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Discussion Starter #1
hi all!!

i found tesla battery perfect for my application, but i need much less modules but keep a 360\400volt..

so i found in the past somebody that did that.. i can't find anything now.. i forgot to save the page.

theoretically speaking... it could be possible to arrange just 4 modules so about 20kw to a configuration that rise the voltage at roughly 400v good for feed enough amps to a nissan leaf with a 200\300w of power?.. c rating would be enough for the amp required?

thank you all for any reply
 

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I haven't heard much about this company lately. If they are still around, they convert modules from 6s to 12s, ~25V to 50V :http://edisonmotors.net/shop/product/12s-converted-model-s-module-5-4-kwh-50-4-v-max-140

Please be careful using Tesla battery modules. Ask the people in this company about the dangers of not safely using these modules.

omg thanks!!! that is exactly what i was trying to find again. i will contach them... but i really didn't know about the safety of the tesla modules!! i mean as far as i knew those are the most safest... but your comment makes me think different.
 

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I haven't heard much about this company lately. If they are still around, they convert modules from 6s to 12s, ~25V to 50V :http://edisonmotors.net/shop/product/12s-converted-model-s-module-5-4-kwh-50-4-v-max-140


I'm not exactly sure what I'm looking at, but it looks like all they did was:

1 - Draw an outline around half the cells in a parallel set with blue sharpie. As in, if this pack had 40 cells, they drew a cut line between the first 20 and the next 20.

2 - Cut the bus plate with a dremel or zip cutter or depth-set router of some sort. So now it's physically 2 sets of 20 (not actual numbers).

3 - Drilled holes, probably added a protective insulator, and added a new bus plate to reconnect the formerly-single parallel pack into a set of 2 series packs half the size.

...

The "Engineering" for this is probably only the size of the bus plate, the insulator, and the method of attachment (looks like just screws).

Anyone who is careful could just as easily do this themselves with almost no tools.

...

Someone give that a once-over to confirm that I'm not crazy and that's all we're looking at.

i mean as far as i knew those are the most safest... but your comment makes me think different.
Safety isn't a Yes/No thing. You need to understand what is safe and or dangerous about them. Safe in the vehicle. Safe to handle or maintain. Safe over time. Etc. They're batteries. They're pretty well secured with glues and polycarbonate shields and apparently well engineered, but, no more so than anything inside a commercial vehicle. If you short them, at best case you will ruin them by blowing all their 26(?)g cell wiring that acts as fuses. Or worse, you'll zap yourself or burn down your whole house. Every battery is dangerous if you short it or throw it in a fire. If you can handle them without doing that, and without electrocuting yourself, they're pretty benign.
 

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I'm not exactly sure what I'm looking at, but it looks like all they did was:

1 - Draw an outline around half the cells in a parallel set with blue sharpie. As in, if this pack had 40 cells, they drew a cut line between the first 20 and the next 20.

2 - Cut the bus plate with a dremel or zip cutter or depth-set router of some sort. So now it's physically 2 sets of 20 (not actual numbers).

3 - Drilled holes, probably added a protective insulator, and added a new bus plate to reconnect the formerly-single parallel pack into a set of 2 series packs half the size.

...

The "Engineering" for this is probably only the size of the bus plate, the insulator, and the method of attachment (looks like just screws).

Anyone who is careful could just as easily do this themselves with almost no tools.

...

Someone give that a once-over to confirm that I'm not crazy and that's all we're looking at.
Yes, that's it.

There are, of course, some details...
  • The stock configuration is 6s, and the intermediate bus plates join the positive of one parallel set to the negative of the next, so if there were 40 cells per group then each plate would have 40 positive and 40 negative connections... and the cut needs to leave each of the two plates with 20 positive and 20 negative connections.
  • Both end plates and all five intermediate plates need to be cut.
  • Cutting plates and drilling holes (for the new connections) with mechanical tools would produce shavings, which couldn't be left floating around, so there would need to be a vacuum or similar system to gather all cuttings (during or after machining).
 

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There was forum discussion of this, in which a member did the conversion:
Tesla module 12s conversion - succesfull prototype!

Images from that thread converted to text links to work around forum problems:
Here's the post with a drawing showing the path of the cuts:
The image showing the cut path also shows the cells, with two sizes of circles indicating whether it is the positive or negative end of the cell. In this case, 74 cells per group (444 per module) were split into 37 cells per group; I believe that's the 85 kWh (with 14 modules) or 100 kWh (with 16 modules) battery pack.
 

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i found tesla battery perfect for my application, but i need much less modules but keep a 360\400volt..
...
theoretically speaking... it could be possible to arrange just 4 modules so about 20kw to a configuration that rise the voltage at roughly 400v good for feed enough amps to a nissan leaf with a 200\300w of power?.. c rating would be enough for the amp required?

thank you all for any reply
Since Tesla Model S/X modules are 6s, they are 22.5 volts nominally. To get close to 100 volts per module, you would need to split the cell groups in four, creating four strings of 6s, which you would then connect in series to make a 24s module. A 85 kWh or 100 kWh module has 444 cells per module, so 74 cells per group (6s74p). 74 isn't evenly divisible by 4, so you can't convert it to multiply the voltage by four (24s18.5p doesn't work). If there is a Tesla module with a number of cells per group which is a whole multiple of four (or a number of cells per modules which is a whole multiple of 24), then the quadruple-voltage conversion could possibly work.

... good for feed enough amps to a nissan leaf with a 200\300w of power?.. c rating would be enough for the amp required?
I have no idea what is intended by "200\300w of power".

If you double or quadruple the voltage, you are dividing the number of cells in parallel by two or four, so you have half or a quarter of the current capacity of the original.

