so good... not normally in my wheelhouse. Applause from Lady Gaga sounds REALLY good on that system... definitely not normally in my wheelhouse. I used to do high end stereos in my cars in the '90s like many of you and I have experience with amps and large capacitors. And, my wife's previous car was an Infiniti G37 with the premium audio (we both have Model 3s now). The stereo in the Infiniti was good but the premium audio Tesla stereo is definitely better.

In my 3, several times, I have had the bass suddenly disappear and the audio sounded flat. Sometimes it was a few seconds and other times it was for an entire drive and it went back to normal the next drive. We all know the car is monitoring the voltage in just about every circuit. I'm sure that includes the 12-v power from the 12-v battery. What if when the car senses a lower voltage (but not low enough to cause a failure to start or send an error code), it cuts power to the amp(s) to protect the 12-v battery? Maybe those who are reporting a big difference with the Ohmmu battery had an original 12-v battery that put out slightly lower voltage than what was expected by the car, but not low enough to cause any problems starting. Or, if the voltage sensor on the circuit was slightly out of spec, or both. Then, the higher, more stable voltage from the higher quality 12-v battery eliminated that problem and everything sounds the way it does for the rest of us. That would explain those reporting an improvement and also those who are skeptical that the new battery would make any difference.

I'd be curious if someone else with a factory battery would meet up with 12adrock, or someone else who has reported a sound improvement with the new battery, to see if there's any difference. Maybe you unlucky few just got a factory battery that was subpar but not bad enough to cause a failure.

EDIT: BTW, we both have 2018 LR RWD Model 3's with the factory 12-v battery.

Yeah that’s why I was wondering in my post #141 above if there was something wrong with some OEM Tesla batteries that lead to both the stereo issue and the early failure issue that many report.

it’s also interesting that I came from a premium G37 and felt my Tesla’s sound was far inferior at first, whereas you felt like it was an upgrade. Could again argue for a defective battery on my end.

However I must point out that there’s not a single post from anyone who upgraded to lithium who said the bass did NOT improve (other than the one who used a jumper, which of course isn’t an exact test). But my observation could also involve significant selection bias, since those without the battery issue would never be motivated to change the battery out in the first place since their stereo always sounded good.

I still have my (five month old) OEM battery, is there some test that I could do on it? I only have a multimeter tho, in case more sophisticated testing equipment is needed.

 

[tlr1000]

All you can do with a multimeter is check voltage. That is a good indicator but a proper battery tester will look at other factors as well like internal resistance. Lots of battery testers on Amazon and if you have a garage that you have a relationship with they may do it for free. Another option is to go to a dedicated car battery retailer as they will likely have the tester sitting on their sales counter ready to go. It literally takes seconds to get a readout on the health of the battery.

If you get you battery tested, please let us know the results as it would help clear up some questions.

 

[jamnmon66]

I still have my (five month old) OEM battery, is there some test that I could do on it? I only have a multimeter tho, in case more sophisticated testing equipment is needed.

If you have a charger, you could charge the factory battery and put it back in as a test. If my theory has any weight, maybe the charge would bump the voltage high enough to make the sound system work as designed. Since you have a meter, check the voltage of the factory battery before and after charging and compare it to the OHMMU.

 

[jamnmon66]

It could have something to do with resistance as well as for what the car is sensing. I think a battery increases in resistance as it ages (read that somewhere IIRC). See if your multimeter will give you an ohm reading across the terminals of each battery & compare. I think the battery installed in the car will have to be disconnected for a valid comparison.

I've never tried to test a battery like this before. Hopefully it doesn't hurt your meter (edit: I mean when set up to measure resistance) . Doesn't seem like 12-14 volts would hurt it but I'm not an expert. Maybe someone who knows more will chime in.

 

[jamnmon66]

All you can do with a multimeter is check voltage. That is a good indicator but a proper battery tester will look at other factors as well like internal resistance. Lots of battery testers on Amazon and if you have a garage that you have a relationship with they may do it for free. Another option is to go to a dedicated car battery retailer as they will likely have the tester sitting on their sales counter ready to go. It literally takes seconds to get a readout on the health of the battery.

If you get you battery tested, please let us know the results as it would help clear up some questions.

LOL, didn't read this post before my last reply. This sounds like a better idea than mine.

 

[Idkorcare]

You could just toss the old battery back in and see how its voltage does compared to the Ohmmu. The whole 12v battery system is a little odd at least what ive run into. If the voltage drops low enough i think on wake the penthouse stops supplying power and you get battery warnings, happened when i ran the batt down to <12v. Otherwise when you wake up the car it charges the whole system around 14.7v for awhile before at the very least lowing the battery down to 13.8v.

if you have sentry or overheat protection on the penthouse will stay or come on randomly, but i dont have anything tracking the car to see if it wakes itself for any other reason not to mention I always leave my car plugged in.

