Below you will find answers to the questions we get asked the most about BWB LiFePO4 batteries
Before Purchase
LiFePO4 stands for Lithium Iron Phosphate, which is a type of rechargeable battery known for its high energy density and long cycle life
LiFePO4 batteries offer several benefits, including high energy efficiency, long cycle life (up to 3,000-8,000 cycles), lightweight, and excellent stability.
LiFePO4 batteries are known for their enhanced safety due to their stable chemistry, which makes them less prone to thermal runaway and fires compared to other lithium-ion batteries like Li-ion and LiPo.
LiFePO4 batteries are used in various applications, including electric vehicles (EVs), RVs, solar energy storage, portable electronics, power tools, and UPS systems.
- Alternators (in Vehicles): The alternator in the vehicle can charge the LiFePO4 battery when the engine is running. You can use a DC/DC Charger with Lithium option.
- Solar Panels: LiFePO4 batteries are commonly used in solar energy storage systems. Solar panels can be connected to a charge controller, which then charges the LiFePO4 battery bank. Make sure the Charge Controller is compatible with LiFePO4 batteries.
- AC/DC Chargers: You can set your chargers voltage to lithium. Please take note of your battery voltage type to manually set the voltage. Like for a 12V system, the max charge voltage is 14.6V. Learn more about our LITHIUM CHARGERS.
Yes, LiFePO4 batteries require a charger specifically designed for them. Using the wrong charger can damage the battery or reduce its lifespan. Please make sure to use a lithium-compatible charger.
LiFePO4 batteries can last up to 10 years or more, depending on usage patterns and how well they are maintained.
In some cases, LiFePO4 batteries can be used as a replacement, but it’s essential to check voltage, capacity, and compatibility with the device’s charging and discharging requirements.
Remember that specific details and characteristics of LiFePO4 batteries can vary depending on the manufacturer and product, so always refer to the manufacturer’s documentation and recommendations for the most accurate information.
We build our BWB LiFePO4 batteries in Australia. Major battery components are sourced directly from the best manufacturers with reputable background and experience. This means you will be buying the best quality product for your lithium battery needs.
Take a look at the video of how we build the LiFePO4 batteries in Australia.
We use GFB Class-A, EV-Grade prismatic cells with 100% charge & discharge currents.
Cycle Life: 3,000 for Electric Vehicles & 8,000 for Deep Cycle use.
To read more about our LiFePO4 prismatic cells, please click here https://www.bigweibattery.com.au/products/lithium-iron-lifepo4-battery-cells/
With BWB LiFePO4 Battery, the usable power is 90%. Unlike AGM, you can only draw up to 50%.
These LiFePO4 cells come from one of the top three largest and most reputable lithium manufacturer’s in China – GANFENG Lithium.
Ganfeng Lithium Group covers a wide swath of the lithium battery supply chain, from lithium resource development, refining and processing to battery manufacturing to battery recycling. it’s the Company’s products are widely used in electric vehicles, energy storage, 3C products, chemicals and pharmaceuticals. The Group’s lithium resources are located across the globe and it is the only Company in the lithium industry that has the commercial scale technologies to extract lithium from brine, ore and recycled materials. The Groups lithium compound capacity ranks third worldwide and first in China, and is the worlds largest lithium metal producer. The Group has complete battery manufacturing and recycling technology, providing sustainable value-added solutions to battery manufacturers and electric vehicle manufacturers.
Read more about GANFENG LITHIUM by visiting their website Lithium Metals|Lithium Compounds–Ganfeng Lithium Co.,Ltd
We have been in the battery business in China for more than 30 years now. We know exactly where to source all of the best quality components, from Lithium cells to BMS including cables, etc. We partner directly with the best companies in the China. No Middle Man. Therefore, it makes our BWB LiFePO4 products more affordable and high quality.
Disclaimer: We would like to thank Blue Sea Systems for this article below. You can find more of their electrical system frequently asked questions in their website.
Choosing the right wire size for your DC electrical project is important, since a wire that is too small can overheat and possibly start a fire. The American Boat and Yacht Council (ABYC) publishes charts with valuable detail to help experienced boatbuilders and installers determine what wire size they need. Although these charts are an excellent resource, they are a bit intimidating. This technical brief distills the information on these charts to a more manageable size for installers and boatowners alike.
