From my understanding from watching YouTube videos of Tesla battery
teardowns is that a Tesla Model S uses 13 of these modules.That would total
$17875 using these and you would be missing all the plumbing and mounting
and such that comes with buying a Tesla battery pack on your own. Am I
correct here? Does anyone know of a source to buy complete Tesla takeout
Since most EVs wouldn't require an entire Tesla battery pack for their
builds separating them makes sense. Plus, most EVs don't have the physical
space available to use the entire Tesla battery pack.
How does this price compare to using other battery pack takeouts, say from
a Volt or a Leaf?
I'm still a long ways off from needing battery packs but want to know
what's available and reasonable costs and approaches when I am ready. Since
I am always on a tight budget I need to do all I can to keep purchases as
inexpensive as possible without incurring a significant amount of extra
Iirc in the 85kWh pack there are 16 modules, each module has 6 series connected groups of 74 cells in parallel, so full charge of one module is 6*4.2V = 25.2V, and capacity is about 240Ah. Most modules seem to go for around $1200 when sold by individuals, and they usually tell you the year and mileage of the vehicle they were taken from. Might be more cost effective to buy a wrecked Tesla S with low miles since there seem to be ample buyers for the drive train, the value of the glass, and scrape value of the aluminum body should be considerable, and you could sell the modules you don't use.
There are two difficulties with Tesla modules imo:
1) The larger the unit size the more difficult packing different battery box volumes becomes. These are quite large, module length with cooling tubes is 26.75", width is 11.8", generally resulting in inefficient use of volume.
2) The larger the voltage unit, the less flexibility in pack voltage due to limits of controller/motor max/min input voltage. Voltage of these is quite large, 25.2V full charge. So for example 7 modules in series
exceeds max voltage for the Curtis 144V AC controller with max 170V input since at full charge they would be 176.4V, although if you give 20 min or so after full charge for the cells to "relax" in voltage before closing the contactor to the controller it shouldn't be an issue, and much of the time you could just do a partial charge. Six modules do not make full use of the voltage range of the controller, limiting peak power. Higher voltage motors that require > 300V have a different problem in that they require many of these modules in series, making it difficult to fit enough modules in a converted vehicle to supply the required voltage.