Battery System (BP)
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| Authors |
|
| Responsible |
|
| Last Updated | 10/12/2025, 12:48:54 PM |
| Last Author | Kai Berszin |
Scope
This page describes the chosen battery solution for the SAGE CubeSat.
Quickfacts
| Manufacturer | GomSpace |
| Part Number | NanoPower BP4 |
| Configuration | 4 cells: 1P4S |
| Operating Voltage | 12 - 16.8V |
| Capacity | 3 Ah |
| Stored Energy | 43 Wh |
| Weigth | 258g |
| Size | 94 x 84 x 23 mm |
| Stack Connector | SSQ-126-02-G-D |
| Conformal coating | Not applied |
| Document freeze | DS 1013024 3.1 |
| Document freeze date | Sep 11, 2023 |
| Status | Delivered |
Block Diagram
The BP4 connects to the NanoPower P31u through a dedicated battery connector as well as through the stack
connector.
Pinout
H2 - Stack Connector
| Pin | Name | Dir. | Description |
|---|---|---|---|
| H2-29 | GND | O | Power Ground |
| H2-30 | GND | O | Power Ground |
| H2-32 | GND | O | Power Ground |
| H2-45 | V_BAT | O | Battery Voltage |
| H2-46 | V_BAT | O | Battery Voltage |
P1 - Battery Connector
The battery cells are connected to a 16-pin dual row 2 mm pitch female header. This connector fits with the female external battery connector of the GomSpace NanoPower P31 with a Samtec TW-08-07-G-D-375-188 in between.
| Pin | Name | Description |
|---|---|---|
| 1 | Vbat | Battery voltage connection |
| 2 | Vbat | Battery voltage connection |
| 3 | Vbat | Battery voltage connection |
| 4 | Vbat | Battery voltage connection |
| 5 | GND | Ground |
| 6 | GND | Ground |
| 7 | GND | Ground |
| 8 | GND | Ground |
| 9 | MISO | SPI MISO |
| 10 | MOSI | SPI MOSI |
| 11 | VCC | Supply voltage for temperature sensors |
| 12 | SCK | SPI SCK |
| 13 | CS1 | Chip select for temperature sensor 1 |
| 14 | CS2 | Chip select for temperature sensor 2 |
| 15 | PS | Active high power switch control (optional) |
| 16 | HS | Active high heater control |
P2 - Power-switch Output
Harwin M80-8670405
| Pin | Name | Description |
|---|---|---|
| 1 | Vout | Power Switch out |
| 2 | GND | Ground |
| 3 | Vout | Power Switch out |
| 4 | GND | Ground |
P3 - Ground-break Connector
Harwin M80-8670805
| Pin | Name | Description |
|---|---|---|
| 1 | GND | Ground |
| 2 | Bat GND | Battery negative terminal |
| 3 | GND | Ground |
| 4 | Bat GND | Battery negative terminal |
| 5 | GND | Ground |
| 6 | Bat GND | Battery negative terminal |
| 7 | GND | Ground |
| 8 | Bat GND | Battery negative terminal |
Heater
The heater is implemented as high side switches with drivers (with active high inputs) and are powered from the stack connector.
In the BP4, the heater is supplied from the VBAT channel in the stack. When used with a NanoPower P31u, this channel is always enabled.
Heater Characteristics
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Heater resistance | 82 | Ohm | ||
| Heater Power | 3.5 | 6 | 7 | Watt |
BP4 temp sensor Texas Instruments TMP121.
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Range | -40 | 128 | °C | |
| Accuracy | -2 | 1.5 | 2 | °C |
Power Switch
The power switch is implemented as high side switches with drivers (with active high inputs) and are powered from the stack connector.
Power switch characterisitics:
| Parameter | Condition | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|
| Control voltage | Active high | 1.5 | 6 | V | |
| Current | Continues | 1 | 3.9 | A |
Dimensions
All dimensions in mm.
