Blue Robotics Lithium-ion Battery Guide
Lithium-ion Battery Safety
Lithium-ion batteries are dangerous when not used properly. Improper operation and maintenance can also severely shorten battery lifespan. Please read and understand all the information in this guide to ensure you are using Blue Robotics batteries safely and getting the best performance out of your batteries.
- Only use battery chargers designed specifically for lithium-ion/polymer batteries.
- Do not charge a battery above its maximum voltage. This will lead to battery explosion.
- Do not discharge the battery below its minimum voltage. This kills the battery.
- Do not exceed the maximum charge or discharge rate. This will damage the battery.
- Do not get the batteries wet. A wet battery may short or will eventually corrode and fail.
- Do not puncture, crush, cut, or disassemble the batteries.
- Do not burn or expose batteries to temperatures above 50°C (122°F).
Blue Robotics Battery Quick Information
The relevant information for all Blue Robotics batteries is provided below for reference.
| Lithium-ion Battery (14.8V, 18Ah) | |
|---|---|
| Part Number | BR-100842 (BATTERY-LI-4S-18AH-RX-RP) |
| Appearance | Cylindrical with black wrapping |
| Nominal Voltage | 14.8 V (3.7 V per cell) |
| Maximum Voltage | 16.8 V (4.2 V per cell) |
| Minimum Voltage | 12.0 V (3.0 V per cell) |
| Maximum Discharge Rate | 60 A (continuous) 132 A (burst) |
| Charging Settings | |
| Charging Parameters | Lithium polymer (LiPo) |
| Charging Mode | Balance charge |
| Cell Count | 4 (4S) |
| Ending Voltage | 16.8 V |
| Recommended Charge Rate | 10 A |
| Maximum Charge Rate | 20 A |
| Lithium-ion Battery (14.8V, 15.6Ah) | |
|---|---|
| Part Number | BR-100839 (BATTERY-LI-4S-15.6AH-R1-RP) |
| Appearance | Cylindrical with white wrapping |
| Nominal Voltage | 14.8 V (3.7 V per cell) |
| Maximum Voltage | 16.8 V (4.2 V per cell) |
| Minimum Voltage | 12.0 V (3.0 V per cell) |
| Maximum Discharge Rate | 60 A (continuous) 132 A (burst) |
| Charging Settings | |
| Charging Parameters | Lithium polymer (LiPo) |
| Charging Mode | Balance charge |
| Cell Count | 4 (4S) |
| Ending Voltage | 16.8 V |
| Recommended Charge Rate | 10 A |
| Maximum Charge Rate | 20 A |
| Lithium Polymer Battery (14.8V, 10Ah) | |
|---|---|
| Part Number | BR-100346 (BATTERY-LP-4S-10AH-R1-RP) |
| Appearance | Rectangular with black wrapping |
| Nominal Voltage | 14.8 V (3.7 V per cell) |
| Maximum Voltage | 16.8 V (4.2 V per cell) |
| Minimum Voltage | 12.8 V (3.2 V per cell) |
| Maximum Discharge Rate | 90 A (continuous) 120 A (burst) |
| Charging Settings | |
| Charging Parameters | Lithium polymer (LiPo) |
| Charging Mode | Balance charge |
| Cell Count | 4 (4S) |
| Ending Voltage | 16.8 V |
| Recommended Charge Rate | 10 A |
| Maximum Charge Rate | 15 A |
| Lithium-ion Battery (22.2V, 28Ah) | |
|---|---|
| Part Number | BR-100313 (BATTERY-LI-6S-28AH-ADAPTED-R1-RP) |
| Appearance | Cylindrical with blue wrapping |
| Nominal Voltage | 22.2 V (3.7 V per cell) |
| Maximum Voltage | 25.2 V (4.2 V per cell) |
| Minimum Voltage | 18.0 V (3.0 V per cell) |
| Maximum Discharge Rate | 110 A (continuous) 240 A (burst) 90 A (when using XT90 adapter) |
| Charging Settings | |
| Charging Parameters | Lithium polymer (LiPo) |
| Charging Mode | Balance charge |
| Cell Count | 6 (6S) |
| Ending Voltage | 25.2 V |
| Recommended Charge Rate | 16 A |
| Maximum Charge Rate | 32 A |
Battery Charging
Only use battery chargers designed specifically for lithium-ion/polymer batteries, attempting to use another type of charger will damage the battery. The charger must have a balance charge mode and support four cell (4S) or six cell (6S) batteries.
We recommend using the Blue Robotics H6 PRO Lithium Battery Charger to charge Blue Robotics batteries. It is preconfigured with the correct settings to charge Blue Robotics batteries safely. You can view the full H6 PRO Charger user instructions here.
