Orion Jr. BMS Manual
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5. Charge Safety Signal
(Out)
An open drain digital on/off signal used as a
safety switch for a
charger. This signal is normally connected to the charger or
connected to a relay which enables AC power to the charger such
that the lack of this signal will cause the charger to be inactive.
This is a signal current level (175mA max) and should be amplified
for controlling large contactors or relays (see electrical specs.)
6. Power Ground
This is the ground for the supply power for the BMS. Both power
sources (READY and CHARGE) share this ground, and grounds
for these power sources must be bonded together externally.
7. Multi Purpose Enable
An open drain digital on/off signal with configurable behavior. This
is a signal current level (175mA max) and should be amplified for
controlling large contactors or relays (see electrical specs.) Please
see the software manual for a complete list of available functions.
This output is watchdog backed and will turn off when certain
faults occur, regardless of programmed settings.
8. Thermistor Ground
One leg of each of the two thermistors should be grounded to this
ground. Both thermistors share this ground return.
9. Multi Purpose
Output 1
The behavior of this multi-purpose output is configured in software
for additional functionality. This output is often used to drive an
LED to indicate the presence of error codes, but can also be used
as a CAN controlled output as well as other functions. Please see
the software manual for a complete list of available functions. This
output is NOT watchdog backed and may remain on when certain
faults occur.
10. Thermistor 1
12. Thermistor 2
16. Thermistor 3
One leg of each of the thermistors should be connected to the
respective thermistor pin. These pins connect to 10K NTC
thermistors.
Analog 5v Outputs:
11. State of Charge
13. Charge Current Limit
14. Discharge Current
0-5V analog outputs that represent charge current limit, discharge
current limit, and state of charge.
15. Multi Purpose Input
This is an input signal that can have multiple different input
functions such as redundant keep-awake power signals, clearing
DTC fault codes and other functions. Please see the software
manual for a complete list of available functions. The voltage
range for this pin is 9-60V.
17, Multi Purpose
Output 2
The behavior of this multi-purpose output is configured in software
for additional functionality. Please see the software manual for a
complete list of available functions. This output is NOT watchdog
backed and may remain on when certain faults occur.
19. CAN_L
20. CAN_H
CAN interface with high and low signal lines. Only available on
units ordered with CANBUS. Unless special ordered, the BMS unit
has a termination resistor installed inside the unit (120 ohm).
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Wiring Main Connector
Fusing
Important: As with
all electrical devices, all wires connected to the Orion Jr. BMS unit must be current
limited at their source. Any circuit connecting to the BMS must be current limited with an appropriately
sized fuse (or other current limiting device) to prevent overloading wires in the event of a short. The
external fuse must be sized properly to protect the conductors and must specifically have a DC
voltage rating of no less than the maximum possible working voltage and an appropriate DC
interrupting current rating for the application.
The maximum fuse size permitted for the CHARGE or READY power, any of the open drain output
pins, or multipurpose input pins is 3A, but smaller fuses may be used.
Two diagrams showing fuse placement.
Power Supplies
Operating power is supplied to the Orion Jr. by two separate power sources. The power supplies will
not backfeed each other due to internal diodes. The Orion Jr. consumes approximately 1-2 watts for
operating current. Actual current varies depending on supply voltage and may be higher if additional
devices are connected to the Orion Jr. Operating current will be drawn from the higher voltage source if
both sources are on at the same time.
The Orion Jr. units are designed to be powered either from an auxiliary power source or from the pack
voltage and operate on 12-48 volts nominal for operating power. Voltages between 9V and 60V are
acceptable for continuous operation. Voltages below 9V may cause the BMS to turn off, and voltages
over 60V will damage the BMS unit. The supply voltage may not exceed 60V at any time.
Orion Jr. BMS Manual
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If pack voltage is used to supply operating current to the Orion Jr. unit, care must be taken as
other I/O pins, including the thermistor inputs on the Main I/O connector, are not electrically
isolated from the supply power.
Revision C units have been tested to withstand limited damaging transients on the CHARGE and
READY power inputs of up to +/- 300 V, 2mS duration with 5 ohm source impedance as defined in
pulse 1 of 1SO 7637-2 (open drain outputs have been tested to withstand transients up to +/-200V,
0.05mS duration with 2 ohm source impedance as defined by ISO 7637-2). If transients beyond these
rating are expected on any input to the BMS including the ready or charge power sources, external
transient protection must be supplied (Note: very strong transients may also damage other equipment
or even the battery cells themselves).
If the BMS is powered directly from the battery pack it is protecting, care must also be taken
such that the operating current powering the BMS does not over-discharge the battery in the
event the battery is not charged for an extended period of time. Over-discharge of a battery pack
may destroy the entire battery pack in one single event, so this is essential. The Orion Jr. unit has an
optional low-power shutdown mode which causes the BMS to shutdown and draw about 0.1 watts
when the voltage of the lowest cell drops below a certain voltage. This optional low power shutdown
feature must be enabled in software (disabled by default). On revision A and B units, it may cause the
BMS to lock in the “off” state for up to 5 minutes when triggered, even after power is disconnected.
This
feature will slow down discharge, but it will NOT fully protect the battery as the unit will still
draw about 0.1 watts or up to about 20mA from the battery pack even when in shutdown and
this will eventually drain the battery pack. Lithium-ion cells can be destroyed in one cycle when
over-discharged.
Ready Power Source: This is the primary power source for the Orion Jr. BMS unit. This power source
can be thought of as the “ignition” power source when the BMS is used in mobile applications.
When
power is present at this source, the BMS will allow both normal charge and discharge. When powered
only by this power source (i.e. charge power is not present), the BMS will not engage the charger safety
output (usually used to control a battery charger) and will not allow cell balancing.
Charge Power Source: This power source should be energized when the battery is in a defined
charging phase such as being fully charged by an AC battery charger. When power is present at this
pin, the BMS will enter charging mode, which enables cell balancing and enables the charger safety
signal output. For most applications, this is used when the BMS is in a defined charging phase from AC
power. Because of this, CHARGE power is normally provided by a small AC / DC power adapter
powered off the mains.
The BMS will fully operate with both the charge and ready power sources powered at the same time. If
both CHARGE and READY power sources are energized at the same time, the BMS will allow normal
charge and discharge and will also enable the charger safety output and balancing.