this is gold, i love elder gentlemen with tons of technical knowledge and a slower speech, easy to understand, and they explain it so well, the Munro team is great, this channel is my new favorite informational tesla channel
I want to know who the reporter is that was talking at 6:04. Sounds like he's trying to get a direct quote from an expert to say something bad about Tesla's battery.
Keep in mind he said the battery would last 15 years before it drops below 70%. That means many batteries will still have about 50% charge after 30 years. Cybertruck will still have 200 mile range after 30 years and the truck will never rust. Ultimate farm equipment.
Don't forget, Tesla had already been making sure the batteries can, some day, be swapped easily. Specifically, you might be able to swap batteries faster than actually charging them
@@plainlybasic2300 Yes, until the issue of who owns the battery and would you be ok getting a bad battery installed? The legal problems of loaning out a $12k battery that you don't own and are only leasing as a service became unsellable to the public.
Are there different "bricks" in the SR+ battery? According to the ODB information the SR+ has the same voltage as the long range battery. So there should still be 96 bricks in series. But to only have 50kWh instead of 74kWh there should be ~31 cells in each SR+ brick as opposed to 46 cells in each long range battery brick. I assume that just using lesser bricks would result in a lower voltage.
It's gonna be Tesla's world, and everyone else is paying rent. Same as how every business paid Microsoft and IBM, and now Amazon web services, Tesla will license software and manufacturing technology to the existing and remaining oems
3:20 - the shorter modules have 23 bricks, the longer ones have 25 bricks (not 26). Only this way, it all adds up to 96 bricks. :-) M1 23s 46p 1058 cells M2 25s 46p 1150 cells M3 25s 46p 1150 cells M4 23s 46p 1058 cells total 96s 4416 cells, 79.488 Wh, assuming 5Ah per cell and 3.6V nominal voltage Tesla describes it as 75 kWh battery pack. 4:30 - You say, the "optional" battery pack has "three fewer groups of 46 cells in each of the four modules". This would translate to: M1: 20s 46p 920 cells M2: 22s 46p 1012 cells M3: 22s 46p 1012 cells M4: 20s 46p 920 cells total: 84s 3864 cells, a 69.552 Wh battery I do not believe you in that regard. That would translate to a 65 kWh battery pack, when named Tesla style. That is way too large for the standard range plus battery. Also the battery pack voltage would drop, which would be disadvantage when charging at current-limited DC chargers. Instead from other sources, the real organization is like this: Standard Range Plus Battery M1 23s 31p 713 cells M2 25s 31p 775 cells M3 25s 31p 775 cells M4 23s 31p 713 cells total 96s 2976 cells, 53.568 Wh Tesla describes it as 50 kWh battery pack. Source: electrek.co/2017/08/24/tesla-model-3-exclusive-battery-pack-architecture/ Instead of lowering overall voltage (84s), they keep the overall voltage (96s), so that for the e-motor and for charging, at least the voltage level remains the same, but currents going down. Mid Range Battery (available from January to March 2019) was right in the middle. The following is an educated guess and estimate: M1 23s 39p 897 cells M2 25s 39p 975 cells M3 25s 39p 975 cells M4 23s 39p 897 cells total 96s 3744 cells, 67.392 Wh Tesla could describe it as 63 kWh battery pack. Source: teslike.com/2018/10/19/estimated-range-and-battery-specs-for-tesla-model-3-mid-range/
Interested to hear how JB at Redwood materials will recycle this. It's obviously not designed for dis-assembly. They're probably planning to shred them and retrieve material mechanically and chemically? Sounds complex and expensive. Hope they've factored this in and review it at battery investor day. Super important for the planet and as a precedent as they scale up.
Anthony Smith I agree. The battery should last for a long time as it’s built for it. However, it contains a lot of glue and must be a nightmare to recycle ♻️
They glued it to make it watertight, and vibration/shock proof. Its better to design a product that is long lasting but more difficult to recycle, than an easy to recycle, but not long lasting product.
The nominal voltage of these Panasonic NCA cells is 3.6 V, not 3.5 like he says several times. 3.6 V * 96 = 345.6 V which is pretty close to the 350 V he mentioned at the nominal pack voltage.
