Batteries

Battery Types

AGM Batteries

AGM batteries (Absorbent Glass Mat) are lead acid batteries that contain a fibreglass mesh between the battery plates. This mesh contains the electrolyte and prevents leakages even if the batteries are stored upside down or when the outer casing is cracked. This technology is well proven, cheap and widely available. Its drawbacks are a low energy density, resulting in high weight for a given capacity, and a limited number of charge-discharge cycles.

Their capacity will reduce over time until at some point (approximately after two years of use) the robot’s available uptime is no longer sufficient and the batteries need to be replaced.

There are several measures to prolong the life of AGM batteries and to save costs and resources:

• Recharge the robot whenever possible.
• Avoid deep discharge and reaching the automatic shut-down voltage.
• Charge the robot while it does not need to move, for example while programming for several hours.
• Do not leave the robot with empty batteries for a long time.

Lead batteries in AGM design are generally very tolerant and significantly less dangerous than traditional lithium-ion-batteries. Heat, age or wrong treatment may nevertheless cause damages.

Attention

Regularly check the battery’s condition, at least once every month! The following points indicate battery damages:

• Deformation or stretching of the battery’s casing
• White or brownish spots at the battery contacts or other metal parts
• Excess heat
• Strong smell of sulphur
• Liquid below the battery

As soon as you notice any kind of damage the batteries must no longer be used and must not be charged any further! Please contact Neobotix immediately.

LiFePO4 Batteries

Lithium iron phosphate batteries, also known as LiFePO4 or LFP batteries, are a rather recent development in lithium-ion battery technology. They provide several benefits compared to AGM batteries as well as other lithium-ion designs.

LiFePO4 batteries are not necessarily smaller than AGM batteries but save about 60% of weight at the same nominal capacity. Under actual use conditions their usable capacity is even higher than that of AGM batteries, because they can be fully discharged. Similar deep discharge of AGM batteries quickly leads to loss of capacity or other damages.

Thanks to their chemistry LiFePO4 batteries provide a very stable output voltage and support fast charging. This not only reduces the recharge time significantly but also allows short periodic charging at convenient locations inside the workspace. When done properly this in-process-charging enables the robot to operate 24/7 without being taken out of operation for recharing.

LiFePO4 batteries are intrinsically much more stable than other lithium based designs. In addition our LiFePO4 batteries also contain a sophisticated battery management system (BMS) that constantly monitors their condition and health. The status information of the BMS is read by the robot’s control software and used to indicate potential problems.

Warning

If you notice anything unusal about the LiFePO4 batteries immediately switch off the robot, stop charging and contact Neobotix!

Tip

The integrated battery management system of the LiFePO4 batteries monitors the voltage and current and uses this to calculate the charge status of the battery modules. The end of charging at 100 % battery charge serves as the reference point. To ensure that the charge level can be reliably determined at all times, the batteries must be fully charged regularly, preferably once a week.

If the batteries are not charged to 100 % over a longer period of time, the reliability of the charge level estimation decreases continuously. As a result, less capacity can actually be utilised and, in the worst case, the batteries switch off unexpectedly due to undervoltage.

Waking up of LiFePO4 Battery Packs

Lithium-based batteries may only be transported with a low residual charge and in a safe condition. For this purpose, the rechargeable batteries used by Neobotix can be set to a special power-down mode in which the battery management system only consumes minimal energy and the battery can no longer be activated without further ado.

Note

In the event of a fault or deep discharge, the batteries also switch to power-down mode and can be woken up again in most cases as described here.

To wake up a battery pack, proceed as follows:

1. Plug the supplied dummy plug into the 8-pin communication connector of the battery.

   

2. Connect the power supply unit to mains.

   

3. Plug the green high-current connector 1 into the main connection of the battery and unplug it again after approx. one second. To do this, do not pull on the cables but grasp the plug on the sides of the green housing.

   

4. Plug the green high-current connector 2 into the main connection of the battery and unplug it again after approx. one second.

   

5. Unlock the dummy plug by pressing the catch and carefully pull it off the battery. Do not pull on the cables, but grasp the plug on the sides of the black housing.

   

6. The battery is now in sleep mode and can be installed and used.

Warning

When installing the batteries, make sure not to mix batteries from several robots. The combination of battery packs of different ages and especially with different charge levels can cause damage to the batteries and the electrical system of the robots.

Note

Also make sure that the battery packs are installed in the correct position in the robot. For the last battery pack in the system, to which only one communication cable with a black plug is connected, the CAN terminating resistor must be activated. To do this, push the white switch in the red DIP housing outwards to the ON position. If more than one battery pack is used, the resistor must not be activated on the remaining battery packs (position 2, inside).

Charging

With Charging Station

The usage of our different charging stations is documented at Charging Stations.

With external Battery Charger

The battery of the mobile robot consists of several batteries connected in series and / or in parallel. The resulting battery pack can be charged conveniently and safely by using the provided battery charger.

The battery charger needs a power supply of 230 VAC, 50 Hz.

The charger must be placed in a dry environment. Do not cover the housing, so appropriate cooling is possible, and avoid direct sunlight.

First connect the battery charger to the charging connector and then turn on the charger. After the battery has been fully charged first turn off the battery charger and then disconnect the cable.

Warning

• Never connect or disconnect the battery charger while it is switched on! Increased wear of the contacts due to electric arcs may occur. The battery or other electrical components may be damaged.
• Always make sure that the charging connector is fully inserted into the socket and properly secured. An incomplete or insufficient connection can cause high heat and significant damages.
• Only use batteries and chargers supplied by Neobotix. Using unsuitable batteries or battery chargers can lead to serious damages, injuries and hazards!

Recharging is done completely automatic after the connection is established and the battery charger is connected to the main power supply and switched on. For recharging it does not matter whether the robot is switched on or off. The only difference is the time needed for a full recharge. With the on-board electronic active, a recharge might take significantly longer, depending on the workload of the on-board computer.

The battery charger features an overload protection, thus allowing the robot to be permanently (e.g. overnight) connected to the charger. If the robot remains switched on while being connected to the charger (e. g. while programming) it might be necessary to switch the battery charger off and on once a day.

Please also read the documentation that was supplied together with the battery charger.

With integrated Battery Charger

Some robots feature an integrated battery charger. These robots can be charged by first plugging the charging cable into the robot’s charging socket and then plugging the other end into a normal power outlet as described above.

Warning

Always make sure that the charging connector is fully inserted into the socket and properly secured. An incomplete or insufficient connection can cause high heat and significant damages.

The charging process starts automatically once the connection to mains has been made. As with the external charger the robot can be charged both when switched on or off.

Recycling

Both battery types used in Neobotix robots are leak proof and very safe.

Warning

They still contain highly reactive chemicals and must never be opened or damaged to avoid serious damage or injuries!

Attention

• Under European law all kinds of batteries must only be returned to certified recycling companies. Please get in touch with Neobotix if you are unsure about how to recycle or dispose of used batteries.
• You can also return all old or wasted batteries from your Neobotix product to Neobotix free of charge for proper recycling.
• Please make sure to fully cover the battery contacts to guarantee their electrical insulation before shipping or disposing of old batteries. This will prevent short circuiting, damages and injuries.