FAQ

Yes. LiFePO4 is an inherently safe chemistry and the most stable lithium-type battery on the market. REX lithium cells are CE, RoHS, FCC certified, which means they have been tested for: Short-Circuit Abnormal Charging Crush Impact Shock Vibration Heating Temperature Cycling Low Pressure (Altitude Simulation) All REX LiFePO4 batteries come with an internal Battery Management System. The BMS protects against: 1. Under-Voltage – during discharge 2. Over-Voltage – during charge or discharge conditions 3. Over-Current – during discharge 4. Over-Temperature – during charge and discharge 5. Short-Circuit Protection – protects battery cells from damage 6. Single-Cell Equalization

You can connect up to 4 REX batteries, but do ensure you connect them in parallel, not in series.

1) Download the REX app in the Apple Store or Google Play store. 2) Wake up the REX battery, by starting a charge or discharge from the battery. 3) Open Bluetooth connection on your mobile phone, search for Bluetooth Device and find they device with the matching Bluetooth id number on your REX battery. 4) Establish Bluetooth connection and open the REX application on your phone, and connect your phone with your REX battery.

It is recommended to store LiFePO4 batteries at 50% state of charge (SOC). If the batteries are stored for long periods of time, cycle the batteries at least every 6 months. Here’s the storage temperature and humidity range: Less than 1 month of storage: -20℃～35℃， 45%RH～75％RH Less than 3 months storage: -10℃～35℃， 45%RH～75％RH Recommended storage environment: 15℃～35℃，45%RH～75％RH Please do not store the batteries fully discharged. They should be about 50% or higher. They do not require a trickle charger.

You can can download the REX battery APP on your mobile phone and monitor and manage your REX battery. The APP works all types of REX batteries. Alternatively you can create CAN connection and external monitor function to the CAN communication port on the REX battery.

You can connect up to 4 batteries in parallel to increase the capacity. Please note that when connecting batteries in parallel, they must of the same model. Keep the connection wires at the same diameter and length. If your power consumption is expected to increase in the future and you plan to add more batteries, you should start with a larger battery. This would allow you to achieve higher amperage with 4 batteries. For example, if you start with 100Ah, the maximum you can achieve is 400Ah when connecting 4 batteries in parallel. However, if you go with the 200Ah, you can achieve up to 800Ah with 4 batteries. Please avoid connecting lithium batteries in both parallel and series simultaneously.

It is highly recommended. Battery terminals may be covered with a plastic cap will prevent an external short circuit.

n order to charge your lithium batteries from your alternator, you will need a DC-DC charger. The primary purpose of a DC-DC charger is to regulate the voltage and current that come out of your alternator. For any questions, feel free to phone our battery experts or send us an email. We also offer 24/7 chat support to ensure all your questions are addressed!

Yes, you can charge REX lithium batteries with solar panels. Do use a certified solar charge controller that gathers energy from your solar panels, and stores it in your REX batteries. You should size your charge controller based on the voltage and current output of your solar array setup. That will ensure that your charge controller will be able to process and regulate the power coming from your solar panels.

The short answer is no, you would be able to charge your REX battery with any 48V lithium chargers, but we highly recommend to use our specific REX 48V chargers. Most AGM battery chargers are within the 48V range could be compatible with REX lithium batteries. If you have a charger with a lower voltage, it may still charge the battery, but it won’t charge it to 100%. A charger with a higher voltage would not charge the battery and the BMS would enter protection mode due to it’s high voltage disconnect safety feature. Although many AGM battery chargers are compatible with LiFePO4, wet cell or flooded battery chargers are not compatible as they typically charge at a higher voltage. Still unsure of which charger you need? Chat with one of our battery specialists to get you on the right track.

LiFePO4 batteries can safely charge between (0°C to 45°C).

Most lead-acid battery chargers can be used with LiFePO4 batteries as long as they are within the appropriate voltage guidelines. AGM and Gel algorithms typically fall within the LiFePO4 voltage requirements. The voltage for wet cell or flooded battery charging algorithms are often higher than LiFePO4 requirements, which will result in the BMS disconnecting the battery at the end of the charge cycle, and may result in the charger displaying an error code. If this happens, it is generally a good practice to replace your charger. Since the BMS protects the battery, using lead-acid chargers will not damage the battery. However, we still highly recommend to use our REX 48V chargers for a save and long-term operation of your REX battery.

REX LiFePO4 batteries can be discharged up to 100% of their capacity. However, to optimize the performance of your LiFePO4 battery, to achieve a higher cycle life, and to avoid the BMS disconnecting the battery, we recommend limiting the discharge to 10% (off total capacity) . If the BMS disconnects the battery due to low voltage, at 100% depth of discharge, remove the load and recharge the battery to reactivate the BMS.

LiFePO4 batteries can safely discharge between -20°C to 60°C. All REX LiFePO4 batteries come with a built-in BMS that protects the battery from low-temperatures and high-temperatures. If the BMS disconnects due to cold or high temperature, wait until the temperature is more suitable and the BMS will reconnect automatically.