All Chevy Bolts that have>ever< been produced are now in a massive recall. Until battery replacement, owners are not supposed to charge fully, deplete fully or park a Bolt inside, for fear of fire. Apparently, the Bolt has no ability to monitor the health of an individual cell in its complete battery pack. Otherwise, Chevy would be able to run a diagnostic to detect which Bolts have the issue. Kind of like a "check engine light" but for the battery itself. Here's my question: Is there any EV manufacturer that has this type of cell level monitoring in its battery pack? Tesla? VW? Anyone? I've driven a 2013 Nissan LEAF for 8 years, as I think about replacing it with a more modern and longer range EV, this is something I definitely would like to know before I buy.
so far that has been mentioned/planned just for one range type of shanghai giga model 3s, not for all model 3s, just fyi for anyone reading your question
He did not say the tiny "wires" were for vibration. He said they were fuses. He said the glue was necessary to prevent vibration from breaking the tiny "wires".
Actually the description now shows "Model 3 Battery" so it's likely an older video and not a Model Y. Maybe the title of this video in this relatively new channel will be edited for clarity at some point.
I heard that they have taken the aluminium wire bond process out and they'll be using laser welding to make the connection to the cell is the battery pack.
Why not have the a coating cover in side the battery cover like less the weight of the 96 wireing but have the cover electrolises plating like gold plating then have the pack with rubber seal less the glue more coverage then replace different packs when degraded or the pack not working optimal fix connectors to pack in manufacturing just gold plate inner cover try that Ford or Rivian
How much cells must have died to have -14% capacity on my SR+ model 3??? It has a lot imbalance when drive it on longer trips. Rated range is only 208-212 of the 240.. Tesla said ''it isn't -30% yet so it's as expected... as listed on website'' (I have the OBD ScanMyTesla tool, to read cell voltages and have automotive diploma’s and built DIY battery packs)
Munro Live Wow an answer! For us it has been lower useable capacity pretty much from the start. It never had the 240-mile rated range and it’s only half a year old. I visited service, tracked the capscity with apps, OBD-reading ScanMyTesla software, manually driving it empty and calculate it (after mitigating random factors by preheating hours from wall) In general all seems to work “ok” besides we seem to have started off with less useable capacity then the Model 3 SR (non-plus) version. My theory is that Tesla has a few packs that are not that great. The OBD-dongle ScanMyTesla says the total capacity including unuseable energy buffer is 46.x to 47.1kWh (it hovers abit between that) it rounds up to -13/14% at least. Note: car is from late 09-2019 and has 16.000km or 10k miles (but problem was there already at 500km or miles)
Not sure what you mean with reset. I have tried all the 90 to 5% and 100% to low SoC and then slow charge (albeit on 230v because EU). Latest test: 95.x% down to 5% (after hour long preheat and warmed battery, almost ideal weather) I was able to only use 40kWh. When pack got low. Imbalance increased to 64-78mv. ScanMyTesla, Teslafi and manual trip meter calculations all point to 44.3 kWh useable at absolute best starting from 100%, or 40kWh 90 to 0%
Each brick is 1s46p and the bricks are connected 96 bricks in series for a total battery of 96s46p (4416 cells) Each cell must be 350v/96s= 3.646v nominal/cell 75000 Wh (75kWh) / 350v = 214.3 Ah 214.3Ah / 46p = 4658 mAh/cell Spec shows 4800 mAh/cell (2170) Discovered this video: ua-cam.com/video/2nhQw7iGukE/v-deo.html
David McC 👍 I’d been reverse engineering the Porsche Taycan system (might as well do something while in covid lockdown 🤷🏻♂️) I’m a bit rusty on the ole calculations and thought I’d missed something 😎 thanks
I don't think it's simple glue. It probably has vibrating absolution ability. If you look at cell diagram, it's just a sheet of metal separated by thin insulator. If cell keep getting vibrate, those sheet of metal will probably rub into each other a lot result in damages and shorting.
Curt - Tesla made sure glue is NOT an Excelerant. and Tesla has a Blue Goo that Insulates the batteries and acts as Passive Coolant and works in cunjuction with the BMS.
Holy shit I can see this guy doe inside a little every time a reporter asked the same fucking question 7 times. When the one guy questioned the series vs parrallel wiring the poor guy looked a little homicidal 😂 God these aren't cars for (MOST) boomers. The guy tearing it apart and understanding it on the other hand,.. got mad respect for him. He is sharp as a fucking tack.
