- Protects 1S Li-ion and LiPo cells: overcharge protection at 4.275 V, over-discharge protection at 2.8 V, short-circuit protection
- Usually just called a BMS in the mesh community – technically a 1S protection circuit (PCM)
- Integrated temperature sensor – supplies the MR2 with the cell temperature for temperature-controlled charging
- BQ29700 protection IC from Texas Instruments instead of the usual DW01A
- Any cell format: 18650, 21700, 26650, pouch/LiPo – the module is soldered directly to the cell
- Compact: 22 × 6.2 × 2.8 mm, 1 A continuous current
- Also available pre-assembled – in the battery cable for the MR2 with protection module
Description
Battery protection module for single-cell Li-ion batteries (1S) with an integrated temperature sensor – protects the cell against overcharge, over-discharge and short circuit while supplying the Inhero MR2 with the cell temperature for charge control.
The module is based on the BQ29700 from Texas Instruments. Off-the-shelf 1S protection modules mostly use the simpler DW01A and do not include a temperature sensor matched to the MR2.
On the name: BMS or protection module?
In the MeshCore and Meshtastic communities a module like this is almost always called a BMS – if you are searching for a “1S Li-ion BMS”, this is the part you mean. Strictly speaking a Battery Management System does more than this: cell balancing, charge control, thermal management, communication. This module is a pure protection circuit (PCM) for a single cell. Balancing is irrelevant at 1S anyway, and on the MR2 charge control is handled by the onboard BQ25798. Functionally it does exactly the job the community means when it says BMS.
Technical specifications
- Protection IC: BQ29700 (Texas Instruments)
- Overcharge protection: 4.275 V
- Over-discharge protection: 2.8 V
- Short-circuit protection: yes
- Continuous current: 1 A max. (charge and discharge)
- Cell balancing: no (not required at 1S)
- Temperature sensor: integrated, matched to the Inhero MR2
- Cell chemistry: Li-ion / LiPo, single cell (1S)
- Cell format: any – 18650, 21700, 26650, pouch (soldered directly)
- Dimensions: 22 × 6.2 × 2.8 mm
What's in the box
- 1× battery protection module Li-ion 1S with temperature sensor
⚠ Important notes
- For Li-ion / LiPo cells only. For LiFePO₄, please use the corresponding LiFePO₄ version – the cutoff thresholds are not compatible and mixing them up will damage the cell.
-
Limit the charge current: the MR2 charge current is adjustable up to 1500 mA via the CLI. When using this module, cap it at 1000 mA (
set board.imax 1000). - The module is soldered to the cell. If you would rather avoid soldering at the cell, it is available pre-assembled in the battery cable for the MR2 with protection module.
- ESD-sensitive assembly – handle only with appropriate ESD protection.
- Battery not included.
Manufacturer Information (GPSR)
Inhero GmbH, Gewerbestraße 19, 08115 Lichtentanne, Germany · info@inhero.de