12V Lithium battery from BattMobile experiences

[Beryl]

I have three years and 100,000 miles on my original battery, so this is far from foregone.

Your car is newer and may have had the newer battery. As I memorialized, the rep informed me that I had the older battery installed twice (originally and first warranty replacement). They didn’t tell me if they installed the old one the 3 time. It is entirely possible that those old ones are carried around for warranty replacements.

 

[Only Trons]

BLUF: In my early 2013 RWD Tesla Model S, I just replaced the Tesla-installed DCS 12V battery with the Lithium version from Ohmmu. In spite of what their website states, this is not a simple “drop-in replacement.” The replacement battery does NOT fit as a simple “drop-in replacement” due to a different spacing between the negative terminal center and the side of the battery case. I am providing this information as a service to others who may be considering purchase of this battery.

DETAILS: My April 2013 RWD Tesla S received a 12v battery alert in early December, informing me that the 12V battery needed to be replaced “soon.” My first 12V battery lasted about 3 years, and was replaced in mid 2016 by Tesla under warranty, at no cost to me. The replacement battery lasted about another 3 years – I received the recent 12V battery replacement alert in late December 2019. Mileage: 62,000 miles.

Using the Tesla app, I scheduled an appointment to replace the battery. Tesla scheduled a mobile appointment for mid January. Several days later, I received an update from Tesla informing me that no 12V batteries were available, and my appointment was now rescheduled to late January, after new batteries were expected to arrive. Given my recent (and many) interactions with Tesla service for both my Tesla vehicles, I became concerned about their ability (and reliability) to meet this new re-scheduled date. I understand that a 12V battery alert doesn’t mean the battery will fail within a few days; but there are no guarantees (or hard data that I’m aware of) that indicates when the battery might completely fail. I did not want my spouse to be stuck somewhere away from home if the 12V battery failed.

I had read much about the Lithium variant offered by Ohmmu. They offered a battery that was clearly advertised on their website as a “drop-in replacement” for the Tesla Model S. Based upon those assurances, I purchased a battery with the idea of replacing it myself. Granted, I was aware of the extremely tight area in which the battery was installed – I had seen it myself when a mobile ranger came to my home to replace the charge port and opened up the frunk trim in order to disconnect the HVIL. I knew I was in for an extremely challenging remove-and-replace event.

After removing the old battery (with lots of grunting, straining, and use of language which my mother would not approve), I installed (i.e. shoehorned) the Ohmmu battery in place. After installing the battery hold down bracket, and the breakout fuse panel on top of the battery, I discovered that the negative battery cable lug did NOT line up with the negative terminal on the new battery. No amount of coaxing, adjusting, prying, or cussing worked. I tried adjusting everything I could think of. Finally I decided to re-measure ALL the battery dimensions. To my surprise, I discovered a difference in the distance between the negative battery terminal bolt hole and the side of the battery case. In the old battery, the distance was 0.75 inches. In the replacement Ohmmu battery, it was 1 inch. This means the negative battery cable must move “inward” by 0.25 inch in order to be connected to the battery terminal bolt hole. That may not sound like much, but it resulted in interference between the battery cable terminal and the breakout fuse panel cover. I contacted Ohmmu by email; they responded immediately suggesting I rotate the battery cable lug. I had already tried that, but I tried again with no success. Finally, I resorted to modifying the breakout fuse panel cover by trimming. I was careful to ensure that no terminals or electrical connectors were exposed. Still; this should not have been required. I informed Ohmmu of what I had to do in order to make this work; their response was: /quote: “Sorry for the inconvenience, each vehicle year/model has some subtle nuances and we try to do our best to support all instances but there are outliers.”/ Interestingly, their web site quotes glowing reviews; however, I did not find a means to post a direct review.

I’ve attached photos to help illustrate.

I was able to make this new battery fit. I feel the website description as a “drop-in replacement” was misleading at best. I can only hope that their description of performance and reliability are indeed accurate.

For those of you with older Tesla Model S, I suggest you keep this in mind if you are thinking of taking on the replacement of the 12V battery yourself.

 

[rsg123]

Can all the other Ohmmu users who experienced a drop-in experience with the battery post their Model S’s month and year of production? I’m curious to know when the change happened that made it easier to replace. When my October 2014 S needs a new battery I will likely go this route, but only if it’s smoother than @Only Trons’s experience.

 

[cookie99]

View attachment 498687 BLUF: In my early 2013 RWD Tesla Model S, I just replaced the Tesla-installed DCS 12V battery with the Lithium version from Ohmmu. In spite of what their website states, this is not a simple “drop-in replacement.” The replacement battery does NOT fit as a simple “drop-in replacement” due to a different spacing between the negative terminal center and the side of the battery case. I am providing this information as a service to others who may be considering purchase of this battery.

DETAILS: My April 2013 RWD Tesla S received a 12v battery alert in early December, informing me that the 12V battery needed to be replaced “soon.” My first 12V battery lasted about 3 years, and was replaced in mid 2016 by Tesla under warranty, at no cost to me. The replacement battery lasted about another 3 years – I received the recent 12V battery replacement alert in late December 2019. Mileage: 62,000 miles.

