A lithium battery pack is only as dependable as the cells, connections, protection system and workmanship inside it.
At Michigan Lithium Packs, we design and hand-build BMS-protected lithium battery packs in Howell, Michigan. Our process begins with quality cells from established manufacturers and continues through careful assembly, electrical inspection and final testing.
Capacity printed on a wrapper does not tell the whole story. Internal resistance, discharge capability, temperature behavior, consistency and manufacturer data all matter when selecting cells for a finished battery pack.
The Samsung 50E is a strong option for energy-focused packs where long runtime and efficient packaging are more important than extreme per-cell current.
Samsung lists 4,900mAh standard capacity in its cell specification.
The NCR18650GA provides an excellent balance of capacity, compact dimensions and moderate-current performance for range-oriented lithium battery packs.
Finished-pack energy density is lower after adding conductors, insulation, BMS, connectors and enclosure materials.
The Murata VTC6 is useful when a design requires a better balance between useful capacity and higher current capability, such as performance mobility or other demanding loads.
Actual current limits depend on pack configuration, temperature control, enclosure and duty cycle.
Cell availability and manufacturer specifications may change. We select cells according to the pack's voltage, current, runtime, size, thermal and lifecycle requirements—not simply by choosing the cell with the largest advertised capacity.
High-energy cylindrical cells make it possible to store substantial energy in compact battery packs. That can mean longer e-bike range, greater equipment runtime or reduced pack size compared with older battery technologies.
Cell-level energy density is not the same as finished-pack energy density. A safe and usable pack also needs cell holders or insulation, bus material, wiring, connectors, protective electronics, mechanical reinforcement and an enclosure.
Our objective is not to chase a single laboratory number. It is to create the best combination of energy, power, durability, temperature performance and protection for the actual application.
No single cell or chemistry leads every category. Good battery engineering is about selecting the right tradeoffs.
Voltage alone does not determine the best battery. Available space, expected current, cycle frequency, charging time, weight, temperature and service life all influence chemistry selection.
Energy-oriented lithium-ion chemistries are well suited to applications where size, weight and runtime are major design priorities.
Lithium iron phosphate is frequently selected when cycle life, thermal stability and repeated daily use are more important than maximum possible energy density.
LTO is useful in specialized applications that prioritize high power, rapid charging, temperature performance and very durable cycling over compact energy storage.
Cycle life depends on depth of discharge, charge voltage, current, temperature, storage state, cell design and application conditions. Chemistry names alone do not guarantee a specific number of cycles.
We begin with required voltage, capacity, continuous and peak current, dimensions, connectors, charger, environment and expected duty cycle.
We choose a cell and chemistry that provide the appropriate balance of runtime, current, size, weight, temperature performance and cycle durability.
Series groups establish battery voltage while parallel groups increase capacity and current capability. The configuration is calculated around the intended load.
Cells are arranged, insulated and connected according to the design, with attention given to current paths, spacing, strain relief and protection against unintended contact.
The battery management system is selected for the cell count, chemistry, charging method, expected current and required temperature or communication features.
The finished battery is inspected and tested before approval. It must pass the checks defined for its design before it is prepared for delivery.
A BMS monitors critical electrical conditions and can disconnect charging or discharging when configured limits are exceeded.
The correct BMS depends on chemistry, series count, current, charger, temperature range and load behavior. A small e-bike battery and a large stationary storage pack do not necessarily require the same protection hardware.
BMS protection is one layer in a complete battery system. Proper charging, connectors, wiring, insulation, fusing, enclosure and application-level design remain important.
Helps stop charging when a monitored cell group reaches the configured upper-voltage limit.
Helps disconnect the load before a cell group falls below the configured lower-voltage limit.
Responds when charging or discharging current exceeds the BMS protection threshold.
Provides rapid electronic protection against certain output short-circuit conditions.
Sensor-equipped systems can limit charging or discharging outside the configured temperature range.
Helps reduce voltage differences between series groups during the charging process.
Testing is not an afterthought. It is the final step that verifies the completed battery behaves as expected before it is approved for delivery.
We inspect the pack for damaged insulation, exposed conductive material, loose connections, incorrect routing and enclosure issues.
Output polarity, connector configuration and open-circuit voltage are checked before the pack is approved.
Series-group voltages are examined to identify abnormal imbalance or assembly problems.
Charging behavior and applicable BMS functions are verified against the pack design.
The pack is evaluated under an appropriate electrical load while voltage behavior, connections and temperature are observed.
The completed pack is passed only after the applicable inspection and test checks have been completed.
We enjoy solving battery challenges across many different industries and personal projects.
Both are cylindrical lithium-ion cell formats. A 21700 cell is physically larger and can often store more energy per cell, while 18650 cells remain useful where packaging, availability or specific power characteristics make them a better fit.
There is no single best chemistry. NMC and NCA are useful for compact, high-energy packs. LiFePO4 is frequently selected for long-cycle storage and repeated use. LTO can be appropriate for specialized high-power and high-cycle applications.
Our protected battery designs use a BMS selected for the chemistry, voltage, cell count, current and application. Available functions may include overcharge, over-discharge, over-current, short-circuit, temperature and balancing protection.
We can review custom e-bike and electric mobility battery requirements, including voltage, capacity, current, dimensions, enclosure, connector and charger compatibility. Not every enclosure or legacy system can be safely reproduced, so each request is reviewed individually.
The test plan depends on the pack, but may include visual inspection, voltage and polarity checks, cell-group review, charging verification, BMS operation, load testing and thermal observation.
Tell Kyle and Gage about your voltage, runtime, current, size and connector requirements. We will review the project and help identify the right next step.
