How CMΞC battery packs are made

Last update: 11-10-2018

CMEC UAV Battery

Technicality. 

Each part is separately made, then all the sub-assembly are joined together to engineering a battery pack. CMIUTA Electric Company uses original techniques in manufacturing to ensure maximum quality and performances.

6S battery pack NCR20700B
6S9P 135A NCR20700B                                  Panasonic NCR20700B 4.25Ah 15A

CMEC materials gif

Adding matching cells and to engineer the battery packs. To minimize the variability inside a battery pack and to ensure maximum quality, all the cells need to have the same weight (margins of 0.001 grams), identical voltage rated, same rank and initial charging date, from the same manufacturing batch.

Panasonic Sanyo NCR18650GA
Panasonic NCR18650GA 3.5Ah 10A

Thermal management.

An active cooling system based on air flux or liquid pipelines is more efficient but adds weight to the drone battery, that can reduce performances and operating time of this.
In the case of our battery pack, cell joining and a passive thermoregulation system described below is an optimal solution to keeps the weight of this as low as possible.

Between rows of cells, it inserted a thin thermally conductive strip, insulated and connected to the outer shell-layer reinforcement which contains aluminum layer. Its main purpose of the interstitial material it is to help absorbs and disperses /spreads heat accumulated in battery pack core, generated during high-discharge rate, prolong in this way the lifespan of the battery. This passive cooling technology relies on the thermodynamics of conduction.

CMEC UAV battery pack heatsink design
Thermally conductive interstitial layer inside battery packs. For a more compact design, translated into more energy density per unit volume and to improve mechanical and thermal performance, the battery cells are joined in “honeycomb form”.
CMEC ring-shaped dielectric material
The upper part of the cell is over-insulated with a ring-shaped dielectric material.

Using TECBOND, a hot-melt adhesive based on high-thermally conductive polyamide (PA) copolymer with great bond strength, the empty space between cells is filled and the battery pack is fully sealed.

6S6P-NCR18650GA-DRONE-BATTERY
6S6P 21Ah 60A NCR18650GA battery pack

Welding the cells.

The cells terminals are connected by layers of pure nickel busbar through RSW equipment, according to the battery configuration and C-rate (learn more about Resistance Spot Welding).

A non-toxic flame retardant encapsulating compound with high thermal conductivity and dielectric strength is used to seal the top and bottom of the cell block after the welding process.

Wiring, safety elements and covering.

Spending attention to detail and safety elements, the harnesses for PCB/BMS, polarized gold-plated connectors and shielded discharge cables are applied using Silver-Copper-tin alloy.

UAV Drone Battery

The entire cell block is surrounded by a multi-layers shield with mechanical strength and dielectric insulated, outside-reinforced with an aluminized film used in the spacecraft industry. All the covering materials are lightweight and provide a high sealing, improve thermal performance and contribute to the robustness of the battery pack.

To reduce manufacturing costs, the pack is wrapped with a hard (Black & Blue) PVC film. With this kind of covering the aesthetic appearance isn’t charming, but looks very compact and solid. However, we work hard to develop a tough and lightweight battery housing, from composite materials.

CMEC Lithium-Ion Battery Pack for UAVs


Upcoming in 2018

IBHS (Integrated Battery Heating System).

Because of the cold temperatures in high-altitude flight or polar climate applications, the UAV battery performance can be greatly reduced, we have found a technical solution to combat this issue by integrating a 20°C heating system, that is using a light and thin 6W element managed by a PTC thermistor. It is completely safe – has no direct contact with cells because this is achieved through the use (in the reverse) of interstitial strips for thermal transfer. The hardware requires 6V-20V power source connection from PDB/BEC of the aircraft.

 Ultimate manufacturability.

CMIUTA Electric Company will use 3D printing technology to manufacture a honeycomb-type battery cell holder from composite materials, for ultimate cooling efficiency, safeties and reliability. 8 hours it is average print time to mold a complete battery cell holder, including the covering parts

Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. Engineering Technologist: Cristian Miuta.


CMIUTA Electric Company it is a “blue” company

We care about global climate change and we like to be independents. The production facility is powered by 100% clean energy, generated by solar panels!

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