I did retry wiring my aftermarket system straight off the battery and turns out that at a certain point if you pull to much power off the 12v batt the car with simply stop charging it possibly a fuse/ breaker tripping, this doesn’t immediately set off any warning lights and once the load is removed it starts receiving a charge again.

none of that really answers any of these questions but was interesting to find out. Also if you never traced power from the penthouse to the 12v batt. It runs off the penthouse up the passenger side to VC_Right then to VC_Front then to the 12v battery.

 

[Ravire]

I keep reading about how the lithium 12v improves the sound so I’m going to buy the Ohmmu and see if it makes a difference with the stock system. If not I’m planning on getting a Reus audio system installed and I’ll see if that functions better with the lithium battery vs stock. If that still doesn’t show a difference I guess I wasted $400. With the stock mxm4 tires I don’t notice a difference in handling when carrying stuff in the frunk so I doubt the weight savings will be noticeable considering it’s like less than half a percent of the cars weight.

I’ll use a multimeter to check the voltage of both batteries out of the car and I’ll do a frequency sweep at the same set volume in the car and I’ll use a phone app to see a spectrum for both. I picked my car up in March the day after it was delivered from the factory so the battery should be good but I’ll make sure. I’ll also put the original battery back to make sure changing the battery doesn’t just refresh something to cause it to play different.

Posted this in another thread but I’ll post results here too when I have them.

 

[23adrock]

If you have a charger, you could charge the factory battery and put it back in as a test. If my theory has any weight, maybe the charge would bump the voltage high enough to make the sound system work as designed. Since you have a meter, check the voltage of the factory battery before and after charging and compare it to the OHMMU.

Thanks. I’ll see if I can get my hands on a charger.

 

[jamnmon66]

Thanks. I’ll see if I can get my hands on a charger.

tlr1000 had a good idea about taking it to a retailer. It's been a long time since I needed it but the auto parts store used to test, condition & charge a battery for free if I left it with them. Might be worth a try.

 

[Ravire]

Posted this in another thread but I’ll post results here too when I have them.

So after spending a week with the lithium battery and then switching it to the lead acid battery I do hear a difference but it’s a very small one and not worth buying the battery just for this change. All the changes I’m about to list are slight changes but the system has an overall warmer sound signature and the treble does not sound as harsh to me as it did before. That’s the biggest change for me but the bass also does seem slightly more punchier but this can just be placebo. After the virus settles down hopefully I can arrange a blind listen with another model 3 owner. The main issue I have with the sound system is how on certain tracks the sub just can’t hit the notes due to not being able to play that low. I’m going to install an aftermarket sub to fix this and I can also test if the lithium battery makes a bigger difference in that setup.

 

[Ravire]

When the Ohmmu arrived it was at 13.2 volts and when I pulled the lead acid battery out of the car it measured at 13.03 volts after sitting for around 3 hours. After a week it was at 12.98 volts and remained steady. When both batteries are in the car they stay energized around 13.56-13.57 volts.
Battery Tests

 

[TheD]

I just read through this thread because I want to install a subwoofer. All was going well until someone mentioned installing an Ohmmu battery. Now I’m totally tempted to start there and then upgrade my sub. I too had a 1 farad cap in the 90’s and know the difference it made.

I just wanted to chime in and add that my December 2019 built Model 3 already had the 12v battery replaced once (I blame a faulty dashcam install). I remember the tech had to unplug a cable under the rear seat to replace the 12v battery. In any case, my audio and bass performance did not improve with the new battery. In fact, I would argue there was no change whatsoever. As an audiophile and coming from an amazing Bowers & Wilkins system (and previously Focals), the premium audio system leaves much to be desired.

After reading through this thread, I think I am going to purchase an Ohmmu because I don’t want to risk getting an error after installing a sub. If there is an improvement in soundstage and the highs lose the harshness I am hearing, this will be an added bonus. If the bass response improves, even better! The way I see it, if the battery makes the stock sub sound better, my aftermarket JL sub will definitely see an improvement.

I will share my feedback after swapping out the battery.

 

[Ravire]

I just read through this thread because I want to install a subwoofer. All was going well until someone mentioned installing an Ohmmu battery. Now I’m totally tempted to start there and then upgrade my sub. I too had a 1 farad cap in the 90’s and know the difference it made.

I just wanted to chime in and add that my December 2019 built Model 3 already had the 12v battery replaced once (I blame a faulty dashcam install). I remember the tech had to unplug a cable under the rear seat to replace the 12v battery. In any case, my audio and bass performance did not improve with the new battery. In fact, I would argue there was no change whatsoever. As an audiophile and coming from an amazing Bowers & Wilkins system (and previously Focals), the premium audio system leaves much to be desired.

After reading through this thread, I think I am going to purchase an Ohmmu because I don’t want to risk getting an error after installing a sub. If there is an improvement in soundstage and the highs lose the harshness I am hearing, this will be an added bonus. If the bass response improves, even better! The way I see it, if the battery makes the stock sub sound better, my aftermarket JL sub will definitely see an improvement.

I will share my feedback after swapping out the battery.

I honestly think the change was more from the speakers breaking in rather than the battery, I have a jl sub installed and the battery doesn’t seem to make a difference now