4:56 to see a grown man coughing in public is unsettling. So weird how these times make us feel that way for something so innocent. Saw someone shaking hands on a show last night and felt weird about it.
If you are going to make the battery pack a stressed structural part of the body (which would be really smart) then prismatic cells are better than those cylindrical cells because you can flatpack them which is stiffer.
Full of glue & not maintenance friendly? That's a bit pathetic. Other manufacturers have modules that can be easily dropped in/out if a cell is defective.
There should be a battery check every 3 to 6 months just like a oil change. Tesla needs to keep there batteries from catching fire to protect there customers.
1) Tesla’s catch fire 1/10th as frequently as gas cars and there have been no instances of model 3 spontaneous combustion. 2) The car performs diagnostics automatically on the battery pack all the time and will alert the driver if there is a potential concern.
i remember an early case where a Model S catched fire. the BMS noticed a problem with the Battery, and the car wanted to shedule a service appointment for that during the drive the issue happened, but the Car burned down before that. The issue turned out to be a Bullet stuck in the Battery Pack during the Drive in the end.
this is gold, i love elder gentlemen with tons of technical knowledge and a slower speech, easy to understand, and they explain it so well, the Munro team is great, this channel is my new favorite informational tesla channel
Then you should watch Jack Ricard. Do it at regular speed, I dare you...
This video is perfect listening it at 2x so I’m not bored to death.
This is from a Model 3 teardown in 2018. It's labeled as such on the website, but not here.
its a April Fool video from SANDY.
Boy, these guys are slow on the uptake when he says something. They must be reporters.
Correct! This footage was from a large group of reporters in our building in 2018 for the Model 3.
I want to know who the reporter is that was talking at 6:04. Sounds like he's trying to get a direct quote from an expert to say something bad about Tesla's battery.
komocode : Yes. “Gotcha Journalism”. . .
not everything's a conspiracy
See the look on that guys face when the guy mentioned the battery's longevity.
Keep in mind he said the battery would last 15 years before it drops below 70%. That means many batteries will still have about 50% charge after 30 years. Cybertruck will still have 200 mile range after 30 years and the truck will never rust. Ultimate farm equipment.
Time stamp for those who need it
ua-cam.com/video/64_iBKLSnGA/v-deo.html
Don't forget, Tesla had already been making sure the batteries can, some day, be swapped easily. Specifically, you might be able to swap batteries faster than actually charging them
I did read somewhere that Tesla wasn't making battery swapping a high priority anymore
@@plainlybasic2300 Yes, until the issue of who owns the battery and would you be ok getting a bad battery installed? The legal problems of loaning out a $12k battery that you don't own and are only leasing as a service became unsellable to the public.
I thoroughly enjoyed this. Another talent at Munro’s we want to see more on UA-cam!
15-20 years... Wow.
I think even that might end up being an underestimation.
@@TheAegisClaw looking forward to using my batteries after 15 years to island my house from the utility company. 👌
RIP Mark
Are there different "bricks" in the SR+ battery?
According to the ODB information the SR+ has the same voltage as the long range battery. So there should still be 96 bricks in series. But to only have 50kWh instead of 74kWh there should be ~31 cells in each SR+ brick as opposed to 46 cells in each long range battery brick.
I assume that just using lesser bricks would result in a lower voltage.
Preset: 1.25x - normal speed / 1.5x - Karpathy speed. You're welcome.
Thanks Mr. Mark Ellis. Great stuff and great knowledge!
Pay attention Einsteins, the video is from 2018.
And we thought that was advanced technology. They just announced batteries with 54% more range and -69% cost.
Game over to all other car companies.
It's gonna be Tesla's world, and everyone else is paying rent.
Same as how every business paid Microsoft and IBM, and now Amazon web services, Tesla will license software and manufacturing technology to the existing and remaining oems
Excellent video, thank you for posting that, I really enjoyed seeing some of the details in the Model 3 battery pack.
3:20 - the shorter modules have 23 bricks, the longer ones have 25 bricks (not 26). Only this way, it all adds up to 96 bricks. :-)
M1 23s 46p 1058 cells
M2 25s 46p 1150 cells
M3 25s 46p 1150 cells
M4 23s 46p 1058 cells
total 96s 4416 cells, 79.488
Wh, assuming 5Ah per cell and 3.6V nominal voltage
Tesla describes it as 75 kWh battery pack.
