Overview
The B04S003-L4S-5A is an active balancer in the Battery Accessories category, designed for 4S LiFePO4 / Li-ion battery packs. It supports 5A active balancing (energy transfer between adjacent cells) to help equalize cell voltage until balance is achieved. It is described as compatible with all JBD 4S Smart BMS.
Key Features
- Active balance current: 5A
- 4S support: for 4-series battery packs
- Energy-transfer balancing: voltage balance through energy transfer between adjacent battery cells; starts when cell voltage triggers active equalization and stops when balanced
- Claimed balancing accuracy: can be equalized to within 10 mV difference
- 24-hour balancing: described as 5A high current, 24-hour uninterrupted balance; stated as 5x the normal balanced current of 1A
- Hardware design notes: high quality capacitors; open heat dissipation design; reserved fixing screw positioning holes; snap-on cable interface designed to prevent reverse plugging and loosening
For product selection and wiring assistance, contact customer support at https://tsolar.top/ or service@tsolar.top.
Specifications
| Product name | Active Balancer |
| Type | Battery Accessories |
| Model number | B04S003-L4S-5A |
| Strings | 4S |
| Active balance current | 5A |
| Size | 70mm*56mm*21mm |
| PCB marking (as shown) | B04S003 V1.0; Size: 70*56mm |
Wiring Diagram & Terminals
- Balance terminals (labeled): B-, B1, B2, B3, B4
- Other labeled pins: VBN, GND
- Switch label: SW
Applications
- 4S lithium battery packs used in start power systems
- Portable power systems
- ESS battery systems
- Electric motorcycles
- Low-speed vehicles
- Sightseeing buses
Details
OEM/ODM supply and ready-to-ship inventory are available for battery management accessories.
Connect B-, B1–B4 in order to the 4-series pack for correct active balancing and polarity protection.
High-quality capacitors support stable energy-transfer balancing under continuous use.
An open PCB layout helps dissipate heat during 5A balancing.
Reserved mounting holes make it easier to secure the balancer inside a battery enclosure.
A snap-on connector reduces the risk of reverse plugging and loosening from vibration.
Designed for common 4S lithium pack applications, from portable power to light electric vehicles.
Active balancing transfers energy between adjacent cells when voltage differences trigger equalization.
Balancing helps bring cell voltages closer together for more consistent charging and discharging.
5A energy-transfer balancing is intended to reduce cell-to-cell differences and support long-term pack health.
Compliance and quality documentation may be available on request depending on the production batch.
Automated production and test equipment support consistent assembly for PCB modules.
Multiple payment options and standard export packaging support worldwide shipping.