Quality marine wire, as specified by ABYC standards, will always be stranded rather than solid, and always tin-plated copper. In addition, the DC Wire Selection Chart shown below assumes a wire insulation rating of 105°C. A lower rating will decrease the current-carrying capacity of the wire.
To use the chart included with this technical brief, follow the instructions below.
Choosing the correct wire
A Locate the CURRENT IN AMPS of your appliance across the top of the chart. Most electrical products include a rating label, or you can find the amperage rating in the documentation that came with the product.
B Find circuit LENGTH IN FEET along the left side of the chart. Note that the total length of the circuit is the roundtrip distance from power source (usually the battery) to the product and back.
C Select the CIRCUIT TYPE. Allowable voltage drop is based on whether a circuit is critical or non-critical.
Critical circuits, with 3% allowable voltage drop, include
- Panel main feeders
- Bilge blowers
- Electronics
- Navigation lights
Non-critical circuits, with 10% allowable voltage drop, include
- General lighting
- Windlasses
- Bait pumps
- General appliances
Follow down the column until you find your circuit’s LENGTH IN FEET.
D Intersect CURRENT IN AMPS with LENGTH IN FEET to identify the wire size.
Example: A windlass rated 80A is 25’ from the battery. Circuit length is 50’, circuit type is ‘non-critical’, and correct wire size is 4 AWG.
Click the image below to enlarge
Although this process uses information from ABYC E-11 to recommend wire size and circuit protection, it may not cover all of the unique characteristics that may exist on a boat. If you have specific questions about your installation please consult an ABYC certified installer.
The Circuit Wizard, at circuitwizard.bluesea.com, is a resource for a more detailed treatment of wire size selection for DC circuits. It allows you to input detailed information including wire insulation temperature rating and other derating factors. The Circuit Wizard is easy to use, and is accessible from any computer with an Internet connection.
Look for additional articles on the topic of selecting circuit protection at bluesea.com/support/articles/Circuit_Protection.
Got your BWB LiFePO4 Battery
BWB LiFePO4 batteries are made of brand new cells, which only have 25% power.
Please fully charge the battery before you use it.
For more information about BWB LiFePO4 batteries, please download BWB LiFePO4 User Manual & Warranty Policy (08.23)
If your charger allows, please set the parameter as the charging table below:
| Battery Voltage | 12.8V | 25.6V | 38.4V | 51.2V |
| Max. Charge Voltage | 14.6V | 29.2V | 43.8V | 58.4V |
| Float Voltage | 13.5-13.8V | 27-27.6V | 40.5-41.4V | 54-55.2V |
| Absorption Voltage | 14-14.4V | 28-28.8V | 42-43.2V | 56-57.6V |
BWB LiFePo4 batteries come with JBD BMS or DALY BMS.
And we also sell JK BMS.
Click the link below to get the instruction of the APP to different BMSes.
· When the voltage of each cell gets around 3.5V, means the battery charge capacity is nearly full, then the cells would charge much faster towards full capacity, and the cell voltage rise rapidly. This is normal and is a characteristic of LiFePO4 cells. One cell may charge quicker than the rest, and will reach 3.65V earlier than others.
Max charge per cell is set for 3.65V. (You can find this on the BMS parameter). Once one cell get 3.65V, BMS will stop charging the battery unit, and start balancing the voltage of cells.
Sometimes, the BMS will show an alarm when it’s fully charged (“cell voltage level high”). But after several minutes, it will disappear as long as charger has been disconnected, and the voltage difference will be balanced gradually by the BMS.
When a battery is fully charged, a significant voltage difference of 0.2V-0.5V is normal. (However, is shouldn’t happen when you are discharging the battery). The more you use the battery and charge it, the more you will see it stabilizes.
· When you are discharging the LiFePO4 battery, the voltage will drop fast at the beginning(3.4V), and will stabilizes when it’s under 3.3V. However, when the voltage get around 3.1V, it will start dropping rapidly until the battery is cut off by the BMS. The voltage drop rate can be different depending on the DOD (depth of discharge).
No. The BMS cuts off the battery supply when 90% of its power has been used. When this happens, simply charge back the battery. It’s best recommended you use at least a minimum of 10A lithium charger so that it activates the BMS quicker. Always remember that BMS also protects your battery from over-discharge. Attempting to use the battery after it has cut-off may take longer time to reactivate when recharging.