4:30 - You say, the "optional" battery pack has "three fewer groups of 46 cells in each of the four modules". This would translate to:
M1: 20s 46p 920
cells
M2: 22s 46p 1012
cells
M3: 22s 46p 1012
cells
M4: 20s 46p 920
cells
total: 84s 3864
cells, a 69.552 Wh battery
I do not believe you in that regard. That would translate to a 65 kWh battery pack, when named Tesla style. That is way too large for the standard range plus battery. Also the battery pack voltage would drop, which would be disadvantage when charging at current-limited DC chargers.
Instead from other sources, the real organization is like this:
Standard Range Plus Battery
M1 23s 31p 713
cells
M2 25s 31p 775
cells
M3 25s 31p 775
cells
M4 23s 31p 713
cells
total 96s 2976
cells, 53.568 Wh
Tesla describes it as 50 kWh battery pack.
Source: electrek.co/2017/08/24/tesla-model-3-exclusive-battery-pack-architecture/
Instead of lowering overall voltage (84s), they keep the overall voltage (96s), so that for the e-motor and for charging, at least the voltage level remains the same, but currents going down.
Mid Range Battery (available from January to March 2019) was right in the middle. The following is an educated guess and estimate:
M1 23s 39p 897
cells
M2 25s 39p 975
cells
M3 25s 39p 975
cells
M4 23s 39p 897
cells
total 96s 3744
cells, 67.392 Wh
Tesla could describe it as 63 kWh battery pack.
Source: teslike.com/2018/10/19/estimated-range-and-battery-specs-for-tesla-model-3-mid-range/
Interested to hear how JB at Redwood materials will recycle this. It's obviously not designed for dis-assembly. They're probably planning to shred them and retrieve material mechanically and chemically? Sounds complex and expensive. Hope they've factored this in and review it at battery investor day. Super important for the planet and as a precedent as they scale up.
Anthony Smith I agree. The battery should last for a long time as it’s built for it. However, it contains a lot of glue and must be a nightmare to recycle ♻️
@@TurreTuntematon
Unless they have some form of solvent to dissolve it?
They glued it to make it watertight, and vibration/shock proof. Its better to design a product that is long lasting but more difficult to recycle, than an easy to recycle, but not long lasting product.
@t c I dont know why you are talking about apple. It has nothing to do with the video.
Anthony - before Tesla batteries are Replaced , they can still be used in Consumer electronics and in Tesla Energy products.
That guys face when he said it last 15 to 20 years. 🤣
This guy reminds me of Slowpoke Rodriguez. But he dont need a gun because hes power is knowledge
With this kind of battery architecture, how are they able to balance individual cells?
They are not glued but siliconed to protect the packs hermetically. It's cheaper than using gaskets.
Love how he speaks!
You don't need to hammer and chisel open the battery pack. I heard from Rich a butter knife works just fine.
Lol
beautifull explanations and humoros presentation.
The nominal voltage of these Panasonic NCA cells is 3.6 V, not 3.5 like he says several times. 3.6 V * 96 = 345.6 V which is pretty close to the 350 V he mentioned at the nominal pack voltage.
What's the peak voltage at full charge? Around 4v? I know they're reserving some potential for longevity so they likely won't hit 4.2v.
All Chevy Bolts that have>ever< been produced are now in a massive recall. Until battery replacement, owners are not supposed to charge fully, deplete fully or park a Bolt inside, for fear of fire.
Apparently, the Bolt has no ability to monitor the health of an individual cell in its complete battery pack. Otherwise, Chevy would be able to run a diagnostic to detect which Bolts have the issue.
Kind of like a "check engine light" but for the battery itself.
Here's my question:
Is there any EV manufacturer that has this type of cell level monitoring in its battery pack? Tesla? VW? Anyone?
I've driven a 2013 Nissan LEAF for 8 years, as I think about replacing it with a more modern and longer range EV, this is something I definitely would like to know before I buy.
I would like to hear Mark's thoughts on the new battery ideas like going cell to pack and the possible switch to lithium iron phosphate batteries
I hope Sandy gets ahold of the TESLA Prismatic cells.
so far that has been mentioned/planned just for one range type of shanghai giga model 3s, not for all model 3s, just fyi for anyone reading your question
Those tiny wires to the cells are not for vibration! They are fuse wires to prevent thermal runaway!
