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I've not seen this addressed and I've often wondered about it so I'll throw it out there. Does a lithium battery pack really need a BMS or do just the larger modules EV's use with the plastic housing?
Apparently the Tesla doesn't have a BMS in the sense of monitoring each battery as most home built EV's do. I've wondered for a while whether a BMS is really needed if you have it set up properly.
The Tesla uses 6800 of the Panasonic 18650 battery at 2.9ah. The pack is comprised of 11 modules, each with it's own microprocessor sending voltage and temp reading to the cars main processor. Each module apparently has about 618 cells. Below is link to a summary of the battery packs configuration and it's properties.
The batteries, unlike typical EV batteries use internal pressure relief mechanism and a passive over current protection mechanism built in and is contained in a steel canister to help dissipate heat which also extends the cell life. Also the pack is assembled with two fuses, one on each terminal which disconnects the cell in the event of a short somewhere external to the cell.
Seems there is a lot of fault protection measures not used in typical plastic housed models.
http://www.google.com/url?sa=t&sour...OnBBi0YUQ&sig2=J4FdtkbBiVAHHoyYSp2JLA&cad=rja
Apparently the Tesla doesn't have a BMS in the sense of monitoring each battery as most home built EV's do. I've wondered for a while whether a BMS is really needed if you have it set up properly.
The Tesla uses 6800 of the Panasonic 18650 battery at 2.9ah. The pack is comprised of 11 modules, each with it's own microprocessor sending voltage and temp reading to the cars main processor. Each module apparently has about 618 cells. Below is link to a summary of the battery packs configuration and it's properties.
The batteries, unlike typical EV batteries use internal pressure relief mechanism and a passive over current protection mechanism built in and is contained in a steel canister to help dissipate heat which also extends the cell life. Also the pack is assembled with two fuses, one on each terminal which disconnects the cell in the event of a short somewhere external to the cell.
Seems there is a lot of fault protection measures not used in typical plastic housed models.
http://www.google.com/url?sa=t&sour...OnBBi0YUQ&sig2=J4FdtkbBiVAHHoyYSp2JLA&cad=rja