43.2V 10.5Ah 12S3P 18650 Battery Pack with UN38.3 Certified

43.2V 10.5Ah 12S3P 18650 Battery Pack with UN38.3 Certified

This 43.2V 10.5Ah 18650 battery pack — built as a 12S3P lithium ion battery and also specified by customers simply as a 43.2V 10.5Ah lithium battery — was developed for a manufacturer of portable backup power systems. Their requirement had stalled two previous suppliers: deliver 43.2V at 10.5Ah inside an 86 × 188 × 70 mm footprint, with a pack that could survive repeated handling and transport vibration in the field, seal out dust and light moisture, and clear customs without delay on every shipment.

Based on these requirements, CMB’s engineering team developed the CMB12030146 — a custom 43.2V 10.5Ah 18650 battery pack configured 12S3P — built around energy-optimized 18650 cells selected and capacity/impedance-matched for consistent performance across all three parallel groups, a BMS with active cell balancing, epoxy-plate construction rated to IP54, and a mechanical package engineered specifically to pass vibration testing.

Portable Backup Power Customer Overview

The customer’s backup units are carried, mounted, and redeployed across field sites rather than sitting in a fixed installation. That duty cycle makes mechanical durability during transport and handling, consistent runtime across the pack’s service life, and a compact form factor that fits an existing enclosure the three factors that determine whether the product survives real-world use.

Vibration Damages Cells and Loosens Connectors in the Field

Portable packs that rely on standard cell holders and off-the-shelf connectors are prone to cell shift and connector wear under repeated transport vibration, leading to intermittent contact and premature field failures.

CMB Solution:
Internal cell brackets lock each 18650 cell in position, epoxy plates stabilize the full assembly, and a custom-designed connector — selected specifically for retention under mechanical stress — replaces the standard connector used in the customer’s earlier packs. This 18650 battery pack was engineered to pass vibration testing before release.

Parallel-Cell Imbalance Shortens Runtime and Cycle Life

In any 3P group, a single cell with lower capacity or higher internal resistance drags the whole group’s usable capacity down to its own level, and that mismatch compounds over hundreds of cycles.

CMB Solution:
Cells are capacity- and impedance-matched at incoming inspection before assembly, and the BMS performs active balancing across all 12 series positions — keeping the three parallel groups working together rather than letting the weakest cell set the pack’s effective runtime.

Standard Battery Modules Don’t Fit Compact Enclosures

Off-the-shelf 12S packs are typically sized around generic enclosures, forcing OEMs to redesign their housing or oversize the unit just to accommodate the battery.

CMB Solution:
This 43.2V 10.5Ah lithium ion battery was engineered to a fixed 86 × 188 × 70 mm target from the outset, delivering the full 10.5Ah inside the customer’s existing enclosure with no mechanical redesign required on their side.

Dust and Moisture Ingress in Field Deployment

Portable equipment moved between indoor storage and outdoor or workshop environments is regularly exposed to dust and incidental splashing, a common failure point for unsealed battery packs.

CMB Solution:
Epoxy plate construction seals the pack’s exposed seams and connector interface to an IP54 rating, protecting against dust ingress and splashing water while keeping the assembly serviceable and within the target weight.

43.2V 10.5Ah Lithium Ion 18650 Battery Pack Design

Product Highlights

  • Configuration: 12S3P — 36 total 18650 cells, energy-optimized lithium-ion chemistry, capacity- and impedance-matched (~3.5Ah per cell)
  • Nominal voltage / capacity: 43.2V / 10.5Ah @0.2C — the defining spec of this 18650 battery pack
  • BMS: Comprehensive protection (over-charge, over-discharge, over-current, short-circuit) with active cell balancing
  • Mechanical stabilization: Engineered cell brackets, epoxy plate construction, custom high-retention connector — vibration-tested design
  • Ingress protection:  IP54 (epoxy plate construction)
  • Dimensions: 86 × 188 × 70 mm
  • Certification: UN38.3 — View / Download Certificate ←
  • Application: Portable backup power systems
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43.2V 10.5Ah Lithium 18650 Battery Pack Parameters

No. Item Parameter Remark
1 Nominal Voltage 43.62V 3.635V/Cell
2 Nominal Capacity 10.5Ah @0.2C
3 Minimum Capacity 10.2Ah
4 Shipment Voltage /
5 Initial Internal Impedance ≤170mΩ AC 1KHZ
6 Standard Charge Voltage 50.4V 4.2V/Cell
7 Standard Charge Current 2.1A @0.2C
8 Max. Charge Current 5A
9 Standard Discharge Current 2.1A @0.2C
10 Max. Discharge Current 30A
11 Burst Discharge Curren 100±10A ≤1200ms
12 Discharge Cut-off Voltage 30V 2.5V/Cell
13 Cycle Life ≥350cycles Retention: ≥70%
14 Charge Temperature 0°C~+45°C Standard Charge
15 Discharge Temperature -20°C ~+60°C Standard Discharge
16 Storage Temperature -20°C~ +45°C ≤3 Months
-20°C~ +25°C ≤1 Year
17 Weight About 2.15 kg
18 Special Request Label must display: 62400-00024-R

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43.2V 10.5Ah 18650 Battery Pack FAQs

Is a 43.2V 10.5Ah 18650 battery pack the same as a 43.2V 10.5Ah lithium-ion battery?

Yes, with a clarification of terms. “18650” describes the cylindrical cell format used inside the pack, while “lithium-ion” describes the cell chemistry. CMB12030146 is a 43.2V 10.5Ah lithium-ion battery built from 18650-format cells in a 12S3P configuration — so 18650 battery pack, lithium-ion battery, and lithium battery all correctly describe the same product.

Why does a 12S3P 18650 battery pack need active cell balancing?

In a 12S3P architecture, three cells sit in parallel at each of the 12 series positions. If a parallel group drifts in capacity or resistance relative to the others, the pack’s usable runtime and cycle life fall to that group’s level. CMB12030146’s BMS actively balances across all 12 positions, and cells are capacity/impedance-matched before assembly so the groups stay in step over the pack’s service life.

How is IP54 protection achieved on this 43.2V 10.5Ah lithium battery without a fully potted enclosure?

Epoxy plate construction seals the pack’s exposed seams and connector interface against dust ingress and splashing water, achieving IP54 while keeping the assembly serviceable and within the target weight and footprint.

Is this 43.2V 10.5Ah 18650 battery pack built to survive vibration during transport and field use?

Yes. CMB12030146 uses internal cell brackets to prevent cell shift, epoxy plates to stabilize the assembly, and a custom-designed connector selected for retention under mechanical stress, rather than a standard off-the-shelf connector. The pack was engineered specifically to pass vibration testing before release.

Is the 43.2V 10.5Ah lithium-ion battery safe to ship internationally?

CMB12030146 is UN38.3 certified, meeting the UN Manual of Tests and Criteria required for international transport of lithium batteries by air, sea, and road.

Can the 12S3P configuration be resized for a different voltage or runtime?

Yes. Series count (S) sets nominal voltage and parallel count (P) sets capacity, so CMB can rework the configuration, cell selection, and enclosure footprint to hit a different voltage or runtime target for the same portable backup application.

Tailored Customization

Our design team can create custom battery designs for just about any device or machine.

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