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98% for max charge?
- Thread starter Alysashley79
- Start date
aerodyne
2 of 3 EV's - Defect Free!
I tend to agree. Charged the car cold this AM and max charge was 98% on slider. Half an hour later, slider went to 100%.
Well thought I’d revive this old thread I started. I’ve needed to max charge a few times over the past few weeks. My slider says 100% however the car stops charging at 96% and won’t go above that. My 96% is 221 miles which is down from the 241 I had a year and a half ago. I have an appt in two weeks for mcu related things and added this to the schedule but wanted to check here and see if anyone else is still actually seeing this behavior despite doing deep cycle discharges and back up?
Fwiw I was at 18% when I plugged in this morning and still only would go to 96%. This isn’t about the bms being off at this point.
Fwiw I was at 18% when I plugged in this morning and still only would go to 96%. This isn’t about the bms being off at this point.
aerodyne
2 of 3 EV's - Defect Free!
There must be hundreds of posts, advising to charge to 100% or nearly there, and down to 20% or lower in an attempt to rebalance the cells and recalls brste the BMS.
A lot of this advice is coming directly from Tesla SvC reps. The same ones who tell you your USB drive is killing MCU1 eMMC chips.
I have seen zero data showing this helps, apart from the few percent gain that can be attributed to a warmer battery and BMS calibration.
Recent updates run the pumps and fans at 100%, so any gain in battery capacity by charging over 90% to 95% is offset by consumption.
I check the BMS via SMT daily. Really don't recommend this, it is addictive like watching Tesla stock.
The battery is what it is. Keeping it between 20-90% most of the time and as cool as possible, especially when SuC, will reduce degradation, that is a fact. Apart from that, nothing one can do.
A lot of this advice is coming directly from Tesla SvC reps. The same ones who tell you your USB drive is killing MCU1 eMMC chips.
I have seen zero data showing this helps, apart from the few percent gain that can be attributed to a warmer battery and BMS calibration.
Recent updates run the pumps and fans at 100%, so any gain in battery capacity by charging over 90% to 95% is offset by consumption.
I check the BMS via SMT daily. Really don't recommend this, it is addictive like watching Tesla stock.
The battery is what it is. Keeping it between 20-90% most of the time and as cool as possible, especially when SuC, will reduce degradation, that is a fact. Apart from that, nothing one can do.
I completely agree with you. I don’t think doing the deep cycle drains will do jack squat unless you’re actually out of balance which I know can happen. But it’s usually more wheh you lose a few rated miles not a few % off your ability to charge. By taking away my 4% they’ve taken about 12-14 miles of rated range. No it’s not huge. BUT that’s on top of the degredation one would expect out of a 5 year old battery.
Degredation I get. Degredation and loss of ability to max charge is not ok with me. The fact that some still can charge to 100% is also concerning to me.
I don’t expect my car to be like it was off the factory floor. But doing these little hiding things isn’t ok either.
Degredation I get. Degredation and loss of ability to max charge is not ok with me. The fact that some still can charge to 100% is also concerning to me.
I don’t expect my car to be like it was off the factory floor. But doing these little hiding things isn’t ok either.
aerodyne
2 of 3 EV's - Defect Free!
You might have battery gate. The only way to know for sure is have a look at the pack voltages with a CAN bus reader and app like SMT. If your cells never charge more than 4 volts that is probably the case.
Possibly a balance issue. My cells get out of balance a bit, but a charge to 70% or a moderate drive seem to fix that. Most I have seen is 50mv.
You might have a failing string or module. If it dies you get a refurbished pack hopefully.
Possibly a balance issue. My cells get out of balance a bit, but a charge to 70% or a moderate drive seem to fix that. Most I have seen is 50mv.
You might have a failing string or module. If it dies you get a refurbished pack hopefully.
I read above you don't supercharge much, but did you do so recently?
Do you still have the original speed or has it been significantly reduced for you too now ? (ie if starting with SoC below 10%, and warm battery: maybe you hit a few seconds above 120kW, then quickly drop to 90kW or maybe even 70kW or even lower.)
if I have a warm pack at a v2 or v3 supercharger I’ll sit over 100kw until I get to 35% and then it slowly starts to taper. I was at 81% last week and at 56kw. It’s for sure not as fast as say a model y. (Had a loaner a few weeks back and it was at least twice as fast across the same threshold)
aerodyne
2 of 3 EV's - Defect Free!
