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Ohmmu battery installation by mobile ranger
- Thread starter EVChris
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Ostrichsak
Well-Known Member
Short answer: No.
Long answer: there are several different firmware profiles a tech must set just for the minor variances that exit in the only-slightly-different factory AGM batteries that they install. If a tech arrives to change out the 12v battery and has one of the newer/different batteries than what's in the car currently, they also have to go through the service/diagnostics panel to select the proper 12v battery profile as part of the installation. Since there isn't a profile engineered for these Lithium 12v batteries they literally can't install it properly. If a Tesla Mobile Tech can't, neither can you. Not to mention there is zero benefit in an EV like a Tesla from these batteries. In an ICE car you needs tons of amperage to turn over and crank an engine. In a Tesla all they do is power 12v accessories. Your turn signals aren't going to blink better because you have this snake oil installed. This has been covered extensively if you want to use the search function.
Conclusion: If you think slapping a Li-Ion battery in w/o any regard for the BMS is a good idea.... well, I guess you're the ideal Tesla owner customer that Ohmmu preys upon to sell their snake oil. If I were you I'd suggest selling on Craigslist and just going with a factory 12v battery replacement. Let the tech come install it inexpensively and go on with your life knowing that you just saved hundreds on something that literally brings you no benefit and could actually harm your reliability.
Long answer: there are several different firmware profiles a tech must set just for the minor variances that exit in the only-slightly-different factory AGM batteries that they install. If a tech arrives to change out the 12v battery and has one of the newer/different batteries than what's in the car currently, they also have to go through the service/diagnostics panel to select the proper 12v battery profile as part of the installation. Since there isn't a profile engineered for these Lithium 12v batteries they literally can't install it properly. If a Tesla Mobile Tech can't, neither can you. Not to mention there is zero benefit in an EV like a Tesla from these batteries. In an ICE car you needs tons of amperage to turn over and crank an engine. In a Tesla all they do is power 12v accessories. Your turn signals aren't going to blink better because you have this snake oil installed. This has been covered extensively if you want to use the search function.
Conclusion: If you think slapping a Li-Ion battery in w/o any regard for the BMS is a good idea.... well, I guess you're the ideal Tesla owner customer that Ohmmu preys upon to sell their snake oil. If I were you I'd suggest selling on Craigslist and just going with a factory 12v battery replacement. Let the tech come install it inexpensively and go on with your life knowing that you just saved hundreds on something that literally brings you no benefit and could actually harm your reliability.
I understand your short answer.
But I did do a search and yours is the first post I've seen which calls Ohmmu snake oil. By comparison, I've seen several posts saying that even getting a Tesla compatible 12v from Tesla was an ordeal, that the factory battery was often not available. The battery is one of the few parts which need to be replaced (tires, wipers, ?) and yet is a pain to replace. Most ICEs make the 12v easy to replace.
Also, Tesla itself recently started using Li+ batteries in the S. So the idea of using Li+ isn't zero benefit.
insideevs.com
But I did do a search and yours is the first post I've seen which calls Ohmmu snake oil. By comparison, I've seen several posts saying that even getting a Tesla compatible 12v from Tesla was an ordeal, that the factory battery was often not available. The battery is one of the few parts which need to be replaced (tires, wipers, ?) and yet is a pain to replace. Most ICEs make the 12v easy to replace.
Also, Tesla itself recently started using Li+ batteries in the S. So the idea of using Li+ isn't zero benefit.
Tesla Model S News and Reviews | InsideEVs
Get the latest on new Tesla Model S models including first drives, in-depth reviews, concept car photos, new features, recalls and more.
insideevs.com
Ostrichsak
Well-Known Member
You can't compare Tesla changing to a lithium 12v battery with PROPER battery management systems in place to what you're talking about. It's not even remotely close. It would be the same as removing your headlight LEDs or HIDs (depending on what version car you have now) and duct taping laser points into your headlight housings and then bragging because you have "laser" headlights much like the newer cars. lolI understand your short answer.
