A battery management system (BMS) is essential in a lithium ion battery build. Li-ion batteries are much more sensitive to voltage than lead acid, and can be dangerous if over- or under-charged. This BMS is for a 7S (25.9v nominal) lithium ion battery. It protects against over- and under-voltage as well as over-current, and ensures that the cells are balanced.
To wire, you will need to solder battery and charge/load ground to pads on the board. You will also need to tie each of the balance leads into the individual battery cells. You may notice that this only has 7 balance leads, whereas a typical 7S BMS has 8. This is because the last balance lead has been integrated into the BAT- on the board, saving you some time and effort. Note that this does NOT have provision for separate charge and load, as some boards do.
This BMS is suited for smaller projects, but don't expect it to be adequate to protect a large build such as an off-grid power wall. This is perfect for eBike and scooters up to 500 watts, as well as RC projects.
Specifications:
Battery type: 7-cell 3.7v nominal lithium ion battery. NOTE: Not suitable for LiFePO4 batteries
Balance current: 80mA at 4.20v
Overcharge cutoff: 4.3±.05v
Overcharge delay: 75 mS
Overcharge recovery: 4.1±.05v
Undercharge cutoff: 2.4±.08v
Undercharge delay: 5mS
Max continuous current: 20a
Max transient current: 30a
Power consumption: <500 uA
Protection type: load disconnect
7S Bms 24V 20A Panel Of Protection & Balancing Of Battery LI-ION 7 Cell
New: A brand-new, unused, unopened and undamaged item in original retail packaging (where packaging is applicable). If the item comes direct from a manufacturer, it may be delivered in non-retail packaging, such as a plain or unprinted box or plastic bag. See the seller's listing for full detail