I’m still also unable to charge over 98%. My slider moves to 100% but won’t charge passed 98%. Can’t believe we still have the same issue a year later. Software obviously not fixing this issue.
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Electric700
Active Member
You should report the issue using the Tesla app and ask them to review it during your next service appointment. It seems like a software update is required.
They’ve ran remote diagnostics at my request at least a half a dozen times and said that it’s out of balance. Clearly it’s not. Lost miles ya ok. Lost miles and percent. Nope. I’ve rebalanced it and still nothing.
this whole thing goes right along side my Emmc that’s causing reboots every week when drive and them telling me it’s just software. (Insert eye roll emoji)
So I've recently made a discovery along with the help of another member on this forum. Essentially, I have a pack or two that slightly lag behind while the other packs reach maximum charge. Now... this could be a pack issue or just a balance issue. I tried to charge to 100% again and it went to 98% and stopped. I drove it down to about 70% within a day or two and then tried to get back to 100%. This time it went to 99%. My next step is, I'm going to lower the amps to charge. I currently have a hpwc and charge at 40amps. I'll drop to 30% and this will hopefully allow the slow pack to keep up with the rest and hopefully balance itself out. I'll report back with my findings when I do this. Alysashely79 do you have Scan My Tesla? This is how i'm seeing my particular problem.
This is the truth (about charging past 90% will activate pumps and fans). Essentially if you charge that high the pumps and fans will consume the battery back down to low 90's if you dont drive it. Charging to 100% is really only beneficial if you plan to jump in right away and take off. Even then, the regen is gone so its almost like wasting energy I suppose.
This is most current response for my issue.
Hello Dan, A technician has completed a diagnosis of your concern and provided the following results; The customer has a slight battery cell SOC imbalance. Looking at the vehicle the customer lowered the charging termination percent to 90% and allowed the vehicle sit connected to the charger for approx. 5 hours. After this we see the imbalance begin to close however while this is the correct method to rebalance a vehicle the amount of time allowed (once for 5 hours) is insufficient in length of time. The process below needs to be repeated every day for 30-90 days and for as long as possible each day. Deep discharging will only increase the range estimate in miles and will not influence the batteries capacity or cell balance. Let the vehicle rest at 90% SOC. Set the charge slider to 90%. Keep the vehicle plugged in for several hours after it reports a complete charge and says it has stopped charging. This will cause the pack to rebalance.
Hello Dan, A technician has completed a diagnosis of your concern and provided the following results; The customer has a slight battery cell SOC imbalance. Looking at the vehicle the customer lowered the charging termination percent to 90% and allowed the vehicle sit connected to the charger for approx. 5 hours. After this we see the imbalance begin to close however while this is the correct method to rebalance a vehicle the amount of time allowed (once for 5 hours) is insufficient in length of time. The process below needs to be repeated every day for 30-90 days and for as long as possible each day. Deep discharging will only increase the range estimate in miles and will not influence the batteries capacity or cell balance. Let the vehicle rest at 90% SOC. Set the charge slider to 90%. Keep the vehicle plugged in for several hours after it reports a complete charge and says it has stopped charging. This will cause the pack to rebalance.
I don’t have scan my Tesla. I’ve been leery to do any of these things since I’m still under warranty BTB until end of may. I’ve done deep cycle dives. I’ve done mid cycle charges. My car at home charges at 40amps but it normally (I’d say 95%) charges on an l2 on the daily so max 32 amps. Cripes I’ve even tried deep cycle dive and 110 charge up which took for freaking ever. I’ve tried it all. 98% is the farthest it will go. I’m going to give it to Tesla next week because I keep getting the black screen and reboots while driving (despite their firmware fix last month) and will see if they can make it get to 100%.
Sorry for being lazy and not re-reading back, but have you tried supercharging to 100%? Also, scan my tesla won't void your warranty. They wont even know its hooked up unless they see the physical apparatus. I always unhook everything before any kind of service so they cant blame any issues on it. Not that it could cause any issues. It really does help you understand your particular battery. Especially in our case where we most likely won't see a hardware fix from Tesla because they just keep blaming it on imbalances. I would really recommend it so you can see whats going on yourself.
I actually did rather out of necessity when we didn’t have any power for a few days this week. I “maxed” at the local super while I walked around a warm mall. It stopped at 96% and was charge complete. I tried unplugging and plugging back in and it wouldn’t start. I’ll see what service says on Monday and then look into scan my real.
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