But I did do a search and yours is the first post I've seen which calls Ohmmu snake oil. By comparison, I've seen several posts saying that even getting a Tesla compatible 12v from Tesla was an ordeal, that the factory battery was often not available. The battery is one of the few parts which need to be replaced (tires, wipers, ?) and yet is a pain to replace. Most ICEs make the 12v easy to replace.
Also, Tesla itself recently started using Li+ batteries in the S. So the idea of using Li+ isn't zero benefit.
Tesla Model S News and Reviews | InsideEVs
Get the latest on new Tesla Model S models including first drives, in-depth reviews, concept car photos, new features, recalls and more.
Getting a 12v replaced by Tesla is hardly an "ordeal" so I'm not sure where you read that. In fact, it's FAR and away the easiest way to replace your 12v battery and ends up being only a few bucks more than you can source the same battery and replace it yourself. It's a no brainer. I wouldn't do an Ohmmu even if it was the same price but it's not. It's anywhere from 3-4x more plus you have to install it yourself and roll the dice on Tesla not covering 12v items under warranty because you powered them off of a 3rd party aftermarket battery.
In the end, it's just not worth the headache. You will literally get ZERO benefit to going with Ohmmu in a Tesla. None.
I'm pretty sure that Tesla won't install that battery for you. I replaced mine about a year ago with an OhmMu. I'm pretty sure the OhmMu has a BMS. Mine is still working fine here in the FL heat. It's not that hard to do yourself, but earlier cars with the battery under the cowl is a bit of a pain. Plenty of Vids on the change out process. I had my car in for warranty work and there wasn't any mention of using an aftermarket battery. I know they had to disconnect it for the warranty service.
Just posting my experience for you...
Kaveman
henderrj
Active Member
Not to be rude, but, this is just nonsense from a person who has no idea what they're talking about.
I've had the model S that Sean used when he first developed the battery, complete with its prototype 12 volt lithium-ion battery, for nearly 4 years, after I bought the car from Sean. I've put more than 200,000 miles on the car and that 12 volt lithium ion battery is still working fine.
Tesla service has gone through two full inspections on the vehicle and has no problems with the battery at all. If you don't know what you're talking about, please don't say anything. And, in case you want to worry about it, I get no money or any other compensation from Sean or the folks that now own his company. I just know that the battery has been great from personal experience.
Not only have I never had to replace it but when my son managed to run the HV battery down to zero, he sat for more than 2 hours waiting for the tow truck to come get him. That battery lasts a long time! He did manage to run the 12 volt battery dead as well, a simple jump and now, a year and a half later, the battery is still doing fine. Don't know what their new batteries are like, but I can't imagine they're worse than the prototype.
To the op's question, I know many people have replaced their own 12 volt battery. It doesn't make a whole lot of difference as to the settings. But, you can find lots of threads about it here on this forum.
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Ostrichsak
Well-Known Member
Just saying "not to be rude" doesn't negate rudeness. Especially when the next words are to say that my factual post is "nonsense from somebody who doesn't know what they're talking about" before going on some meandering word wall that doesn't dispute a single thing that I actually said. The reason you don't dispute anything that I actually said is because everything that I said is 100% accurate.
Tam
Well-Known Member
I thought the advantages are:
1) Lighter: measured by DragTimes
AtlasBX that comes with Tesla =28lbs7oz
While Ohmmu=11lbs2oz
That's a saving of about 17 pounds 5 ounces!
2) Longevity: It's 4-year full replacement warranty.
3) It's possible that 12V lithium is snake oil but it seems the idea is endorsed by Elon Musk who told Sandy Munro that "with the new S/X we're also finally transitioning to Lithium-ion--12 Volt".
Ostrichsak
Well-Known Member
1) 17 pounds of weight savings on a 5,000-lb vehicle is the definition of irrelevant. Especially when it's not unsprung weight.
2) Other than a vocal minority on this and other forums, most people generally tend to get about the same service life out of the current Tesla factory 12v batteries. Paying 3-4x times more for the same service life doesn't make any mathematical sense at all. Especially when there is zero performance gain during that service life. Oh, and you have to do the labor yourself for the honor of only paying 3-4x more for roughly the same service life.
