So you're saying that Tesla would "help" a lead acid battery that was old, by blasting it with a 20 amp load to below 12.6 volts? That would be recipe to force an earlier failure.
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Update on replacing OEM 12v lead-acid battery with lithium?
- Thread starter Pianewman
- Start date
I have my old Tesla lead acid battery sitting around and I took a look at the voltage on it and the highest I could get the voltage with the charger is 12.8 volts. So an old battery makes no sense because an old battery would not be able to get anywhere near 14.6 volts.
stopcrazypp
Well-Known Member
No, I'm not saying it's "helping" it, I'm saying it may be trying to detect if the battery is on the way out. Also 20A is nothing to a Lead acid battery, although that may be a different case for a lithium.
There were other threads that discussed how to monitor the lead acid battery to detect if one is going out and the only passive solutions people have mentioned are bluetooth monitors, but those only monitor the voltage and don't really tell you about battery health. The only real test mentioned that might are regular load tests. This tells you the real battery capacity and thus you can judge battery health.
stopcrazypp
Well-Known Member
A typical lead acid battery charging cycle has the battery charging to 14.4V, 14.6V absorption, and it may even go higher for equalization/desulfation.
https://chargetek.com/assets/equal.pdf
The 12.8V you are looking at I presume is the voltage after you take it off the charger. If you monitor the actual charging with multimeter (assuming your charger doesn't have a display), you should be able to see it get to 14.x voltage. If it can't handle that it's probably already a bad battery. Tesla is trying to detect PRIOR to it reaching that state. That's the hard part.
No, im not. Not for a model 3 or Y, which is what the cost is for those vehicles.
The $250 cost is for model S and X, but that is not the discussion in this subform. The fact that it appears you are trying to tell me what I paid is "lucky", along with the fact that your account is brand new and has no posts on any topic except this one really looks like you have a specific agenda, though, which is what your posts look like.
So it's "anti-consumer" because Tesla won't let you replace a $85 battery with a $120 battery? Good luck convincing a judge of that. And you shouldn't be comparing $250 (SLA + install labor) to $120 (lithium battery only) - apple/oranges (labor/no labor). For every one person who is upset because they can't use an unsupported lithium replacement, there are 1000's who are better off because the car will detect a failing 12V early and not strand them. Sounds like a win for the consumer.
I agree with @stopcrazypp - Tesla added a function to load test the lead acid battery to improve early detection of a failing lead acid battery. You're trying to use an unsupported replacement in a system that wasn't designed for it.
TL;DR - "Doctor, it hurts when I do this." / "Then don't do that."
Here's a typical contactor (and one that Tesla has used).
The pick-up current is 3.9A for a maximum of 0.075 seconds. The holding current is 0.23 amps.
The contactor coils in Teslas absolutely do not draw 1000A or even 100A.
Yes, 100% I have an agenda. I would like to replace my Model 3 12v lead acid battery because having to deal with a car failure situation every 3 years when the lithium technology exists at a very low price that prevents this situation from coming up ever again is worth a little effort on my part. I've replaced the lead acid batteries on a couple other cars that are older and lithium works perfectly. Every legacy charger I've tried with lithium batteries work perfectly. So I found it a little surprising that a Tesla Model 3 is the only car I've found that doesn't support lithium 12v batteries. KInda odd. Being a person with expertise in electronics and software, and being a DIY fixer of pretty much anything, I've always enjoyed figuring out why something doesn't work. I would think a lot of Model 3 owners would support the effort I'm putting forward to pressure Tesla to fix this shortcoming in their firmware.
Any Model 3 owners for getting Tesla to fix the firmware so Lithium batteries will work and we''ll all have a much higher capacity battery that you will never have to change again?
My work is not stopping anyone who likes replacing their 12v battery every few years from continuing to do so.
There is no " your Work" here though. Feel free to continue to pursue this through tesla, or sue them or whatever, thats up to you. You should contact the makers of the battery you bought, whatever it is, and pursue them putting pressure on Tesla or something, but there isnt going to be an ongoing bumping of threads here for it.
The long term discussion thread for this topic is here:
Longer term Ohmmu experiences?
Does the OHMMU App periodically let you know if there's a newer firmware available or do we need to just check it periodically? The app doesn't say that I can tell, but anytime you update, it pulls the most recent from the server. Looking at the Ohmmu site, the latest BMS firmware is V29.bin...
teslamotorsclub.com
I would suggest participating in that thread as ohmmu is one of the makers of third party lithium ion batteries that have issues in model 3s and you may have like minded people in that thread. Any further discussion on the topic should be moved to that thread.
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The reason I came here with this issue:
- Tesla has no mechanism to report a new issue. I took my car into the support system to address this issue and it was a complete waste of time talking to support people who can only repeat what they've been told to say. They told me the only solution was to put in another 12v lead acid battery.
- I figured others might be interested getting this improvement made to Tesla firmware so they never have to replace a 12v battery again.
But I'm done with this topic unless somebody asks be a direct question about it. A lot of people seem to have the attitude that the Tesla is perfect and the Model 3 is perfect and anybody who points out an issue MUST be wrong. I get it, I love my Model 3 too, but it sucks to have that battery issue pop up at the worst possible time when you're out in the middle of nowhere and your cell phone battery is dead and the car refuses to charge the cell phone because of this 12v issue...
Nope--that's the wrong interpretation of this. It's not that we are saying they are perfect, but you are saying they need to try to fit a square peg into a round hole, and they are defective for not doing that. For the newer vehicles Tesla makes that are BUILT WITH the lithium batteries, they treat the lithium batteries like lithium batteries. For the older models of cars that were BUILT WITH lead acid batteries, they treat them like lead acid batteries. It's not any more complicated than that. The behavior of what they do to them will be different because that is what kind of part it is supposed to be.
I have a lot of gripes at them for several other things, but this one just doesn't make sense.
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