TESLA BATTERIES

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rtgunner

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Jan 14, 2018
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I got impatient testing my cells (only half way through 200 18650's so far) so I decided to test out the
Tesla batts.

I like them so far...

image_gaegud.jpg
 
Well, they are just hangin around. Might as well test them :p
 
Cool. So what's the voltage and capacity of that rig?
 
Wattsup said:
Cool. So what's the voltage and capacity of that rig?
Click to expand...

Here are the specs as I have them:
22p15s 3kWh each
Voltage nominal: 3.8V/Cell, 57.0V/Module
Charge voltage cut-off: 4.2V/Cell, 63.0V/Module
Discharging cut-off: 3.3V/Cell, 50V/Module
Maximum Discharging Current (10 sec.):150 Amps


These modules are also wired for BMS already, although I imagine some modifications and tweaking would be needed to adapt
to say Batrium or similar BMS system.
Just got them on line yesterday. Very stable voltage under light load. Going to see how well
they perform under heavy load once I put a few more charge cycles in them. Glad I switched to 48v batts.
 
Im pretty sure they are 15s22p though :p

Yeah 48V rocks!
 
Is it 22 strings in parallel of 15 in series or 15packs in serie of 22 cells? :) Im pretty sure its the later because otherwise a pain in the ass to hook up BMS since it would need 22 BMS systems...
 
daromer said:
Is it 22 strings in parallel of 15 in series or 15packs in serie of 22 cells? :) Im pretty sure its the later because otherwise a pain in the ass to hook up BMS since it would need 22 BMS systems...
Click to expand...

I pretty sure it is 22p15s. not sure how tesla hooks BMS to these batteries. It has an ATx connector for all the thermistors and BMS... I have yet to dig into the pinout and system that Tesla uses...

I also think it it 22p15s by the way it has been charging... 15p I would see higher temp on charge...
 
3.8 x 15 = 57volts, which is the nominal in your specs.
 
rtgunner: Look at the letter combination and not the numbers. Its generally s before p. The difference is how its hooked up internally and I still think it is
15s22p and not 22p15s... The later you got 22 parallel single strings => 22 BMS systems needed meanwhile the first requires 1. Same voltage and same total capacity...
 
As the following depicts two different naming schemes.

4s3p vs 3p4s.
The 3p4s would need 3 bms' because the cells can't balance with each other in parallel.

image_nphsmx.jpg


They both have the same voltage, amperage, and capacity capabilities. But the wiring is different for the two. Electrically they are identical on the ends. Physically they are different and require more monitoring hardware.
 
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