Using the Tesla app, I scheduled an appointment to replace the battery. Tesla scheduled a mobile appointment for mid January. Several days later, I received an update from Tesla informing me that no 12V batteries were available, and my appointment was now rescheduled to late January, after new batteries were expected to arrive. Given my recent (and many) interactions with Tesla service for both my Tesla vehicles, I became concerned about their ability (and reliability) to meet this new re-scheduled date. I understand that a 12V battery alert doesn’t mean the battery will fail within a few days; but there are no guarantees (or hard data that I’m aware of) that indicates when the battery might completely fail. I did not want my spouse to be stuck somewhere away from home if the 12V battery failed.

I had read much about the Lithium variant offered by Ohmmu. They offered a battery that was clearly advertised on their website as a “drop-in replacement” for the Tesla Model S. Based upon those assurances, I purchased a battery with the idea of replacing it myself. Granted, I was aware of the extremely tight area in which the battery was installed – I had seen it myself when a mobile ranger came to my home to replace the charge port and opened up the frunk trim in order to disconnect the HVIL. I knew I was in for an extremely challenging remove-and-replace event.

After removing the old battery (with lots of grunting, straining, and use of language which my mother would not approve), I installed (i.e. shoehorned) the Ohmmu battery in place. After installing the battery hold down bracket, and the breakout fuse panel on top of the battery, I discovered that the negative battery cable lug did NOT line up with the negative terminal on the new battery. No amount of coaxing, adjusting, prying, or cussing worked. I tried adjusting everything I could think of. Finally I decided to re-measure ALL the battery dimensions. To my surprise, I discovered a difference in the distance between the negative battery terminal bolt hole and the side of the battery case. In the old battery, the distance was 0.75 inches. In the replacement Ohmmu battery, it was 1 inch. This means the negative battery cable must move “inward” by 0.25 inch in order to be connected to the battery terminal bolt hole. That may not sound like much, but it resulted in interference between the battery cable terminal and the breakout fuse panel cover. I contacted Ohmmu by email; they responded immediately suggesting I rotate the battery cable lug. I had already tried that, but I tried again with no success. Finally, I resorted to modifying the breakout fuse panel cover by trimming. I was careful to ensure that no terminals or electrical connectors were exposed. Still; this should not have been required. I informed Ohmmu of what I had to do in order to make this work; their response was: /quote: “Sorry for the inconvenience, each vehicle year/model has some subtle nuances and we try to do our best to support all instances but there are outliers.”/ Interestingly, their web site quotes glowing reviews; however, I did not find a means to post a direct review.

I’ve attached photos to help illustrate.

I was able to make this new battery fit. I feel the website description as a “drop-in replacement” was misleading at best. I can only hope that their description of performance and reliability are indeed accurate.

For those of you with older Tesla Model S, I suggest you keep this in mind if you are thinking of taking on the replacement of the 12V battery yourself.

View attachment 498686

it looks like the test car they used was a refreshed front bumper model S, and yours may be slightly different because of the age? I wonder if all the glowing reviews are from customers with newer cars than yours. They definitely should took more into it instead of shrugging you off

 

[beatle]

The dual motor cars (pre-refresh) also have their batteries in a different, more accessible place. It's basically right in the middle of the car behind the frunk.

 

[ElectricLove]

I want to reply here for Ohmmu on this; we have had hundreds of similar vehicles (pre-2014) upgraded with our battery. In only one other case (that we were made aware of) was it necessary to make adjustments to make the battery fit. In that case the “fix” was to rotate the terminal 90 degrees and then bolt the adapter back onto the top of the battery. Cutting wasn’t necessary. This vehicle was a salvaged vehicle and had used a non-OEM 12V battery previously which may or may not be related to the issues (was installed remotely by customer).

When a customer does an install we do our best to support them and try to respond quickly and be helpful to them. We strive to ensure that everyone is taken care of as quickly and satisfactorily as we possibly can!

Certainly, I can understand your frustration with the process not going as smoothly as you had hoped. And I can definitely understand the frustration with the battery not fitting in your particular vehicle. The early edition Model S can be so difficult to reach the battery due to the placement underneath things and tucked away in the corner like it is!

In this case, however, we would have never recommended you make a cut on that plastic fuse holder on top of the battery. And no one else should have to do that, ever. It may have been necessary to adjust the other terminal to allow the battery to move forward under the fuse box and provide adequate clearance. Hard to be certain remotely.

In retrospect, I do believe we should have had a higher level of communication on the matter to troubleshoot the installation, even tho we responded quickly I would say we didn’t respond thoroughly enough to empower your process. For that I apologize, you deserved better! I hope you enjoy the benefits of the battery over the long-haul and it gives you many years of performance!

Note to others; your best way to communicate with Ohmmu quickly is via web chat found on the bottom right corner of Ohmmu website! (www.ohmmu.com)

 

[Only Trons]

In response to @ElectricLove :

There was ABSOLUTELY no slack available to rotate the terminal 90 degrees. Just to ensure I am clear, there was NO -- repeat -- NO slack available. And your statement that "it may have been necessary to adjust the other terminal" isn't the answer either ... assuming you mean the positive terminal, I tried that also.

I suppose I could have asked for Ohmmu to refund my purchase monies and pay for return shipping since the battery was not as advertised (e.g. not a "drop in replacement") -- but I would have been left with my failing 12V battery with no known replacement availability date from Tesla. And since I didn't ask that question of Ohmmu, I don't know what response I might have received.

The purpose of my providing this information is to tell early Model S owners of this conflict. They can choose how to deal with it. It appears that AWD versions of Model S won't experience this issue.