He did not say the tiny "wires" were for vibration. He said they were fuses. He said the glue was necessary to prevent vibration from breaking the tiny "wires".
@@johnvolt9605 hearing impaired reading the words... my bad...can't read lips through the mask. :(
In your opinion is the battery pack any different than what the Model 3 uses? Any improvements anywhere?
Actually the description now shows "Model 3 Battery" so it's likely an older video and not a Model Y. Maybe the title of this video in this relatively new channel will be edited for clarity at some point.
I heard that they have taken the aluminium wire bond process out and they'll be using laser welding to make the connection to the cell is the battery pack.
awesome as usual!
Wow really interesting, thanks for sharing!
Has Panasonic has pulled out of battery making at Reno ?
no
Why not have the a coating cover in side the battery cover like less the weight of the 96 wireing but have the cover electrolises plating like gold plating then have the pack with rubber seal less the glue more coverage then replace different packs when degraded or the pack not working optimal fix connectors to pack in manufacturing just gold plate inner cover try that Ford or Rivian
96s46p battery pack 4416 cells and the spider wires are indeed fuses
How much cells must have died to have -14% capacity on my SR+ model 3??? It has a lot imbalance when drive it on longer trips. Rated range is only 208-212 of the 240.. Tesla said ''it isn't -30% yet so it's as expected... as listed on website''
(I have the OBD ScanMyTesla tool, to read cell voltages and have automotive diploma’s and built DIY battery packs)
I’ll ask Mark and get back to you. Thanks for your question.
That could largely be due to general degradation.
Munro Live Wow an answer! For us it has been lower useable capacity pretty much from the start. It never had the 240-mile rated range and it’s only half a year old. I visited service, tracked the capscity with apps, OBD-reading ScanMyTesla software, manually driving it empty and calculate it (after mitigating random factors by preheating hours from wall)
In general all seems to work “ok” besides we seem to have started off with less useable capacity then the Model 3 SR (non-plus) version.
My theory is that Tesla has a few packs that are not that great.
The OBD-dongle ScanMyTesla says the total capacity including unuseable energy buffer is 46.x to 47.1kWh (it hovers abit between that) it rounds up to -13/14% at least.
Note: car is from late 09-2019 and has 16.000km or 10k miles (but problem was there already at 500km or miles)
Reset your battery pack , RUN the battery down to 10% then slow charge to 100% with 120v.
Not sure what you mean with reset. I have tried all the 90 to 5% and 100% to low SoC and then slow charge (albeit on 230v because EU). Latest test: 95.x% down to 5% (after hour long preheat and warmed battery, almost ideal weather) I was able to only use 40kWh.
When pack got low. Imbalance increased to 64-78mv. ScanMyTesla, Teslafi and manual trip meter calculations all point to 44.3 kWh useable at absolute best starting from 100%, or 40kWh 90 to 0%
Each brick is 1s46p and the bricks are connected 96 bricks in series for a total battery of 96s46p (4416 cells)
Each cell must be 350v/96s= 3.646v nominal/cell
75000 Wh (75kWh) / 350v = 214.3 Ah
214.3Ah / 46p = 4658 mAh/cell
Spec shows 4800 mAh/cell (2170)
Discovered this video: ua-cam.com/video/2nhQw7iGukE/v-deo.html
Do you mind me asking where 96p came from in the second paragraph; 214.3Ah / 96p to = 2232mAh/cell
@@firstnamesecondname5341 Thanks, updated as I switched s with p
David McC 👍 I’d been reverse engineering the Porsche Taycan system (might as well do something while in covid lockdown 🤷🏻♂️) I’m a bit rusty on the ole calculations and thought I’d missed something 😎 thanks
really late reply but the real kwh is around 78/79
@@shitass3931 we can work it back... 4.8Ah * 46p * 350v = 77.28 kWh
Rest In Peace Mark. 😞
Automotive reporters are learning about EV batteries. 😄
Does the glue also work to suppress any fire?
Probably not directly I’d guess. but it prevents anything from vibrating or shifting which in turn reduces fire risk
I suspect they used some type of thermal suppression material within the brick to minimize heat propagation of a single cell thermal runaway.
