NEEY · Active Battery Balancing & BMS
Bluetooth-enabled active balancers for 2S–24S lithium packs. A supercapacitor inside the balancer is charged by the strongest cell and discharged into the weakest one, repeatedly, until the pack is within your target delta-voltage. Time-sharing single-channel transfer — point-to-point energy transfer through an onboard supercapacitor.
Model finder
Chemistry, cells in series and pack capacity are enough. We rank the boards that actually fit, explain why the others do not, and show the price — no enquiry required.
Flagship
Bluetooth-controlled supercapacitor balancers for 2S–24S packs. Pick your amperage — every model shares the same app, the same protection suite and the same cascade wiring.
4 A NEEY-24S4A · 2S – 24S
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.
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.
Most capable 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.
Why active balancing
Passive balancers burn the strongest cell’s energy as heat, at tens of milliamps. A NEEY active balancer moves that energy instead — from the full cell to the empty one — at amps, so a large pack actually reaches balance before the next charge cycle.
The highest-voltage cell charges an onboard supercapacitor. Nothing is dissipated; the energy is held, not burned.
The capacitor — or a matrix transformer on our inductive boards — discharges straight into the weakest cell, point to point.
Set target delta-voltage, balance current and sleep thresholds from the app, and watch every cell voltage live over Bluetooth.
Cell taps connected, Bluetooth paired, current set — the balancer starts on its own and stops when the pack is inside your threshold.
Installation & troubleshootingEverything we build
From a 4-gram inductive board for a 2S pack to a 600 A sealed contactor for a 1000 Vdc storage cabinet.
Supercapacitor energy transfer, controlled from your phone
4 A NEEY-24S4A · 2S – 24S
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.
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.
Every cell balances at the same time
5.5 A EK-C3S5A · 3S
Whole-pack simultaneous balancing for 3S packs, no external supply and no configuration. 45 g on the board.
5.5 A EK-C4S5A · 3S – 4S
Whole-pack simultaneous balancing for 3S–4S packs, no external supply and no configuration. 55 g on the board.
5.5 A EK-C5S5A · 4S – 5S
Whole-pack simultaneous balancing for 4S–5S packs, no external supply and no configuration. 70 g on the board.
5.5 A EK-C6S5A · 4S – 6S
Whole-pack simultaneous balancing for 4S–5S–6S packs, no external supply and no configuration. 85 g on the board.
The lightest way to stop cell drift
2 A DG-2S 2A · 2S
Adjacent-cell inductive balancing for 2S packs. 4 g, ten microamps at rest, and no external supply — the cheapest way to keep a pack from drifting.
2 A DG-3S 2A · 3S
Adjacent-cell inductive balancing for 3S packs. 7 g, ten microamps at rest, and no external supply — the cheapest way to keep a pack from drifting.
2 A DG-4S 2A · 4S
Adjacent-cell inductive balancing for 4S packs. 10 g, ten microamps at rest, and no external supply — the cheapest way to keep a pack from drifting.
2 A DG-5S 2A · 5S
Adjacent-cell inductive balancing for 5S packs. 12 g, ten microamps at rest, and no external supply — the cheapest way to keep a pack from drifting.
Stand-alone balancing for whole packs, off the battery
5 A NY-FD04AS24G · 2S – 24S
The simplest of the bench range: a fixed 5 A resistive discharge balancer for 2S–24S packs. Wire every tap to the terminal strip, start it, and it brings the strings down to match without any current to set.
1 – 7 A NY-FD24SCG-7 · 2S – 24S
Same discharge-only topology as the FD04AS24G but with a 1–7 A adjustable balance current, so you can match the discharge rate to how much capacity has to come off the pack.
0.1 – 14 A NY-FD14AS24CK · 2S – 24S
The highest-current instrument in the range at 14 A, and the only one that can balance upward: a PWM pulse discharge path plus a charge-balancing mode that tops the weak cells back up. Needs an external charger that can be adjusted and stopped automatically.
0.1 – 7 A NY-FD07AS24CK · 2S – 24S
The three-mode CK instrument at 7 A. Same discharge, constant-voltage and charge balancing as the FD14AS24CK, for shops that do not need the extra current headroom.
Sealed contacts for 1000Vdc battery systems
EV100 · —
A compact 100 A DC contactor rated 12–1000 Vdc with up to 125 kW switching capacity. Epoxy sealed, non-polar coil, mounts in any position.
EV500 · —
250 A switching with 500 A long-term carrying at 85 °C, a built-in coil economizer and optional auxiliary contacts for main-loop monitoring.
EV600 · —
Our highest-current contactor: 600 A switching at 12–1000 Vdc, ceramic arc-extinguishing chamber, and 2500 A overload disconnection.
Protection boards with built-in balancing
30 A NEEY 7S 30 A · 7S
7S protection board for Li-ion and LiFePO4 packs with built-in balancing and low internal resistance MOSFETs.
30 A NEEY 10S 30 A · 10S
10S protection board for Li-ion and LiFePO4 packs with built-in balancing and low internal resistance MOSFETs.
50 A NEEY 16S 50 A · 16S
16S protection board for Li-ion and LiFePO4 packs with built-in balancing and low internal resistance MOSFETs.
50 A NEEY 17S 50 A · 17S
17S protection board for Li-ion and LiFePO4 packs with built-in balancing and low internal resistance MOSFETs.
Adapters, extension cables and booster modules
NEEY 4A Adapter · —
Break-out adapter board for the 4A balancer, for packs whose tap spacing does not match the default connector.
NEEY-Adapter15A · —
Break-out adapter board for the 15A balancer’s 7.62 mm screw terminals.
NEEY 4A Extra Cable · —
Extra-length cell sampling leads for the 4A balancer when the pack taps sit further from the board than the standard set reaches.
Custom cell counts, connector layouts, silkscreen and firmware branding are standard work for us. Our factory ships to installers and distributors in more than 130 countries, with EU, US and Brazil warehousing for faster delivery.
Chemistry, cell count, capacity and how much time you have — we will specify the right balancer and current.
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