Ampster
Renewable Energy Hobbyist
The way I understand it Lithium is the broad category with LFP, Lipo and NMC as subsets. I supose you could add LTO to that as well.Correct. I'm lazy. I call everything not LFP, LiPo...
Tesla Battery charged to 28 volts, popping and shorted out
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nosys70
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the problem of doing this is it is misleading.
when you say lead battery, you know the a cell is 2V.
but when you say lithium, it just means there is some lithium in it and that is not very useful.
Li-ion id 3.7-4.25V, LifePo is 3.2-3.6, and other batteries with other form of lithium can have differents specs.
so just consider each lithium type as a class itself.
when you say lead battery, you know the a cell is 2V.
but when you say lithium, it just means there is some lithium in it and that is not very useful.
Li-ion id 3.7-4.25V, LifePo is 3.2-3.6, and other batteries with other form of lithium can have differents specs.
so just consider each lithium type as a class itself.
Ampster
Renewable Energy Hobbyist
I am using industry standard nomenclature. They all use Lithium Ions to transport the energy. That is the hierarchy defined by the industry. What you call Li-ion I think is misleading because it doesn't tell me much. And by the voltage you specified it most likely has Cobalt Nickel in it. Google it, look it up in Wikipedia or Battery University. But don't try to invent your own definition for a type of battery that has been around for 30 years.
nosys70
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no , what is misleading is saying you use lithium .
if you say you use Li-ion, everybody will know what you are talking about, the specs, the benefits and the risks.
if you use LFP , it is another beast with totally different parameters, so at that point we do not really care it use "lithium".
you say you use LFP or LiFePo4.
The same for other type of "lithium". (and except the Hype behind the lithium word , who really care about what is in the battery ?)
For some people if you say lithium they think about planes falling in flames from the sky or phones exploding in your pocket.
This thread is the proof in the pudding and the demonstration of it cost 1200$ to the original poster.
if you say you use Li-ion, everybody will know what you are talking about, the specs, the benefits and the risks.
if you use LFP , it is another beast with totally different parameters, so at that point we do not really care it use "lithium".
you say you use LFP or LiFePo4.
The same for other type of "lithium". (and except the Hype behind the lithium word , who really care about what is in the battery ?)
For some people if you say lithium they think about planes falling in flames from the sky or phones exploding in your pocket.
This thread is the proof in the pudding and the demonstration of it cost 1200$ to the original poster.
Ampster
Renewable Energy Hobbyist
Lithium-ion battery - Wikipedia
You are free to use any terms you want. Most people don't know the difference anyway. However before you give advice to charge a Lithium Ion battery to 4.2 volts be sure you understand the specific chemistry of that user.
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GXMnow
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I am an engineer and I research a ton before I do anything. Making changes to a lithium charger without knowing what the setting do, can be a big problem as we saw here. I would hope the charge controller has decent documentation so you can figure out what all the settings do. If you are messing with a few small cells and make a mistake, it could still pop a cell and maybe even catch fire, but when you have a cell bank that stores kilowatt hours and can dump hundreds of amps, you need to be very careful. We certainly don't want anyone getting hurt or burning down there house. So let's try to stress to anyone messing with battery banks that they must be very careful with any settings changes and try to keep us all safe.
In this case, not knowing the battery chemistry in use is not good, but the big problem here is that the Tesla packs are only 6S each.
They are the higher voltage type of cells that can charge to 4.2 volts, but with only 6 in series, that is a maximum pack voltage of only 25.2 volts. The "Lithium" setting in the charge controller may be for LFP or "Li Ion" which is a difference of 3.2 to 3.7 for the nominal voltage, but does it also have a selection for the number of cells? A "24 volt" LFP pack is typically 8 cells for 25.6 volts nominal, but the full charge voltage could still safely reach 29.2 volts. A "24 volt" Lithium with Cobalt cell is typically a 7 cell pack for a nominal voltage of 25.9 volts and a safe fully charged voltage of 29.4 volts. As you can see, those are both quite close, so I would not be shocked if the "Lithium" setting on the charge controller uses a full charge of about 29 volts, and a low voltage cutoff of about 22 volts which would be safe for both types. But I would still read the manual and make sure of the voltages before trying it. The pack also does need to have some sort of BMS to protect the cells, and the people and property around them. Without a BMS, the cells can go out of balance far enough, that one group is going too low on discharge and another is going too high on charge, even though the whole pack voltage is well in the safe range.
It seems odd that most of the larger EV packs are not using the "normal" amount of cells. The Tesla with just 6S, the Chevy Bolt with 10S and 8S, and Mercedes and BMW using 16S. I wonder if they are actually doing this to discourage using the packs straight out of a car? Most of the cars end up with a total of 96S. That give a full charge just over 400 volts. That does work out to 12 x 8S packs, or 16 x 6S packs. But by using the Chevy logic, they could mix sizes. Too bad the Chevy Bolt is not 6 x 14S and a 12S. The Nissan Leaf cells work out pretty good with each module being just a 2S. You can do any even number of cells, so 14S for a 48 volts works, but doing 24 volts is a problem.
In this case, not knowing the battery chemistry in use is not good, but the big problem here is that the Tesla packs are only 6S each.