3) It's snake oil in the sense of slapping it in a car that wasn't designed for it in the first place. It's going to require some sort of battery management system to compensate for the fact that lithium-ion battery cells require a very specific temperature range to function properly. Without engineering a car from the beginning with one in mind it doesn't make sense.
henderrj
Active Member
Obviously you've never owned one, have no data whatsoever to work with, and just want to pontificate on your idea. As it happens, I do own one, I've put way more time and miles on it than anybody claims to get out of the 12 volt lead acid batteries normally used, and so have many, many other people. Obviously, you do not know what you're talking about. You haven't done any research, you don't quote anyone who has, you simply blast out with statements, without actually having supporting data.
For you to disparage a company this way is just wrong. Look, we all make mistakes, I've certainly made my share. But this one I have actual data about. So do many other people. It isn't just a few people who say this is something that works, many people find it to be cost effective, and a ton less work to deal with in the long run. Let it go, this time you're wrong. I'm sure you'll be right about something else.
In regards to "engineering a car from the beginning", the 12V battery appears to be almost an afterthought in the original design. Here are two good discussions on the strengths and weaknesses of the 12V battery system in the Tesla
Tesla Model S 12V battery analysis
Pros and Cons of Li+ 12V battery replacement. Especially this post from the thread.
The 12V battery as the "achilles heel" of Tesla have been discussed here and other sites extensively. From a personal experience (two Teslas, 150k+ miles) I can attest to the fact that the 12V lead acid batteries Tesla used/uses have to be replaced more often than lead acid batteries on ICE vehicles.
From a technical perspective the 12V charging system doesn't handle 12V lead acid battery charging particularly well. At least with respect to battery longevity.
Here's a graph of the 12V charging system that I recorded from the CANBUS. This is a roughly twelve hour plus cycle. But is representative of what is observed in longer time frames. The two big things on this graph:
1. The voltage repeatedly spikes to ~15V for substantial periods of time. This causes gassing and premature failure of sealed lead acid batteries. (This would be ok for a flooded lead acid battery where you can replace the water boiled off.)
2. The majority of time is spent at 14V. This is kinda low to fully charge the battery, but kinda high for long term float voltage (Low to mid 14's would be better for charging. 13.5 would be better for float.)
Ostrichsak
Well-Known Member
So a doctor an oncologist who's never had cancer themselves can't know anything about it? What a stupid statement. That's almost as stupid as saying that Tesla uses lead acid 12v batteries during your personal attack rant about how little I know. Maybe it's you who should have a better idea what you're talking about before talking on a subject just because you were duped into spending money on something that's of no use in a Tesla.
ucmndd
Well-Known Member
My original OEM battery that was delivered with the car is 4.5 years old now and going strong at 120k miles. I’m far from an anomaly.
“Way more time and miles” is pure hyperbole and confirmation bias. You’ll certainly never realize the ~4x more you’d need to justify the price.
Ostrichsak
Well-Known Member
Nice try trying to make it seem like ~15v is so dangerous and detrimental to lead acid batteries (which we are NOT talking about here in a Tesla... once again) when an ICE car with a healthy alternator/charge system will regularly maintain the 12v battery at 14.4v at most any revs above idle. All the time when in motion. Those aren't just exploding left and right over decades of deployment. This is standard, common every day stuff here so trying to inject hyperbole to make you seem like you have some useful data is only making you look less informed.
I also love how you post the same link multiple times to make it seem like you have SO much data. lol
Your 12v battery analysis link is mostly irrelevant being as it uses an outdated (2014) an inferior Tesla 12v battery for testing. This is a big reason why there have been not one but two new versions since the version that was tested in that link.
Your other link is laughable. The person posting it cites three main "advantages" so let's examine those, shall we?
