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How does Ohmmu Battery perform in Hot Climate
- Thread starter chumanji9
- Start date
lUtriaNt
Member
go to their site and read what they have to say:
https://www.ohmmu.com/battery-testing
i live in LA and you know how the temps have been. ive had the battery since april and its not broken a sweat in the 115 degree heat we had the last several days.
https://www.ohmmu.com/battery-testing
i live in LA and you know how the temps have been. ive had the battery since april and its not broken a sweat in the 115 degree heat we had the last several days.
I just read that the OEM battery is only $80. If that is true I would not spend $439 on an aftermarket. You could just buy a spare oem or 5.
ucmndd
Well-Known Member
ucmndd
Well-Known Member
It is completely unknown aside from the manufacturer claims. Model 3 hasn't been out long enough to verify their claims.
It's allegedly a LiFePo chemistry that is more tolerant to temperature changes than most other common Li-ion chemistries, but people still recommend not using it in the cold.
It's allegedly a LiFePo chemistry that is more tolerant to temperature changes than most other common Li-ion chemistries, but people still recommend not using it in the cold.
its below 0C (32F) for at least part of the day from October to March/April around here... so that's not good. Its starting to go down into the 30s at the end of this week here...
lUtriaNt
Member
cats who are interested in these lithium batteries should send an email to ohmmu and ask them directly about how their battery handles cold climates. i not saying people here are wrong in their responses, but for something like this, and with a vendor who is quick to respond, id just ask them directly.
I think that's for the LiPo chemistry, not the LiFePo chemistry.
According to Ohmmu's web site, they have testing equipment that is capable of reaching very cold and very hot conditions. Unfortunately, that page doesn't say to what temperature extremes the battery was actually tested to.
Edit: Ohmmu's testing page doesn't say the exact temperatures, it does however say, "Testing has been performed on all products we sell (per IEC 60068-2-1) so we can stand behind our batteries 100%." So I guess we'd need to look up that IEC spec and see what the temperature range is.
IEC 60068-2-1 doesn't require operation during the cold tests. Passing it only means it is operational after exposure, which hardly says anything useful in this case.
The only manufacturer of LiFePo 12V replacements claiming to actually be chargeable below freezing are ones that have a built in heater. Ohmmu is not that manufacturer.
And 5 months is longer than any OEM battery lasted you?
On the asking Ohmmu, as some suggested, I always take the used car salesman's word for things......
When I asked them about using one in Green Bay where it will see -15f every year and colder some years I got, and this is paraphrasing.
"It wont hurt it that much" and "It's close enough to the main pack, that will keep it warm enough"
Tesla engineers have certainly dropped a few balls over the years, that said it is still.worth asking yourself why they do certain things. Like why are the aero wheels heavy? Answer is because when talking long range high speed travel aerodynamics are more important than light weight. How about the lead battery, if anyone could get a lithium battery to work in the application across all climates and then market it as environmentally friendly it would be them.
The original isn't lithium because there are compromises the engineers and bean counters couldn't come to terms on, what do you think those compromises are?
Heh. It's pretty far away from the main pack, especially thermally. Makes you what other claims they make that aren't based in reality, right?
What I find funny (and relevant) is that AGM batteries, the type Tesla is apparently using for Model 3, are noted for being better in hot weather.
Further, the 12V in a Model 3 is seeing nowhere near the temps a 12V in an ICE is. You know, ICE? Combustion? Makes heat! Those things cook in an ICE, and still last longer than they apparently do in Model 3.
So what gives? Clearly, temperature isn't the primary problem. Anyone looking to get an Ohmmu because of high temps should rethink IMO. Tesla is having bigger problems than that, and we don't know if the Li-ion 12V replacements really address that problem (Model 3 hasn't been around long enough, plus we have no idea what the problem is).
webbah
Active Member
I've had mine for 14 months in Switzerland. And I've had no errors (I guess I am a lucky one?) and during winter am often in Zermatt, Verbier, Davos and other areas that are below freezing with the car sitting outside in ski parking areas. Never had any issue.