We don’t recommend you lay it either sideways or upside down. The lithium cells have pressure release valve which helps protects the cells when extreme pressure is happening and/or any excess of electrolytes may need released. To keep the battery safe, healthy, lasts longer and away from possible damage, keep it standing upright for maximum performance.
Yes, all our BWB LiFePO4 batteries are parallel capable.
Please do not parallel the battery to different voltage/ different capacity/ different type batteries.
When installing, fully charge the batteries separatly, then sit for 30 minutes before connecting together.
*NOTE: Slight variance of SOC or Amps may occur between the batteries in parallel. It is normal.
Some models of BWB LiFePO4 batteries are series capable. Please check product specifications or contact the Big Wei Battery support team before purchase.
Big Wei Battery supply voltage ranging from 12V to 48V and capacities extending up to an impressive 14kwh.
In situations that are not necessary, it is recommended to give preference to using a single battery rather than connecting multiple batteries.
3 YEARS LIMITED WARRANTY
Big Wei Battery warrants BWB LiFePO4 Battery to be free of defects in material and workmanship for the applicable 3-year warranty period. Warranty is only given to the original purchaser of this product. The warranty does not extend to subsequent purchasers or users. The 3-year warranty period starts from the date of the original purchase of the product.
The maximum liability of Big Wei Battery under this limited warranty shall not exceed the actual purchase price of the product.
To get more information about BWB LiFePO4 Warranty Policy, please click on the link below:
Having problems using your battery?
Check the Charger: Ensure that you are using a charger specifically designed for LiFePO4 batteries and that it is functioning correctly.
Inspect Connections: Ensure all connections, including the battery terminals and charger connectors, are clean and securely connected.
Check Voltage: Use a multimeter to check the voltage of the battery. If it’s extremely low (below the low cut-off limit), the charger may not recognize it. We also recommend to check voltage receiving charge and without charge (make sure there is no loads/draw/discharge). In such cases, use a low-voltage recovery charger or contact Big Wei Battery to get instructions for reviving a deeply discharged LiFePO4 battery and to provide the relevant information (example: voltage of battery).
If a 12V battery has been discharged too far, the voltage will fall well below 12V. If the battery has a voltage of less than 8V or if one of the battery cells has a cell voltage below 2.0V, the battery will have permanent damage. This will invalidate the
warranty. The lower the battery or cell voltage is, the bigger the damage to the battery will be.
If the voltage has dropped below 8V, the battery will not communicate via Bluetooth anymore. You can try to recover the battery by using an AC 240V charger.
Be aware that this is not a guaranteed process, recovery might be unsuccessful and there is a realistic chance that the battery has permanent cell damage resulting in a moderate to severe capacity loss after the battery has been recovered.
Reduce charge rate: If the battery is getting too hot during charging, try reducing the charge rate. Please check the specs of the battery to make sure the charging rate is at the safe level. Excessive heat generation can be harmful.
- Check for loose connections: Loose connections can cause over heating. Please check the terminals and other connections that may be loose or damaged that is causing heating.
Check ambient temperature: Charging at high ambient temperatures can lead to overheating. Charge the battery in a cooler environment if possible.
Inspect for damage: Check for physical damage to the battery or charger, such as bent connectors or damaged cables, which can cause resistance and heat buildup. You can also check the battery terminals or the case if there is specific spots on the battery where there shouldnt be hotter than the rest of the case.
It’s common to observe a notable discrepancy in cell voltage during the charging process, particularly when the battery is nearing full capacity, owing to the characteristics of LiFePO4 chemistry.
This unbalance can also occur during high discharge and charging rates; for example 100AH being discharge 90amps in approximately an hour. This would cause a inbalance in the cells because the BMS does not have enough amps to catch up with balancing the cells.
This inbalance can also occur with 0.5C~ dicharging and charging over 12 months or more. If this inbalance occurs you can have the cells balance again by charging the battery and letting it sit for period of time. You repeat this till the cells are balance. This lets the BMS catch up.
Notice that there will always be a cell higher than the rest and a cell lower than the rest, this is normal as how the current flows through the cells.
If the imbalance of the battery cells affects the battery’s operation, the BMS will automatically disconnect the battery to ensure safety.
Still need help?
