Batteries specs – Reality or myth ?

There are many lithium batteries on the market. Many of them try to impress the gallery with colorful specifications. The problem is that these technical specifications on paper rarely represent the reality.

The question is whether the product presented is serious and trustworthy.

Here are the 3 main criteria to consider when evaluating quality:

1. Quality of lithium cells
2. Quality of electronic components
3. Assembly engineering

LFP cells: Lithium iron phosphate

All new lithium batteries will provide a capacity as stated on the package. However, Volthium is distinguished by a capacity always higher than what is displayed by about 10%.

Moreover, the quality of the cells inside a lithium battery is recognized when they have the following characteristics

1. Type or model, suitable for use :

There are different types of cells, and each one has advantages and disadvantages, depending on the environment of use (PouchCell vs Cylindic vs Prismatic)

1. The prismatic is, by design, adapted to all facets of our Canadian environment:
   1. High conductivity & large welding surface
   2. Excellent performance against charging and discharging intensity
   3. Vibration resistance
   4. Resistance to temperature variations
   5. Substantially higher cycle count and wear life
   6. Prismatic, high-end category: The manufacturer of the cell must have an unquestionable reputation. This is mainly what will ensure safety and long life for the consumer.
      Volthium deals exclusively with cell manufacturers who are specialized in the automotive industry. The manufacturers, whose cells are intended for the automotive industry are considered to be the safest and most durable.
   7. Purchasing channel: Brand name cells can be found on the alternative market (Gray Market). These cells should be avoided, as they are the rejects, coming from suppliers who could not sell them to their customers directly. So these cells are resold in batches, on alibaba or sold to other sellers who can sell them to their customers, often hobbyists.
   8. Our cells are certified to UL1973, UL1642, UL9540A, IEC62619, AND IEC62660, which are internationally recognized quality standards.

• Perfect match and homogeneity:

It is essential that the battery is composed of matched cells.

1. Provides a guarantee that the battery will perform equally and consistently over the years.
   1. After 300 complete cycles, unmatched cells will show capacity loss problems during charging and discharging.
   2. Ensures that the paralleled batteries remain balanced over the cycles.
   3. Ensures even aging of the battery.

Quality of electronic components

The internal BMS plays a major role in the safety and efficiency of the battery. Several criteria will define the quality of the BMS:

• Quality of the Mosfet : These are strongly solicited at the time of the load and the discharge, they will accumulate much heat and thus must be of great quality to be able to support temperatures beyond 100 degrees for periods of peaks (30sec to 15 min).
• Coating layer on printed circuit components. At Volthium, 5 layers of polymer cover the printed circuit boards to protect the components from temperature variations and corrosion in case of air leakage.
• Microcontrollers: Texas Instrument provides the processors and microcontrollers on the BMS. If NASA and the U.S. Army trust Texas Instrument, we think we can trust them too.
• Temperature sensor: 2 temperature sensors are located inside the battery for equal temperature control.
• Programming and rules: The quality of the programming and algorithms has a lot to do with the reliability of the battery. Indeed, the management of temperature, protections against overload / undervoltage, protection against short circuits, and the automation of the balancing of the cells contribute to the reliability of the battery.
• Product Control: The batteries are conceptualized, designed, tested and programmed here, this ensures that Volthium has absolute control over the battery’s behavior.

Internal engineering

Assembly is a direct result of the quality of engineering and will be profitable in the medium and long term.

At Volthium, we find :

• Cells are welded and fused to the pure aluminum busbars. The busbars are also chemically treated to avoid oxidation.
  • The competition commonly uses recycled aluminum busbars. These will eventually oxidize, and they will no longer conduct electricity.
• 100% optimized dimensions. Volthium offers the 100AH in group 24, and the 300AH in 8D.  The competition offers larger battery sizes for less amperage.
• Bolts that are not welded have a locTite additive.
• The internal wire size is always larger than the required standard
• Custom molds enclose the cells to allow air to circulate between them (improves temperature control during discharge).
• Anti-shock dampers to counteract vibration
• Heating device for cold temperatures. Some batteries have a double self-heating system (manual + automatic).
• Creation of a custom-made housing with free access to the electronics.
  • Exclusivity so that in the event of a breakage on a battery, it will not be necessary to change the whole bank of batteries (in parallel, or in series). Only the defective part will be changed in case of misfortune.
  • Higher operating temperature range: By isolating the BMS in a chamber, heat contamination from the BMS to the cells is limited, thus extending the battery’s allowable operating range.
    • (Think of a boat slipway with a diesel engine in the middle of summer).