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Cradle Operation

Orientation​

The cradle is used to contain the lithium battery “core” of the overall battery assembly. It is designed to be easy to use and trouble-free.

The cradle should be installed so the battery opening is away from the typical personloading side. In other words, when exiting the forklift, you should exit AWAY from the robot while parked in the hallway to prevent tripping the safety light curtain near the robot.

The power-button for the cradle is usually located next to the battery-load location

since this is always accessible, however for older cradles the cradle power button is located on the opposite side of the cradle near the cable connection to the cradle. Keep in mind that the Cradle is separate from the Pack, and both systems have a “power” button. The Pack must be in “standby” mode (i.e. power button is “flashing”) before it will connect with a cradle that is searching for a Pack.

Castings are bolted to the sides or bottom of the cradle and add ballast to the overall assembly. In this way, the cradle and battery can supply the proper counterbalance for many forklift types while using a common assembly for the battery interface.

Controls / Indicators​

Cradle Power Button​

The cradle utilizes an internal control board and 12V, 5Ah battery to facilitate several functions relating to the system. If the Cradle has been idle for more than 6 hours or has had a battery removed for more than 10 minutes , the cradle will shut down to preserve the energy in the cradle’s small keep-alive battery.

To instruct the cradle to search for a battery, press the silver power button on the side of the cradle and watch for it to slow-flash.

Slow-Flash : Searching for a battery. Steady: Battery Connected and Contactor Closed (Enabled)

If the power button light-ring does not start flashing, the system will need to be serviced.

In most cases, this is a simple operation and involves replacing an ATO style fuse or 12V “hotel” battery.

Pack Power Button​

The Pack and Cradle will stay powered for up to 6 hours if unattended or idle (charge / discharge current less than 10A). If the Cradle turns off and the forklift is without power (no light on the power button on the side of the cradle), the operator only needs to press the silver button on the side of the Cradle to turn on the cradle control board and reconnect with the Pack.

If the Battery System is shut down for over two weeks , the Pack will go into deep sleep mode to minimize discharge. This can be seen by checking the silver power button on the side of the Pack. If the button’s ring is not flashing green, the Pack is shut down and should be re-enabled if powering on the cradle.

A Pack in deep sleep is not typical and only occurs if the cradle is not turned on for an extended period of time (i.e. – maintenance or storage).

Battery Discharge Indicator (BDI)​

The BDI is used to show the operator the onboard drive battery’s state of charge (SoC). The battery may be fully discharged as needed, however regular discharge into the red zone may reduce the lifespan of the battery.

Control Lights​

Three lights are used on the left side of the display.

• Power (Green / Red) o Red: Cradle powered, no Pack is connected o Green: Cradle powered, and Pack is communicating • Maintenance (Yellow) o Cradle is requesting a power limit from the truck. o Reduce load and return to the swap station to change the battery. • Stop (Red) o Fast-flash: The system is shutting down o Solid: The system is shut down

SOC Lights​

A stack of 13, 2-color LEDs capable of making red, yellow, or green colors.

When the stack of LEDs is all on, the battery is full. When the State of Charge of the battery is low the BDI LEDs will turn yellow, then red and begin flashing. Operation in the yellow or red zone of the BDI indicates that the battery may not have enough power to supply a very intense load from the vehicle and operation should be limited if possible.

When the BDI shows yellow or red and begins beeping, the battery should be changed for a charged battery as soon as practical.

5.2.3.3 Sounds

Startup: Short Chirp – Startup sound-test Operation – 3 yellow LEDs: Slow-Beep, short

  • Indicates entering low-SoC region.

  • Limit power and return for swap.

Operation – 2 Yellow LEDs: Slow Beep, short Operation – 2 Red LEDs: Slow-Beep, short

  • Extremely low SoC region

  • Limit power and return for swap.

  • Battery will shut off, can be turned on.

Operation – 1 Red Flashing LED: Fast Beep, Continuous

Using the Cradle​

Returning Early (preferred)​

While the system will attempt to limit operation that reduces the life of the battery, the operator may choose to return the battery to the Hive at any time before the yellow zone (3 LEDs) to extend the lifespan of the battery even longer.

Since these are Lithium-ion batteries, they DO NOT suffer from the effects of charging memory or not fully discharging them before charging. In fact, over-discharge of batteries leads to a reduced lifespan.

Returning Late / Low SoC (avoid)​

If you miss the LED and Sound warnings indicating you should go change your battery, there is a chance the battery will need to shut down to prevent damage to itself. When in this Shutdown mode, the battery will attempt to find a moment when the current draw from the forklift is low, before disabling the power output.

A shutdown will typically occur after a period of approximately 35 seconds of alarms (beeping and flashing LEDs).

Shutdown Warning System (SWS)​

There are typically two shutdowns that the system uses in the event of a fault:

  • 30 seconds (common)

    • Mild over-temp, low SoC, mild sustained under/over voltage

  • 10 seconds (usually blocked by common shutdowns)

    • Critical temp, very low/high cell voltage, excessive current

In both cases, another 10 second timer will be added to attempt to find a moment when the current draw from the battery is low to prevent shutdowns when the forklift is working.

Shutdowns due to SWS will typically be reset after the shutdown and the system can restart when the fault is cleared.

Battery Lifespan Considerations​

When operating the battery in the yellow or red zones of the BDI forklift drive and lift speed can be tempered to extend the lifespan of the batteries.

If your vehicle has a CAN communication connection, it will automatically limit the forklift power based on the capabilities of the battery and thus improve the lifespan automatically. In this situation, you can still return the battery to the Hive as soon as the BDI indicates 3 yellow LEDs to maintain optimal conditions for long battery lifespan.

Storage​

When storing the Cradle and/or Pack for more than 3 months, contact the manufacturer for more information.