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BMS Configuration for alternative cell counts (i.e. Tesla Modules)

This PDF describes how to modify an Overkill Solar BMS for alternative cell counts.

Overkill Solar normally stocks 3 basic BMS models, which are configured for the most common Lithium Iron Phosphate (LiFePO4) battery setups: 4 cell 12v nominal, 8 cell 24v nominal, and 16 cell 48v nominal.

When using a different cell chemistry such as classic lithium ion, the number of cells needs to be adjusted to reach a usable system voltage. Common setups are 6 or 7 cells for a 24v system, and 12 or 13 cells for a 48v system.

Download the PDF instructions to read on: BMS_configuration_for_other_cell_counts-4S_and_8S-Overkill_Solar_LLC.pdf

Adapting an 8s BMS for 6s Tesla modules

Our Tesla BMS kits include a 8s BMS which has been preprogrammed with the parameters for 6 cell Tesla modules, and the included adapter board makes the necessary connections to make the BMS work with 6 cells. If you already have a BMS in the 8 cell configuration, you can adapt it for 6 cells by shorting 2 pairs of the balance wires together as shown in the above PDF, and in the photo below:

After making these connections, you can load the configuration file “6s_Tesla_Li-ion” from the Overkill Solar mobile app.

2 thoughts on “BMS Configuration for alternative cell counts (i.e. Tesla Modules)

  1. Hi , do you have the wiring shematic for 2 tesla modules 24v in series with your BMS for 48v?
    Is it 2 6S BMS or you could do one 12S BMS?
    Thanks

    1. We don’t stock a 12 cell BMS yet. It is on the to-do list.

      To connect two 6s batteries in series, connect the black C- wire from the high-side battery to the B+ terminal on the low-side battery. (2 complete 6s batteries with BMSs connected in series)

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