I was so frustrated last time my 12V died (service center was out) & I called everywhere trying to find a replacement. Closest I found was at Batteries+ chain: they had similar size but reversed polarity & not enough slack to make it work. So this time I didn’t even hesitate to replace with Ohmmu. Especially in Arizona when it’s hot I want a reliable car so I’m done with crappy half-measures.
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What's with the Ohmmu 12V battery?
- Thread starter camalaio
- Start date
I can tell you as well as others, pulling out that 28 Lbs lead acid battery, Holy Meatballs it’s heavy. The 11 Lbs Ohmmu feels so light compare to the OEM, I like to cut the weight down as much as possible when it comes to EV’s, and also longevity. Suppose to last a lot longer then 2 years which is when the Tesla OEM’s lead acid battery are crapping out. I’ve owned the Ohmmu since April 2019. No issues and will be reporting back in Oct which 1.5 years at that time. Took the car to Tesla over the TeslaCam/Sentry mode issue. Nothing was said about the Ohmmu.
Fred
Knightshade
Well-Known Member
Out of context (and the car) yeah you'd notice the difference- but 17 lbs on a vehicle that weighs 4100 lbs is a difference of 0.4%
No chance at all you could tell the difference if you drove 2 cars identical except for one having a 17 lb lighter battery in it in a blind A/B test. It'd be like a guy saying he can notice a performance difference in his BMW M3 when it's got 10 gallons in the tank vs 12.5 gallons in the tank.
Yes all weight savings is good, but this alone wouldn't be a noticeable difference was the point (esp being non-rotating mass).
Now a noticeable stereo difference? That I could buy... (and would be the reason I'd consider buying one if/when my OEM one dies if it's out of warranty)
smatthew
Active Member
Or just go on a diet.. I'm down 15lbs since the beginning of the pandemic. That almost covers the potential weight savings of a Ohmmu battery!
Oh THAT'S where I got it...
smatthew
Active Member
Oh yes, the age old theory that weight loss is a zero sum game. Sorry buddy, I didn't mean for you to get it. Unless... did you cut me off in February? ;-}
AGM are "sealed" in that they don't need water topped off to maintain them, and are able to recapture oxygen and hydrogen, but they still have a valve and thus must be able to vent to the atmosphere to prevent excess pressure build up in the event of an overcharge. All lead acid batteries installed in a car must have a way to vent outside of the car if they are sealed in a compartment.
AGM is still lead acid.
Knightshade
Well-Known Member
smatthew
Active Member
Without any extra butter please. Don't want to add any weight to my Model 3
android04
Active Member
To those who are looking for an alternative 12v battery for Model 3 in case of emergency, you can go to any auto parts store or big box store and get a Group Size 51R battery that works. They are common in many Hondas but are starting batteries that are not suitable for a long life in a Tesla where a deep cycle battery is more appropriate. My point is that in case of emergency where you might be stranded or might be facing an expensive tow bill, the $150 Group Size 51R battery could save you until you get the $80 OEM replacement from Tesla.
lUtriaNt
Member
spoke with the vendor and they mention this error will pop up just AFTER the update. so if you've not seen it within 2 days you most likely will not see it.
Well, like clockwork with a bit over two years of ownership in hot Florida weather, Mobile Service just came to replace a failed 12V battery under warranty. In a few more years I’ll definitely be curious how people’s Ohmmu’s are holding up and possibly purchase one once my cars warranty expires. Getting stranded every two years unexpectedly isn’t something I’m looking forward to if the trend continues.
With a bit under 2 years with Ohmmu in the Model 3 (2020.28.6 for a week, no errors), mostly unplugged life down to -15F and up to 110F, and v2, v3 supercharging at up to 255kW - knock on wood, zero issues.
A two week notice is customary but not mandatory.
smatthew
Active Member
And then you yell in a rage - "BATTERY, I OWN YOU" and you tighten the battery restrains to emphasize the point.
israndy
Supercharger Hunter
It is kinda surprising that they don't allow connection to the Ohmmu's BMS via some app so you could discover the battery health. Perhaps they figure it will outlast the car, with thousands and thousands of cycles it might.
Ohmmu does have other batteries for RV's that have built in Bluetooth with their pwn app. I connected an antigravity lithium battery monitor to the battery to find what it was doing. Forwarded all to Ohmmu. Ohmmu wrote a note recently that they are considering upstarting production of the V4 again seeking more feedback from testers. Without battery changes or cooperation from Tesla not sure how this would work. I'm wondering of the most recent updates will allow a lithium replacement . I have noticed the voltage charging spikes are much lower now topping out about 14.2 volts fr charging. My most recent experience had the V4 battery at about 14.2 volts resting fully charged and after 6 hours I started getting VCfront errors and after the third one the charging system stopped charging the battery and an active warning stayed present until I swapped back into a lead battery.
israndy
Supercharger Hunter
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