Start from the pack, not the catalog
Fix the series count and the nominal voltage first, then the worst-case continuous current the load will draw, then the surge behaviour. Only then does the model list narrow to a handful of codes.
- Series count, with the intended chemistry stated
- Continuous discharge current, taken from the inverter rating rather than the battery capacity
- Surge and inrush behaviour of the actual load
- Whether the pack needs Bluetooth, a wired display, or both
Headroom on the current rating
Sizing a board exactly to the inverter continuous rating leaves nothing for cable resistance, ambient temperature or the surge the inverter draws on startup. Leaving margin above the calculated continuous figure is the single most common correction made after a first order.
Ratings differ between model codes that look almost identical. Confirm the figures on the product page for the exact code before ordering.
Where BD stops being the right family
If the system needs inverter protocol communication rather than local monitoring, the PB family is the better starting point. If the pack is small and the balance requirement is high, look at B1A or B2A instead.
Official next steps
Frequently asked questions
Size above the inverter continuous rating rather than at it, so cable resistance, ambient heat and startup surge are covered.
Protocol support is model dependent. For protocol-led systems start from the PB family.
The family segment states it, for example JK-BD6A is 0.6A.