Smart Active Balancer
NEEY-24S4A · also sold as EK-24S4EB · NEEY 4TH 4A Balancer
The entry point to app-controlled active balancing. 4 A of constant current through an onboard supercapacitor, ±1 mV cell acquisition, and a 140 × 128 mm board that fits most scooter and small-storage packs.
| Model | NEEY-24S4A (EK-24S4EB) |
|---|---|
| Cell count by chemistry | Li-ion 7S–24S · LiFePO4 8S–24S · LTO 12S–24S · sodium-ion 12S–24S |
| Cascading | Supported — see cascade wiring diagrams |
| Balance current | Adjustable in app: 1 A – 4 A |
| Balance method | Time-sharing single-channel, point-to-point energy transfer |
| Voltage accuracy | ±1 mV (battery powered) |
| Cell voltage range | 1.5 V – 4.5 V |
| Battery types | NCM (ternary) / LiFePO4 / LTO / sodium-ion |
| Power input | DC 25 V – 100 V, or battery powered |
| Undervoltage sleep | Adjustable in app: 1.5 V – 4.2 V |
| Communications | Bluetooth 5.x (Android / iOS / HarmonyOS) |
| TTL bus | Not available on this model |
| Protections | Mis-wiring protection, ribbon power-down detection, disorderly power-on detection |
| Fault alarm | Buzzer, configurable in app |
| Indicator LEDs | Blue = connected (blinking = not paired) · Green = balancing / balance complete · Red = internal fault or battery test failed |
| Power consumption | ≈1 W balancing, ≈0.5 W idle |
| Dimensions | L140 × W128 × T22 mm |
| Weight | 247 g (board) · 470 g (packed) |
| PCB / finish | FR-4, lead-free HASL |
| Operating temperature | -20 °C to +55 °C |
| Warranty | 1 year |
| Housing | Black ABS enclosure, printed front label, board inside |
| Idle / active draw | 10 mA idle · 25 mA balancing (at 100 V) |
| Recommended minimum pack | Li-ion ≥10S · LiFePO4 ≥12S · LTO ≥20S, or 30 V total |
Need a different connector, lead length or silkscreen? Custom configurations are standard — send us your pack details.
8 A NEEY-24S8A · 2S – 24S
Double the current of the 4A on almost the same footprint, and the first model in the range with a TTL port so the balancer can report to an external controller or charger.
10 A NEEY-24S10A · 2S – 24S
The 24S8A’s feature set at 10 A, in a slightly larger 166 × 157 mm board with heavier copper. Suited to 50 Ah–200 Ah traction and storage packs.
15 A NEEY-24S15A · 2S – 24S
The biggest balancer we build: 15 A of app-settable current, a 40S cascade example in the manual, and an over-balancing guard that halves the current automatically when the pack is already close to balanced.
Tell the finder your chemistry, cell count and pack capacity and it ranks every compatible model, with the ones that do not fit ruled out and explained. The selection guide compares all NEEY lines side by side instead.
