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Battery

Choosing carefully a battery

The technical specification of the battery results from a compromise between numerous factors, often antagonistic, notably: the battery technology, the voltage (U), the capacity (Ah). Equally, we have to take its use into account (cycles, emergency, traction...) and physical restraints such as weight, dimensions, temperature, etc.

TECSUP develops and manufactures custom lithium batteries.

The battery technologie

The choice of technology (lead open, lead sealed AGM, lead sealed Gel, Lithium polymer...) determines largely the weight, the performance of the battery and the cost. It characterizes:

  • The mass capacity (energy available for a given weight)
  • Performance in extreme temperatures
  • The length of its life (cycles: one cycle being one full charge followed by one full discharge).

The Voltage (U, called volt)

For a given battery technology, we will choose a voltage which could feed a maximum of equipment without having to go via a converter (less electronic guts, less electrical loss, cost and output optimization). When many batteries are interconnected, the voltage obtained from the pack is the sum of the voltage of the batteries cabled in series. Example: Two 12v batteries cabled in series gives a 24v battery pack.

The Capacity (Ah, called Amp hours)

It results from two factors:

  • The quantity of power needed to supply the equipment between two charges.
  • The maximum level of discharge (DOD = Depth of Discharge) that we can allow, important information which has a direct link with the length life (number of cycles) taken off of the battery.

The characterization of the length of life is functional to the DOD, which depends, itself on numerous factors: temperature, the rate of charge & discharge, etc, the most important of all is the battery technology itself.
Example: At identical uses, the Li-ion batteries the most sophisticated can offer around 2000 cycles of charge & discharge, an excellent quality battery will only give a few hundred cycles.

 

Lithium-ion battery

TECSUP masters the Lithium technology and uses it in many different solutions:
- Battery Management Systems
- Lithium battery chargers (constant current)
- Self-contained energy boxes
- Self-contained power cases

Advantages of Lithium batteries

  • High length of life: >1000 cycles
  • Reduced weight and volume
  • Better resistance to extreme temperatures
  • Reduced recharge time
  • Flexibility of uses

Guaranteed security

Amongst the many different Lithium technologies, the Lithium Iron Phosphate (LiFePo4) differentiates itself by its very high level of security (it doesn't burn).

Lead batteries

TECSUP masters the specificities of every lead battery typology: Lead open, Lead sealed (AGM, gel, spiraled).

"Open" Lead battery or "sealed" Lead battery?

The Open batteries contain an electro liquid, whereas in the sealed batteries, the electrolyte can be gelled or absorbed by micro porous material (AGM). In an AGM battery, the charge can move more freely between the plates, rather than in a Gel battery. That is why AGM is more adapted to supply high current for a short period than Gel batteries.
It is normal that at the end of a charge a sort of boiling occurs with open batteries. It is the oxygen and hydrogen that the battery gives off.

For the sealed batteries, the oxygen that forms on the positive plates shifts to the negative plates, where after a chemical reaction, combines itself again with the hydrogen and turns to water. We can call it re-composition of gas.

There should hardly be any gas emission from sealed batteries. If it does happen, then trouble shooting tells us that the charge curve or the voltage is too high.