Another way to think of this is that the maximum power output per cell or per module is unchanged by the reconfiguration. Four modules would be capable of providing one quarter of the total power of the full 16-module Tesla 100 kWh pack... if you maintain comparable cooling capacity and monitoring functionality.
 

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There was forum discussion of this, in which a member did the conversion:
Tesla module 12s conversion - succesfull prototype!

Here's the post with a drawing showing the path of the cuts:


The image showing the cut path also shows the cells, with two sizes of circles indicating whether it is the positive or negative end of the cell. In this case, 74 cells per group (444 per module) were split into 37 cells per group; I believe that's the 85 kWh (with 14 modules) or 100 kWh (with 16 modules) battery pack.
That is correct.

Hopefully all my posts with photo's will one day be restored by better forum software :( :(
 

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Discussion Starter #10
Since Tesla Model S/X modules are 6s, they are 22.5 volts nominally. To get close to 100 volts per module, you would need to split the cell groups in four, creating four strings of 6s, which you would then connect in series to make a 24s module. A 85 kWh or 100 kWh module has 444 cells per module, so 74 cells per group (6s74p). 74 isn't evenly divisible by 4, so you can't convert it to multiply the voltage by four (24s18.5p doesn't work). If there is a Tesla module with a number of cells per group which is a whole multiple of four (or a number of cells per modules which is a whole multiple of 24), then the quadruple-voltage conversion could possibly work.


I have no idea what is intended by "200\300w of power".

If you double or quadruple the voltage, you are dividing the number of cells in parallel by two or four, so you have half or a quarter of the current capacity of the original.

Another way to think of this is that the maximum power output per cell or per module is unchanged by the reconfiguration. Four modules would be capable of providing one quarter of the total power of the full 16-module Tesla 100 kWh pack... if you maintain comparable cooling capacity and monitoring functionality.

sorry for the delay on replying..

first of all thank you all for the various input on this topic... it looks like doable, so i can find some second hand packs and with the real things in my hand work on it to increase the voltage changeing the whole set up.

for the motor power i meant using a nissan leaf with an open controller to increase it's power to 200 to 300 depending on the reliability of such power..

my issue on reconfiguring the tesla battery is for the actual amperage that the pack can give that i guess with far less battery in parallel will be far less than a full 85kwh pack or like the smaller chevy volt pack that can give lots of amps...

the tesla 18650 as far as i found online it tollerate 3c discharge for small period of time... i'm just scared that this hypotetical set up of 4 rearranged modules can't give enough amps to the motor in a normal environment...
 

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for the motor power i meant using a nissan leaf with an open controller to increase it's power to 200 to 300 depending on the reliability of such power..
Ah... 200 to 300 kW, rather than the rated 80kW. One missing letter in a units symbol or one odd symbol ('\') can really confused a technical statement.

It appears that Nissan doesn't attempt to push the Leaf motor harder for brief periods (like Tesla's variously silly-named modes) either because the battery without active thermal management wouldn't be able to supply the required power, or due to inverter limitations. To me, that makes it reasonable to consider some degree of over-driving the Leaf motor, beyond Nissan's rating.

my issue on reconfiguring the tesla battery is for the actual amperage that the pack can give that i guess with far less battery in parallel will be far less than a full 85kwh pack or like the smaller chevy volt pack that can give lots of amps...

the tesla 18650 as far as i found online it tollerate 3c discharge for small period of time... i'm just scared that this hypotetical set up of 4 rearranged modules can't give enough amps to the motor in a normal environment...
Yes, the current versus voltage tradeoff is direct. That's one reason to think in terms of power. An EV's power output may be as limited by the battery as by the motor or controller. If you use one quarter of a Tesla pack, you can only reasonably expect to get one quarter of the peak power out that Tesla gets out of a full pack. Would that be over 200 kW? Can a Model S P100D get over 800 kW to the motors? :confused:
 

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Ah... 200 to 300 kW, rather than the rated 80kW. One missing letter in a units symbol or one odd symbol ('\') can really confused a technical statement.

It appears that Nissan doesn't attempt to push the Leaf motor harder for brief periods (like Tesla's variously silly-named modes) either because the battery without active thermal management wouldn't be able to supply the required power, or due to inverter limitations. To me, that makes it reasonable to consider some degree of over-driving the Leaf motor, beyond Nissan's rating.


Yes, the current versus voltage tradeoff is direct. That's one reason to think in terms of power. An EV's power output may be as limited by the battery as by the motor or controller. If you use one quarter of a Tesla pack, you can only reasonably expect to get one quarter of the peak power out that Tesla gets out of a full pack. Would that be over 200 kW? Can a Model S P100D get over 800 kW to the motors? :confused:

my knowledge is limited.. unfortunately.
thanks for this explanation, is very usefull to me.

the "teslonda" give enough amps under brief accelleration to a 400w tesla motor by just 14kw of a chevy battery.. so i thought 20kw from a rearranged tesla pack can give enough juice for a pumped up leaf engine... but i guess the chevy have something different....

give me your point of view on this if you want..
thanks!!!!!
 

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... the "teslonda" give enough amps under brief accelleration to a 400w tesla motor by just 14kw of a chevy battery..
That's presumably 400 kW (kilowatts) of power to the Tesla motor, and 14 kWh (kilowatt-hours) of Chevy battery capacity. I can guess that's what you meant, but if you don't take some care with the units it can be very confusing, or just unreadable.
 

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Discussion Starter #14
That's presumably 400 kW (kilowatts) of power to the Tesla motor, and 14 kWh (kilowatt-hours) of Chevy battery capacity. I can guess that's what you meant, but if you don't take some care with the units it can be very confusing, or just unreadable.
i'm so sorry!!!! i exactly meant what you write.... sorry
 
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