1. Cell Selection

Every Radenite battery is assembled using new cells. Your Radenite battery will never contain any recycled cells or recycled components.

Before battery assembly, each candidate cell is charge recycled to ensure it will operate at the correct current and within the specified cut-off voltages of the Battery Management System. The cell is then charged to a specific voltage to match other candidate cells for that battery. Finally, the internal resistance is measured to ensure it's within a safe range of the other candidate cells to be included in battery assembly.

If the cells' initial voltages or internal resistances are mis-matched, the battery will underperform. For example, if 9 out of 10 cells in a Lithium Ion 36V 10S1P (10 single cells in series) battery are 3.6V with one at 3.1V, then under load conditions, when this last cell reaches its voltage cut-off threshold (eg ~3.0V), the BMS (Battery Management System) will detect the breach and will cut the connection to load; this despite the overall battery voltage of 34.5V (or almost 40% of available charge left in the other cells).

Likewise, during the charge cycle, cells that have higher internal resistance or lower voltages will not reach full voltage at the same rate as the other cells. If this discrepency is material it can mean that the battery never reaches its full charge potential. For example, just one cell exhibiting a significantly lower internal resistance in a LiFePO₄ battery will result in it reaching full 3.6V charge ahead of the others. A BMS will endeavour to drain some of the excess charge from this cell so that the others may "catch up", but may be unable to prevent it from exceeding its high voltage cut-off threshold. In this situation, in order to prevent cell damage (or in the case of Li-ion batterries, thermal runaway and cell damage), the BMS will cut the charge connection to the battery with all of the other cells possibly well below their full charge potential.

Strict "Cell matching" is fundamental to quality of Radenite batteries. It improves the capacity performance of the battery and prolongs service life.

See below for important information about how the essential safety features of a BMS can eventually lead to reduced usuable battery capacity.

2. Welding

Matched cells are mounted in a lattice ABS plastic framework. This provides venitlation between cells as well as structural integrity for the battery that doesn't rely on inter-cell welded connections for strength.

Inter-cell connections using pure nickel connector strips are spot-welded to cell terminals. Depending on the battery, BMS sense/drain wires are either JST™ connections from a BMS or soldered to the BMS weld points.

No solder is used directly on cells.

3. Wiring and Thermal Management

Appropriate AWG-guage heat-resistant silcone-insulated wire is used to connect the charge and discharge ports to the BMS. BMS voltage sense wires are connected to the battery via individual welded nickel connection tabs. Each tab is protected with shrink tubing. Connections to the BMS load and charge wires are soldered. The wire from the BMS to the battery -ve terminal is soldered to nickel connection tabs which are then spot welded via nickel tabs to the battery -ve cell(s).

If the battery is a model that includes additional thermal protection, then a 10KΩ NTC thermistor is inserted into the centre of the pack and a third wire is added to the battery for thermal cut-out management. Radenite uses NTC thermistors with a β (Beta) value of 3950.

4. Testing

After preliminary assembly, each battery is charged to ensure that it is able to reach full pack voltage/capacity and verify that the BMS cuts the charge and loads at the required threshold protecting the battery and the user.

The discharge (load) terminals are short-circuited to verify the BMS protection circuitry activated. The BMS is then reactivated by applying the battery's nominal voltage across to the Charge terminals.

Finally an electronic load tester is then used to drain the fully charged battery at the maximum current rating to ensure the battery stays within safe operating limits.

5. Finishing

Following successful testing, the battery discharge and/or charge cables are secured internally with cable ties. Exposed nickel connection tabs are insulated and the cell terminals are covered in adhesive battery insulating material. Two transparent layers of shrink wrap are applied and finally the battery warning label is applied, specifying its operating limits and Radenite's contact details.

Important information about Lithium Ion Battery Management Systems

All Radenite batteries are fitted with Battery Management Systems which provide the following features:

• Battery short circuit detection and load cut-off
• Battery over current detection and load cut-off
• Cell over-voltage detection and charge cut-off
• Cell under-voltage detection and load cut-off
• Cell balanced charging

Some batteries may be fitted with additional protection such as fused external charge and load connections and/or NTC thermal cut-out protection, this will be clearly stated in the battery specifications.

NOTE: While every effort is made to harmonise cell voltages and internal resistances prior to battery assembly, over time, cell voltages and internal resistances will inevitably drift. The BMS will endeavour to "iron out" small voltage discrepencies during the charge cycle, but when these differences exceed the capabilities of the balanced charge circuit, the BMS will cut the charge cycle or the load when a cell's voltage has drifted outside the thresholds; this despite all other cells being able to receive more charge or deliver more charge.

In some cases, (e.g. over-discharge, short-circuit, &tc) the output current is cut. To restore voltage to the battery's terminals, connect it to a compatible charger. (see "What if I have no voltage.." for further details).

The series cell balancing provided by the BMS is complemented by the natural voltage balancing that occurs between any parallel connected cells in a Radenite battery.

Without the protection features of a BMS, there is substantially increased risk of thermal runaway (Li-ion) and/or cell damage (Li-ion & LiFePO₄) if over-charged and cell damage if over-discharged.

Trying to diassemble a battery or remove a BMS can increase risk substantially and will void the warranty.