"24V BMS" describes two different packs in the mainstream chemistries, and the first specification decision is which one you are building. A 24V-class lithium pack is either 7S li-ion (NCM) — seven cells in series, 25.2V nominal — or 8S LiFePO4, eight cells at 25.6V nominal. The chemistry decides the cell count, and the cell count decides what the BMS must support. DALY's Smart BMS (A Series) covers both on the same low-range configuration: 8S sits at the top of the 4–8S LiFePO4 range, and 7S at the top of the 4–7S li-ion range, in current tiers from 40A to 400A.
Here is the cell-count match for both chemistries, followed by how one board covers them and how to set the current tier.
Cell Count Match at 24V
| 24V Build | Cells in Series | Nominal Voltage | Configuration Validation |
|---|---|---|---|
| LiFePO4 (LFP) | 8S | 25.6V | 4–8S LFP configuration ✓ — top of range |
| Li-ion (NCM) | 7S | 25.2V | 4–7S li-ion configuration ✓ — top of range |
Both cell counts land at the top of their configuration ranges, and both are standard product — no custom step at 8S LFP or 7S NCM. If a supplier has quoted either as a special build, note that both sit inside DALY's standard low-range configuration.
One Board, Both Chemistries
For a pack builder serving mixed 24V orders — LFP for solar and backup customers, NCM where energy density matters — the practical question is inventory. The A Series answers it with two functions on the same board.
Battery chemistry is switchable in the DALY app with one tap: the same physical board runs as an 8S LFP BMS this week and a 7S NCM BMS next week. And series count is detected automatically within 45 seconds of first power-on — no DIP switches, no per-unit configuration — so the board identifies whether it is sitting on 7 cells or 8 without being told.
The result is one stocked model for the entire 24V line, whichever chemistry each order specifies. All tiers carry dual UART, RS485, and CAN as standard interfaces, plus built-in Bluetooth for the DALY app.
Setting the Current Tier
The A Series covers 24V builds across four tiers:
| Current Tier | Continuous | Peak |
|---|---|---|
| 40A / 60A | 40A / 60A | 60A / 90A |
| 80A / 100A | 80A / 100A | 120A / 150A |
| 150A / 200A | 150A / 200A | 225A / 300A |
| 250A–400A | 250A / 300A / 400A | 375A–600A |
Two checks set the tier, whatever the application. Match the continuous rating to the load's measured sustained draw — mobility applications such as electric wheelchairs and scooters typically sit in the lower tiers, while industrial 24V loads such as AGVs (automated guided vehicles) reach higher, but measurement beats category assumptions. Then verify the peak column against the worst surge event the load produces; if surges approach a tier's peak ceiling, step up one tier.
For 24V energy storage banks, the built-in parallel module supports up to 10 packs in parallel with inrush protection between packs — the surge that flows when a new pack connects is limited rather than uncontrolled — so a 24V bank can grow after the first pack ships.
When Cell Consistency Is the Constraint
The A Series carries 100mA passive balancing as standard, which holds well-matched new cells in line in normal service. Where cell consistency is the limiting factor — large-capacity cells with wider spread, or second-life cells — the T Series active balancing BMS covers the same 4–8S LFP and 4–7S li-ion ranges with 1A bidirectional transformer balancing on the 40A–400A tiers.
Frequently Asked Questions
Q1Is a 24V BMS 7S or 8S?
Both exist, and chemistry decides: 8S for LiFePO4 (25.6V nominal), 7S for li-ion NCM (25.2V nominal). Specify the chemistry first; the cell count follows from it.
Q2Can one BMS board really serve both 7S NCM and 8S LFP orders?
Yes — chemistry is switchable in the DALY app, and the board detects the actual series count automatically within 45 seconds of first power-on. One stocked model covers the full 24V line across both chemistries.
Q3Which current tier does a 24V application need?
Set it from two measurements, not from the application category: the load's sustained draw sets the continuous tier, and the worst surge event must clear the tier's peak rating. If the surge approaches the peak ceiling, move up one tier.
About DALY
DALY designs and manufactures lithium battery management systems for pack manufacturers, OEMs, and integrators, with products used in 130+ countries. Founded in 2015, DALY provides pre-sale engineering confirmation and spec-matching support for production projects.
Requesting a Quote for a 24V Pack?
Cover the following in your inquiry — DALY's technical team replies with engineering confirmation for standard configurations within one business day.
- Chemistry and cell count (8S LiFePO4 / 7S NCM)
- Required continuous current, plus the worst surge event if defined
- Communication interfaces the application needs (UART / RS485 / CAN)
- Email: dalybms@dalyelec.com
Smart BMS category page: https://www.dalybms.com/smart-bms/
Post time: Jul-25-2026