The recent errors are on some batteries and not all and only due to a recent change Tesla made to the cars firmware due to all the OEM batteries dying fairly quickly. Ohmmu has been working with Tesla and ALSO is acting like a proper company and informed all customers that if they have the issue they will send them a NEW battery to resolve the issue.
Keep in mind that on forums you will hear 90+% people complaining and not people posting positive feedback.
The recent errors are on some batteries and not all and only due to a recent change Tesla made to the cars firmware due to all the OEM batteries dying fairly quickly. Ohmmu has been working with Tesla and ALSO is acting like a proper company and informed all customers that if they have the issue they will send them a NEW battery to resolve the issue.
Keep in mind that on forums you will hear 90+% people complaining and not people posting positive feedback.
And you never had an OEM battery last longer than 14 months?
I used Google and pulled weather averages Verbier came up as "rarely below 7F or above 73f" Chicago came up as "rarely below 5F or above 91F". There is a lot of USA north of Chicago the city I like near comes up as rarely below -7F and rarely above 89F, and there is a lot of the USA that is colder than where i am too and certainly a lot that is hotter.
I looked at the Ohmmu two years ago for my S and they wouldn't give me a temperature they knew it had been successfully used at, yours is the coldest I have seen someone say they are using it and I am gladd it has worked sofar but who is to say it makes it thru another winter.
I know the OEM replaced in my car which is only the second battery the car has had has been fine at -20F.
I don't know the difference between the S and 3 12volt, anyone know if it is the same chemistry?
@camalaio while I agree ICE batteries placed under hood see much higher temps, they are also not subject to the charge cycling a Tesla battery is, I suspect the apparent temperature issue is affected by that.
webbah
Active Member
I replaced mine when the car was only 2 months old for other reasons, primarily as I run 12v equipment in the car that causes drain on the 12v system more than a stock car. I have a Blackvue DR-900S dual channel camera setup (5 watts) and a Teltonika RUT950 automotive Wifi Router hidden inside the center console (also 5 watts).
The Ohmmu holds it's voltage at a more consistent rate over the curve than the OEM battery does so the car sleeps much longer as the HV system doesn't need to wake up to charge the 12v as often as the OEM in this case. The secondary reason was all the annual 12v OEM issues people constantly complain about.
I'm often up in the alps near the Simplon pass and other areas. We can see -10-20C and my car has been fine. The biggest issue is the range is slaughtered. I'll also mention that I've done a lot of soundproofing with butyl and single cell foam in the car which helps retain heat. I've done this in the frunk as well for the frunk lid, firewall and under the frunk. I don't believe it makes a dramatic difference for heat retention when the car is idle and parked however. For the interior though it is great as I use the heater less with less loss through the doors, floor, etc.
I installed a Ohmmu 12V Li ion battery on April 8, 2020 in my M3. Excellent battery. Warranty is exceptional. Live in Tucson where 2 years for lead acid battery is standard. All was well with added amperage giving extra boost to A/C and sound system. Great people to deal with. In early September I started getting a persistent messaged that my 12V needed to be replaced. This was after several OTA updates. The work around is to disconnect and reconnect the 12V and the HV power. That works for a short while then repeat. You cannot install OTA updates while the warning exists. Ohmmu is near to fixing the problem which Tesla created. There will be a free battery exchange. Meanwhile Tesla ignores the problem. My advice is wait until Ohmmu fixes the problem.
The 12V battery has nothing to do with AC. The compressor runs off the high-voltage main pack, and the fans would be largely unaffected by the 12V battery (12V would be supported by the PCS off of the high-voltage main pack any time AC is running, not supported by the 12V battery).
Reminds me of that guy who said he felt the sportier handling and acceleration from the reduction in weight of this battery change.
Placebo effect for the win!
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