Reason #1: Less weight. ROFL Seriously? As I already mentioned 17lbs savings of sprung weight nearly dead center mass in something like a 5,000lb car is the definition of irrelevant. You want to pay $300 premium to save 17lbs on a 5,000lb car? By all means... it's your money. But acting like this is some revolutionary advantage that Tesla owners are missing out on for only 3-4x more than the stock replacement is disingenuous at best and deceitful with a likely ulterior motive of self-gain at worst.
Reason #2: Size. It fits the stock location... just like the stock battery. Seriously? Who thinks this is any kind of advantage? This is a joke, right?
Reason #3: and this one is my favorite I think... people try to act like the Ohmmu will somehow make their turn signals flash better or their windshield wipers clean more. Haha... it's ONLY function in a Tesla is to power the 12v accessories. Nothing more. In an ICE car it's a high-amperage draw application so I could see someone touting the benefits to crank of a large displacement V8 (good luck if you're in a cold climate since there's no BMS though) but in a Tesla it's pure snake oil.
The amperage demands in a Tesla on the 12v battery compared to an ICE car is night and day. In a Tesla, you just need somewhere in the neighborhood of 12v for the accessories to function. The amperage is not even an afterthought in this system. The linear way that the AGM factory batteries fail over time allows the car to tell you when your 12v battery is on the way out. Often times, months before it actually fails. These instances of instant failures of 12v batteries in Teslas w/o any indication in advance is greatly overblown and the few instances can be tracked back to a bad batch of batteries that Tesla installed from the factory which prompted one of the revisions.
Why are we still talking about this? This has got to be one of the dumbest topics people bring up on Teslas as some sort of improvement over the original design. Are people really THAT desperate to throw their money away?
Tam
Well-Known Member
I am willing to throw my money away in exchange for less frustration. It's not fun each time when I had to get a tow.
My 2017 Model X had been towed twice for 2 different 12V battery replacements. 1 original + 2 replacements = 3 batteries in 4 years one so far.
My 2018 Model 3 only needed tow 1 time for 1 12V battery replacement. 1 original + 1 replacements = 2 batteries in 3 years.
Those tows are very disruptive.
Dukeybootie
Member
Not sure where the claim of "3-4x more" expensive is coming from, as Mobile Ranger OEM 12V replacements in my area are ~$250 and I paid $500 installed for my Ohmmu. But whatever, I am not going to waste my time arguing with certain parties over the Ohmmu. Anyone who wants to know more about my completely trouble free Ohmmu experience over the past 17 months and 25000 miles can feel free to message me directly.
So the OhmMu 12v was $399 delivered. I had it installed this morning at Luscious Garage in SF for $91 for a total of $490.
Installation took an hour and I grabbed a latte across the street since I couldn't wait at Luscious for now due to Covid restrictions.
Nice people.
FWIW, I got my 12v warning maybe last Monday up in Seattle. I did some research and realized my 12v wasn't failing (catastrophic) and that it was aging (a little more left). I therefore took the calculated risk of dealing with the problem back in the Bay Area. I even took a detour out to Eastern Washington, down the Columbia River and then down 97. I also did a little research and decided on getting a lithium. Time will tell.
Installation took an hour and I grabbed a latte across the street since I couldn't wait at Luscious for now due to Covid restrictions.
Nice people.
FWIW, I got my 12v warning maybe last Monday up in Seattle. I did some research and realized my 12v wasn't failing (catastrophic) and that it was aging (a little more left). I therefore took the calculated risk of dealing with the problem back in the Bay Area. I even took a detour out to Eastern Washington, down the Columbia River and then down 97. I also did a little research and decided on getting a lithium. Time will tell.
I have a 2015 and not a 2020. You get a warning on the instrument panel to replace soon. That's if it's a normal wear failure. If you get a catastrophic failure (bad battery), well your car just doesn't start. I had that on my Nissan Leaf and the AAA guy literally jump started it. He said it was fairly common with Leafs and Priuses.
Very happy with my OhmMu BTW.
Very happy with my OhmMu BTW.
where in god's name are they charging that much? i just had my 12v replaced by mobile service in so cal (probably one of the most expensive areas in the country if not *the* most expensive) and total cost was only $121 for battery with installation.
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