- Correct LiFePO₄ cutoff thresholds: overcharge protection at 3.75 V, over-discharge protection at 2.1 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
- HY2112-BB protection IC – genuine 1S LiFePO₄ protection modules are hard to find on the market
- Any cell format: 18650, 21700, 26650, 32700 – 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 LiFePO₄ 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 HY2112-BB with the cutoff thresholds appropriate for LiFePO₄. 1S protection modules for LiFePO₄ are far rarer on the market than Li-ion modules – and virtually none of them 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 LiFePO4 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: HY2112-BB
- Overcharge protection: 3.75 V
- Over-discharge protection: 2.1 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: LiFePO₄, single cell (1S)
- Cell format: any – 18650, 21700, 26650, 32700 (soldered directly)
- Dimensions: 22 × 6.2 × 2.8 mm
What's in the box
- 1× battery protection module LiFePO₄ 1S with temperature sensor
⚠ Important notes
- For LiFePO₄ cells only. For Li-ion and LiPo, please use the corresponding Li-ion 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