TBB Power BM-500 500A 12V / 24V / 48V Battery Shunt Monitor
- Measures battery current, voltage and state of charge for clearer control of solar, inverter and DC power systems.
- Rated for charge and discharge currents up to 500A, with support for 12V, 24V and 48V battery banks.
- Connects with compatible TBB monitoring displays through CAN or RS485 communication.
TBB Power BM-500 battery shunt
The TBB Power BM-500 is a 500A battery shunt for monitoring battery current and voltage in low-voltage DC systems. When used with a compatible TBB monitor or display, it provides live information including charge and discharge current, battery state of charge, remaining capacity, time to go and temperature.
The BM-500 supports a wide 7–95V battery-voltage range, making it suitable for 12V, 24V and 48V systems. It can be configured for AGM, GEL, wet lead-acid, traction, lead-carbon and Lithium Iron Phosphate (LiFePO4) batteries.
Key features
- 500A bidirectional monitoring: Measures charge and discharge current up to ±500A.
- Accurate system data: ±0.4% current accuracy and ±0.3% voltage accuracy.
- Multi-battery monitoring: Monitors the main auxiliary battery and the voltage of up to two starter batteries.
- Flexible integration: CAN and RS485 communication support for compatible TBB monitoring systems.
- Programmable dry contact: Normally-open, common and normally-closed terminals for external control or alarm functions.
Where to use
Use the TBB BM-500 in off-grid solar systems, campervans, motorhomes, boats, mobile work vehicles and backup-power installations where battery-bank information is needed. It is suitable for systems using TBB displays or compatible monitoring equipment.
Install the shunt close to the battery, with the main battery negative connected to the B− terminal and all DC loads and charge sources connected to the S− system side. This ensures all relevant current passes through the shunt for accurate state-of-charge calculation.
This is an indoor-rated DC component. Installation and maintenance should be carried out by a trained technician or qualified electrician. Energian UK expert support is available for battery-monitor selection and system design.
Technical specifications
| Model | BM500 |
| Product type | Battery shunt monitor |
| Communication | RS485, CAN |
| Nominal battery voltage | 7–95V DC |
| Suitable nominal systems | 12V, 24V and 48V DC battery systems |
| Nominal current | ±500A |
| Auxiliary battery voltage, +B1 | 7–95V DC |
| Starter-battery voltage, +V2 and +V3 | 1–95V DC; supports up to two starter batteries |
| Battery capacity range | 10–10,000Ah |
| Supported battery types | AGM, GEL, semi-traction, traction, lead-carbon and LFP |
| Temperature-sensor connection | 1 connection |
| Working temperature | -20°C to +50°C |
| Storage temperature | -30°C to +70°C |
| Voltage accuracy | ±0.3% |
| Current accuracy | ±0.4% |
| Dry-contact rating | 2A at 30V DC or 0.5A at 125V AC |
| DC terminals | B− battery negative; S− DC loads and starter-battery negative; +B1 auxiliary-battery positive; +V2 and +V3 starter-battery positive inputs |
| Status LED | Green flashing: normal operation; red flashing: error; solid red: auxiliary-battery charge or discharge current exceeds 500A |
| Dimensions, W × H × D | 105 × 105 × 63mm |
| Weight | 0.3kg |
| Ingress protection | IP20; indoor use only |
| Certification | CE certified; Safety: EN 60335-1:2012 and EN 62233:2008; EMC: EN 61000-6-3:2012 and EN 50498 Automotive EMC |
Documents available for download
Shipping
Available for shipping to the UK, Ireland, Africa, the Caribbean and worldwide. If the shipping rate is not shown at checkout, contact us on +44 2080 640335 or info@energian.co.uk for a quote.
UK expert support
UK expert support is available for battery monitoring, DC cable routing and TBB system integration. Contact us with any questions or support requests by phone, email or live chat, or visit our office for an in-person consultation.