I don't think it's simple glue. It probably has vibrating absolution ability. If you look at cell diagram, it's just a sheet of metal separated by thin insulator. If cell keep getting vibrate, those sheet of metal will probably rub into each other a lot result in damages and shorting.
ICE manufacturers should be required to build much heavier fuel tanks with better fire protection devices installed at the factory. ICE are dangerous.
Curt - Tesla made sure glue is NOT an Excelerant.
and Tesla has a Blue Goo that Insulates the batteries and acts as Passive Coolant and works in cunjuction with the BMS.
Holy shit I can see this guy doe inside a little every time a reporter asked the same fucking question 7 times. When the one guy questioned the series vs parrallel wiring the poor guy looked a little homicidal 😂 God these aren't cars for (MOST) boomers. The guy tearing it apart and understanding it on the other hand,.. got mad respect for him. He is sharp as a fucking tack.
Drink every time he says "battery pack"
4:56 to see a grown man coughing in public is unsettling. So weird how these times make us feel that way for something so innocent. Saw someone shaking hands on a show last night and felt weird about it.
Mr. Parker Im not a scared little chicken shit. If you are scared of your own shadow, stay home.
Dang, "Welcome to Battery Day." NCA Batteries, ~15 year lifetime.
Ya this is Model 3 yes?
Guy in front-left, not visible, was holding a sheet saying 'model 3 analysis', so, probably yes.
Yeah. But all of their packs are very similar
6:47 - 6:48 What are they saying?
Shot circuit protection is inside each cell..
Nope
03:04 unnecessary comment: there are 95 of these if its a 96s battery :D
You guys get tested.
You can hear from the voice that this guy has been smoking his whole life 😬
His skin too.
I met him over ten years ago and he sounded exactly the same even.
Open battery loose 11.4 km range.
Nickel Cobalt Aluminum.
96 x 3.7V = 355.2V
1 brick shorted results in a 2% loss of power.
"they call it a brick"
Did you have to be 70 and older to visit?
In other news senior engineers with companies willing to pay for them to attend, are senior. Who would have thought.
5:02 when this dude starts coughing...
WTF
Battery short loose voltage.
Someone just ask if Tesla makes their own cells😂
Kind of
Guy coughs at 5:00 no mask.
The video is from 2018.
If you are going to make the battery pack a stressed structural part of the body (which would be really smart) then prismatic cells are better than those cylindrical cells because you can flatpack them which is stiffer.
Cooling
@@samusaran7317 Ja,, da cooling
Full of glue & not maintenance friendly? That's a bit pathetic. Other manufacturers have modules that can be easily dropped in/out if a cell is defective.
When a guy started coughing I started being worried
Please don’t take stupid risks, wear a mask gloves and physical distances
Is that so hard?
This video was recorded in 2018
Oh look, another chicken shit, scared of his own shadow.
These man looks and sounds stoned
For shure this guys aint Engineers yiis.
This can’t be live? If it is yikes.
It is not.
No social distancing going on here, guy is coughing next to him. I wonder why the virus is spreading.
This is from 2018.
2 year old video
"OMG OMG VIRUS OMG" xD
No fact checking going on here, I wonder why misinformation is spreading.
SIX FEET SOCIAL DISTANCING! The guy on the left coughed! They can stand farther from each other. Made me nervous.
I assumed this is an old video.
This video was recorded almost two years ago
Made you nervous? Are you scared of your own shadow?
Stop the guy coughing. Where are the masks?
This video is from 2018
@@Darwinist when coughing was still just fine
There should be a battery check every 3 to 6 months just like a oil change. Tesla needs to keep there batteries from catching fire to protect there customers.
1) Tesla’s catch fire 1/10th as frequently as gas cars and there have been no instances of model 3 spontaneous combustion. 2) The car performs diagnostics automatically on the battery pack all the time and will alert the driver if there is a potential concern.
There ≠ Their
@@keco185 Tesla Shanghai is moving to LiFePO4 which is inherently even more safer than NCA. Fire prevention is going to be overkill.
i remember an early case where a Model S catched fire. the BMS noticed a problem with the Battery, and the car wanted to shedule a service appointment for that during the drive the issue happened, but the Car burned down before that. The issue turned out to be a Bullet stuck in the Battery Pack during the Drive in the end.
@@unitrader403Wait the bullet was stuck in the battery for some time, possibly days?