They are the higher voltage type of cells that can charge to 4.2 volts, but with only 6 in series, that is a maximum pack voltage of only 25.2 volts. The "Lithium" setting in the charge controller may be for LFP or "Li Ion" which is a difference of 3.2 to 3.7 for the nominal voltage, but does it also have a selection for the number of cells? A "24 volt" LFP pack is typically 8 cells for 25.6 volts nominal, but the full charge voltage could still safely reach 29.2 volts. A "24 volt" Lithium with Cobalt cell is typically a 7 cell pack for a nominal voltage of 25.9 volts and a safe fully charged voltage of 29.4 volts. As you can see, those are both quite close, so I would not be shocked if the "Lithium" setting on the charge controller uses a full charge of about 29 volts, and a low voltage cutoff of about 22 volts which would be safe for both types. But I would still read the manual and make sure of the voltages before trying it. The pack also does need to have some sort of BMS to protect the cells, and the people and property around them. Without a BMS, the cells can go out of balance far enough, that one group is going too low on discharge and another is going too high on charge, even though the whole pack voltage is well in the safe range.
It seems odd that most of the larger EV packs are not using the "normal" amount of cells. The Tesla with just 6S, the Chevy Bolt with 10S and 8S, and Mercedes and BMW using 16S. I wonder if they are actually doing this to discourage using the packs straight out of a car? Most of the cars end up with a total of 96S. That give a full charge just over 400 volts. That does work out to 12 x 8S packs, or 16 x 6S packs. But by using the Chevy logic, they could mix sizes. Too bad the Chevy Bolt is not 6 x 14S and a 12S. The Nissan Leaf cells work out pretty good with each module being just a 2S. You can do any even number of cells, so 14S for a 48 volts works, but doing 24 volts is a problem.
Ampster
Renewable Energy Hobbyist
I would imagine the EV manufacturers have their own logic which seems normal to them since their packs are 300 volts or more. In the case of Tesla even they have evolved because the Model 3 modules are probably 100 volts and five or six feet long. I don't even know what "normal" amount of cells would consist of? In Tesla's case they are using small cylindrical cells and most of the others are using prismatic pouches in their own modules.
I have heard reports that for cost reasons Tesla may be evolving to a single pack with no modules.
No doubt all of this will effect the market for used EV batteries. I for one have just retired my used Nissan Leaf modules in favor of new LFP cells. There is still a market for Leaf Modules because they are easily configurable in to packs of 24 and 48 volts. I had my leaf modules configured as 12S but many people using that chemistry go with 14S On the other hand my LFP cells will probably be 16S. I was thinking of 17S if my cabinet could fit that many cells, My inverter can handle voltages from 42 to 60 volts. YMMV
Sorry i didnt read all your answers but yes u ruined your battery the tesla module is 6s 74p 444 cells its top voltage is 4.2 per 18650 cell x 6 25.2 volts over that you damaged the cells you were at almost 4.7 per cell
SG-1
New Member
I have been doing a lot of research on this, for my own setup. The upper voltage on the tesla module you were using is way to much. I can't remember exactly where I saw it, or the exact figure but the voltages I can remember is never charge above 25.2v preferabley lower 21v to upper 25v. The charge controller you had was set more on the conservative side but by upping the voltage to those settings have definetly doomed your pack.
Ampster
Renewable Energy Hobbyist
We haven't heard from the OP since this occurred so I hope everything turned out okay. I also did a lot of research on Tesla modules be cause I drive two of them. I eventually decided on using LFP packs because of the incremental ease of expansion and putting them in parallel.
SG-1
New Member
You can do the same with Tesla's, just make sure you have active BMS installed to make sure they are always balanced and you never overcharge them. Big thing with tesla's if your only drawing 250amp max from a battery pack there is little chance of damage from heat normally. Adding extra tesla batterys does mean you can up your amps and run 2x inverters easily.
Battleborn or other electric vehicles in th USA are more numerous. Not so much in Australia ATM, so need to use what we have here.
I have even looked at using Prius or Camry Hybrid Batterys as an alternative with multiple active BMS to run an RV setup. That still beats lead acid every day of the week.
Ampster
Renewable Energy Hobbyist
So there is a good supply of Tesla modules down under?
SG-1
New Member
true on the last point, though building an expandable system is more benifical than getting stuck with one that can't be expanded easily
SG-1
New Member
2000 each + shipping.
2x packs inc shipping $4300
SG-1
New Member
2x 5.2kWh Tesla Battery Packs. running with a Victron 24v Multiplus with Ve Bluetooth Dongel. BMS is not bluetooth, so looking at getting Daly BMS to monitor SOC and active balance. All items can be easily expanded on, including to 3 phase if I choose (Expandable to 6x inverters on each phase).
SG-1
New Member
they came from a writen off tesla that had done 23,000km. Exact location I am keeping to myself for now, because I am planning on buying more from the same place soon. If you go looking you will find them.
SG-1
New Member
weigh that up with no power bills, you can see the method clearly
when you weigh it up over no power bills, it becomes very clear indeed
I hear you, ROI paralysis, just get what works for you and have some redundancy, if one dies you can keep going till it is replaced.
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