Home › Batteries › Tesla Model S/X

Tesla Model S/X Battery for Home Energy Storage

The Model S pack was the first mass-produced 400 V EV pack of the modern era. Now, more than a decade after the first S 60 packs entered service, a substantial pool of these batteries is entering the used market — ideal for large residential storage.

Battery generations

Variant	Capacity	Years	Cell format	Cell chemistry	Nominal V
Model S 60	60 kWh (usable ~55)	2012–2015	18650	Panasonic NCA	~355 V
Model S/X 75	75 kWh	2016–2020	18650	Panasonic NCA	~355 V
Model S/X 85 / P85	85 kWh	2012–2016	18650	Panasonic NCA	~355 V
Model S/X 90	90 kWh	2015–2017	18650	Panasonic NCA (Silicon-doped)	~355 V
Model S/X 100 / P100D	100 kWh	2016–2020	18650	Panasonic NCA	~355 V
Model S/X Plaid / Long Range	100+ kWh	2021+	2170	Panasonic NCA	~400 V

Cell technology

• 18650 legacy cells (2012–2020): Panasonic NCR18650 series, NCA chemistry. Nominal 3.6 V, capacity 3.1–3.4 Ah per cell depending on year. A Model S 85 pack contains 7104 cells.
• 2170 cells (2021+ Plaid / Long Range): larger Panasonic 2170 format (21 mm × 70 mm), higher energy density. NCA chemistry with newer separator and electrolyte formulation.
• All Tesla S/X cells are NCA — higher energy density than NMC but slightly more sensitive to over-temperature and overvoltage.

Pack topology

• Model S 85 (representative): 96 groups in series, each group is 74 cells in parallel (96s74p). Total 7104 cells.
• Model S 60/75: same 96s topology, fewer parallel cells (~44p for 60 kWh).
• Model S/X 100: 96s86p, ~8256 cells, taller module architecture.
• Plaid 100+ kWh: different physical module design using 2170 cells, still 96s but far fewer parallel cells per group.
• Operating voltage 250–420 V across the full SoC and load range.
• Pack weight: 540 kg (85), 625 kg (100), 620 kg (Plaid).

Cooling

All Tesla Model S/X packs use liquid cooling with a proprietary "ribbon" cooling channel snaking between every column of cells. Extremely thermally uniform under normal load. For residential reuse the coolant loop can remain passive at C-rates below 0.2 C, but for high-power backup or heavy cycling a 12 V circulation pump on the coolant loop is strongly recommended (Tesla's ribbon has narrow channels that benefit from active flow).

Original Tesla BMS

Tesla's BMS is an in-house design known as the BMB (Battery Management Board) at cell-group level plus the main BMS controller at pack level. Cell-group voltage and temperature are read via daisy-chained BMBs. The main BMS handles SoC, SoH, contactor sequencing, precharge, isolation resistance monitoring and cell balancing (passive, ~50 mA shunt). All safety cutoffs remain the exclusive responsibility of the factory BMS — the BMS-EV controller is a passive reader.

CAN protocol notes

• Tesla proprietary CAN. The same "Tesla family" protocol runs across Model S, X, 3 and Y but with different message IDs and payload layouts.
• Legacy S/X (60/75/85 kWh) CAN differs from later 90/100 kWh — message ID ranges shifted with a firmware generation change around 2016. Firmware variant at ordering must match the pack VIN.
• Bus speed 500 kbps classic CAN. Tesla vehicles have multiple CAN buses; the BMS-EV taps directly onto the HV-CAN inside the pack, bypassing the gateway.
• Wake-up sequence requires emulating the vehicle's front controller — the Tesla BMS expects periodic heartbeat frames or it opens contactors.
• Plaid (2021+) uses CAN-FD for some diagnostic streams but the BMS payload remains on classic CAN. The pack has additional 800 V-capable hardware features not currently used for stationary reuse.
• Contactor precharge is fully autonomous inside the pack — the BMS-EV only needs to signal "system ready" and the pack closes its own contactors in the correct sequence.

Compatible hybrid inverters

Inverter	DC input range	Compatible with	Notes
Deye SUN HP3	160–800 V	All S/X variants	BYD-Box or Pylontech-HV emulation
SOFAR HYD KTL-3PH	180–750 V	All S/X variants	SOFAR-HV protocol
GoodWe ET / EH	200–650 V	All S/X variants	GoodWe-native HV
SolaX X3 Hybrid G4 HV	180–650 V	All S/X variants	Triple MPPT
Sungrow SH-RT	200–800 V	All S/X variants	Native BYD support
Fronius GEN24 Plus	150–500 V	60/75/85 kWh legacy	BYD Battery-Box profile
SMA Sunny Tripower Storage	150–800 V	All S/X variants	SMA proprietary CAN

Known limitations

• Legacy 60/75/85 CAN differs from 90/100 CAN. Verify pack VIN before ordering firmware; the two are not interchangeable.
• Plaid 800 V hardware is NOT currently supported. The Plaid pack has 800 V-capable architecture (higher-voltage BMB topology) but we currently only support Plaid packs operated at their nominal ~400 V configuration. 800 V-mode integration is on the roadmap.
• 85 kWh packs with "P85" firmware (performance variant) have slightly different current calibration — flag at ordering.
• Model S 60 kWh (2012–2013 early builds) were physically 60 kWh packs but some were software-locked to 40 kWh — verify the pack is unlocked at 60 kWh before purchase.
• Coolant is proprietary Tesla G-48 equivalent — do not top off with generic glycol without checking compatibility.
• Pack removal requires specialised tooling — the underbody mounting scheme uses aluminium threadserts that strip if over-torqued.
• NCA chemistry is more thermally sensitive than NMC/LFP. Install in a fire-resistant enclosure with proper venting — this is standard practice but especially important for Tesla NCA.

Installation examples

• Model S 85 kWh + Deye SUN 12K-SG04LP3-EU HV — 15 kWp PV, full-home backup with EV charging, €5 200 total.
• Model S 100 kWh + Sungrow SH15T — 20 kWp PV, small business, €5 800 total.
• Model S 60 kWh + Fronius GEN24 Plus 10 — 8 kWp PV, residential, €4 100 total.

Order a Tesla Model S/X controller

Firmware pre-configured for your exact pack VIN and inverter

→

Frequently asked questions