Model S Modules

The Module Itself:


Each module consists of six “cells” of nominal 3.6vdc consisting of 74 Panasonic NCA 18650 cylindrical battery cells of approximately 3.2Ah capacity in parallel. This 6S74P configuration then features a nominal voltage of 21.6v at 233 Ampere-hours for 5032 Watt-hour capacity.


Length 27 in / 685mm

Total width with mounting fins 11 13/16 in / 300mm

Height 3 in / 75mm

Terminals  9 in / 230mm

Tubing 5/16 in / 8mm

Weight: 56.5lbs / 25.6kg



The cells should never be charged above 4.2v nor discharged under 2.8v. A Model S draws as much as 1200A briefly upon acceleration. However, the fuse is 450A and this is a more reasonable figure for long term current production. In the car, these modules are liquid cooled. Usually people using these modules for off-grid use will not use liquid cooling. However, usually people have more than 2 modules as well. A 20 module configuration would be 10 sets of 2 modules. Two modules in series is around 44V and each module is safely about 220AH so 10 of them in parallel is 2200AH of 44V. Such a system could provide 10kw of power with each module only needing to provide about 21A. This is low enough to be very comfortable without any liquid cooling. However, attempting to draw 10kw from 2 modules would not be advisable without cooling. In general, if you have at least 6 modules, you should be fine having a 10kw system without needing any cooling.


Slave Board On Module:

Each module has a “slave” board on it which can communicate with a “master” board in order for all modules to be able to be monitored and balanced. Our V2 system acts as the master board for up to 20 modules.

There are two types of slave boards. You can change out a bad board for a different one without any consequences but you must use the proper board type. Below are pictures of the two types of slave boards you will find:

Newer Style Boards (Front / Back)

Older Style Boards (Front / Back)

Note that each board type has different connectors compared to the other when it comes to connecting to the battery pack. For this reason, you cannot easily swap from one style to the other. It is HIGHLY recommended to stay with the type of board that originally came with each module.

For both board types, there is an LED on the front of the board. This LED will light for nearly one second upon power up and then flash during communication with the master side. If this LED never lights then suspect that either the board is not getting any power or it has gone bad.

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