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Pack contents: 1 × BMS battery protection board in the selected model. Batteries, charger, wiring and motor are not included.
Choose a 3S or 4S lithium-ion battery protection board for your 18650 battery pack project. Six model options cover 3S 40A, 3S 60A and 4S 40A, each offered in Balance and Enhance versions.
Choose the correct model
3S is for three cell groups connected in series; 4S is for four cell groups. These boards are specified for lithium-ion cells with a nominal voltage of 3.7V and a fully charged voltage of 4.2V per cell. Match the series count, cell chemistry and load requirements before ordering.
| Model |
Pack full-charge voltage |
Maximum continuous discharge current* |
Maximum charge current* |
Approximate board size |
| 3S 40A Balance |
12.6V |
40A |
20A |
41 × 61 × 4mm |
| 3S 40A Enhance |
12.6V |
40A |
20A |
41 × 55 × 4mm |
| 3S 60A Balance |
12.6V |
60A |
15A |
41 × 62 × 3.4mm |
| 3S 60A Enhance |
12.6V |
60A |
15A |
41 × 55 × 3.4mm |
| 4S 40A Balance |
16.8V |
40A |
20A |
45 × 60 × 4mm |
| 4S 40A Enhance |
16.8V |
40A |
20A |
44 × 55 × 4mm |
*Current figures are the supplier's upper limits. Usable current depends on cooling, wiring and the battery cells' discharge capability; reduce the load if heat dissipation is inadequate.
Balance and Enhance versions
Select the Balance version when cell balancing is required. Enhance is the enhanced board option; the 3S 60A Enhance version does not include balanced charging. Refer to the selected model's product and wiring pictures before installation.
Installation and compatibility
This BMS is a protection board, not a complete standalone charger. Use a compatible lithium-ion charger for the selected series count. Follow the wiring diagram for the exact board and verify every connection before powering it. Use battery cells and conductors suitable for the required load, especially for motor starting current. High-current power connections require suitably sized copper wire; the source specifies at least 3mm² for 3S 40A and 4mm² for 3S 60A.
Delivery and support
Ships using our economy registered delivery service. Available destinations, charges and estimated delivery times are shown at checkout. Contact us before ordering if you need help confirming which listed model you require.