If you are not using the Blue Robotics H6 Pro Lithium Battery Charger, you can find the required charging settings for every Blue Robotics battery in the quick information section above. Follow the guidelines below and always refer to your charger’s user manual.
- Inspect the battery for swelling, leaks, or other signs of damage before charging. Do not charge damaged batteries.
- Set the charging parameters to the lithium polymer (LiPo) setting. This will set the correct maximum charge voltage to 4.2 V per cell. Using the incorrect parameter may overcharge the battery, leading to battery explosion.
- Use the charger’s balance charge mode whenever possible. Balance mode will keep all the cells in the battery at the same charge level. Cells that are not properly balanced may become overcharged and can lead to battery explosion. Occasionally quick charging is fine as long as the battery will be balanced later.
- Set the correct cell count, either 4S or 6S depending on the battery you are charging.
- Batteries should be charged at the recommended charge rate regularly for best performance. They can be charged at the maximum charge rate occasionally for faster charging. Do not exceed the maximum charge rate as this will damage the battery.
- Charge batteries in a safe area and do not leave them unattended while charging. Keep an eye on battery temperature while charging. If it gets unusually hot, discontinue charging and check for issues.
- For added safety, consider using a fireproof charging bag or box while charging.
Discharging/Using Batteries
Connect the battery’s main cable to your device to power it. The voltage of a fully charged battery will start at its maximum voltage then gradually fall as charge is depleted. Blue Robotics batteries do not have built-in battery management systems (BMS) to prevent overdischarging. The battery voltage must be monitored to prevent discharging below the minimum voltage level.
- Stop using the battery before the voltage falls under the minimum voltage level. Discharging below the minimum voltage will kill the battery.
- Batteries can safely sustain a constant discharge up to the continuous maximum discharge rate.
- Batteries can sustain a discharge up to the burst discharge rate in short bursts up to 10 seconds at a time. Exceeding this will overheat and damage the battery.
- Note that the maximum safe discharge rating is dependent on adequate cooling to keep the battery below 50°C. If used in an enclosed space without airflow, constant current draw must be decreased appropriately to keep the battery at a safe temperature.
- Some Blue Robotics batteries have a negative temperature coefficient (NTC) thermistor that can be used to monitor the battery temperature.
Storing Batteries
When batteries are not being used and will be put away for storage, use the storage function on your charger to put the batteries at the correct storage charge level. Lithium batteries must be stored at a reduced charge level, usually around 40–60% of full charge, to keep them healthy. Storing a battery fully charged, or deeply discharged, can degrade capacity or permanently damage it over time. The Blue Robotics H6 PRO Lithium Battery Charger, and most other lithium battery chargers, have a storage function that will charge or discharge a battery to the proper storage charge level.
Once the batteries are at the appropriate charge level, follow these guidelines for storage:
- Store lithium batteries in a cool, dry location at a temperature below 50°C (122°F), and ideally between 15°C and 25°C (59°F and 77°F). Avoid locations with high heat or direct sunlight, as excessive temperatures can degrade battery capacity.
- Ensure the storage environment is dry with low humidity. Excess moisture can lead to corrosion or internal damage, affecting the battery’s performance and lifespan.
- Keep batteries away from flammable materials or potential ignition sources. Consider using a fireproof container or a designated storage area specifically designed for batteries to minimize fire hazards.
- Batteries will self-discharge slowly while in storage. On average, they can lose about 0.5–5% of their charge per month while in storage, depending on factors like ambient temperature, state of charge, age, and health. Periodically check your batteries every few months to ensure their charge does not fall below the minimum safe voltage, and top-up the charge as necessary.
Lithium Polymer Battery Puffing/Swelling
This information only applies to the rectangular Lithium Polymer Battery (14.8V, 10Ah). The improper use or maintenance of lithium polymer batteries can lead to a buildup of excess gas within the battery, making the battery appear puffy or swollen. Follow these safety guidelines if you notice your battery begins to look puffy or swollen.
- Very slight puffing or swelling of the battery is not ideal but is generally safe to continue use in most cases. Slight puffing and swelling are strong indicators that the battery is being stressed and more care should be taken to maintain good battery health:
- Make sure to put the battery at storage charge level when not in use.
- Charge at the recommend charge rate or lower.
- Avoiding overdischarging or exceeding the maximum continuous discharge rate.
- Keep the temperature below 50°C (122°F).
- Significant puffing or swelling is very dangerous. If your battery appears very puffy or swollen, discontinue use and dispose of it immediately.