LiTime Support Center

How to Check:

Use a smartphone camera to detect. Replace the charger to test charging performance.

Further investigation requires a video of the noise to determine if it exceeds 60 decibels (within a 1m open space range).

Possible Causes:

1. Vibration from internal components (e.g., inductors, transformers).

2. Abnormal cooling fan operation due to aging, loosening, or dust.

Solutions:

1. Clean the charger’s cooling vents and ensure the fan is not jammed.

2. Secure loose components (e.g., add a silicone pad for vibration damping).

3. If the noise persists, replace the charger.

When the charger is not working, check the indicator light status:

1. Red light flashing → Battery overvoltage/undervoltage protection.

Solution: Connect a multimeter to measure the battery voltage while charging. Improvement: Discharge the battery first, then recharge using a lower current charger, and adjust the float voltage to 13.5V.

2. Red and green lights flashing alternately → BMS protection state.

Solution: Discharge the battery first, then recharge to activate it.

3. Only green light on, but not charging → Charging recognition fault.

Solution: Replace with a compatible charger.

Main Cause 1: Charger or mode mismatch

1. Explanation: Non-LiFePO4 chargers, or selecting the wrong mode (e.g. lead-acid), will not provide the correct parameters.

2. Solutions: Use a dedicated LiFePO4 charger (14.2–14.6V). Set MPPT/DCDC to LiFePO4 mode (or user-defined with correct parameters).

Main Cause 2: BMS protection activation

1. Explanation: After full charge, the BMS closes charging to protect cells, causing ~0.7V drop. Voltage spikes may repeatedly trigger protection.

2. Solutions: Discharge with a >2A load, then recharge to reset BMS. Reduce float voltage to 13.5V × N (N = number of packs). Adjust charger/MPPT parameters.

Main Cause 3: Insufficient charging time or current

1. Explanation: A 100Ah battery needs ~10h at 10A to fully charge. Insufficient current (e.g. weak solar input) leads to incomplete charging.

2. Solutions: Extend charging time based on capacity & current (100Ah ÷ 10A = 10h). Ensure PV panels provide >12V output and adequate power; upgrade panel if necessary.

Main Cause 4: Battery or connection issue

1. Explanation: If resting voltage <10V, BMS protection blocks charging. Loose/oxidized terminals or undersized cables reduce charging efficiency.

2. Solutions: Use a 0V activation charger or connect PV panel directly to activate. Inspect terminals: clean oxidation, tighten firmly (spring washers flattened). Use ≥35mm² copper cables to reduce voltage drop. Cross-test with another charger/battery to identify faulty equipment.

Cause 1: Unstable current at the input end.

Cause 2: Normal operation of the charger may produce noise, including the sound of the cooling fan starting and the slight clicking sound when the relay switches.

Solutions:

If abnormal noise occurs, troubleshooting tests are required:

1. Test with a different socket (to rule out power grid interference).

2. Power on without a load (without connecting the battery) and observe if there is still a strange noise.

3. Gently shake the charger to check if there is any loose parts.

Causes and Solutions:

1. The charger voltage is too low. For a 12V system, the lithium battery charging voltage should be between 14.2-14.6V.

2. Insufficient charging current. Use a higher power charger or increase the current setting.

We suggest you follow these steps:

1. Disconnect all charging devices, let it sit for 30 minutes, and then restart the DC-DC.

2. Use a multimeter to check the input voltage:

If the voltage is <12V and the red light is flashing, it is recommended to replace the DC-DC.

If the voltage is normal but still abnormal, please check the main battery status.

Quick power recovery:

Charge the main battery to 13.8V through the car ignition.

If the voltage is repeatedly too low, it is recommended to upgrade the generator to an output of more than 100A.

Solutions:

1. Connect the D+ port to the vehicle's ignition switch (key-controlled) or the IN+ port (for continuous power supply).

2. Install a circuit breaker to protect the main battery (select a rated current of 1.3 times the system current).

If further assistance is needed, please provide:

1. DC-DC model.

2. Screenshot of the actual voltage of the main battery.

3. Photos of the wiring during the abnormality.

Possible causes are as follows:

1. Insufficient input voltage.

Solution:

Start the engine to charge the main battery to above 13.8V.

Replace the generator with an output current of ≥100A.

2. Wiring connection issues.

Solution:

Check the voltage of the D+ port. If it is less than 12.5V, connect the ACC line or directly connect to the IN+ port.

Clean and tighten all wiring terminals and replace damaged cables.

3. Abnormal battery status.

Solution:

Disconnect the load and discharge for 30 minutes, then recharge.

Replace with a low-current charger to avoid voltage fluctuations.

4. Device failure or incorrect mode.

Solution:

Long press the Crossover key for 3 seconds to exit the reverse charging mode.

Test with another charger.

Possible Cause:

• On dual-channel models, the reverse charging function may be mistakenly triggered → lights flash together with a buzzing sound.
• On single-channel models, the red fault light will stay on. In this case, test with a different DC-DC unit to confirm performance.

Solutions:

1. Long press the Crossover key for 3 seconds to exit reverse charging mode.
2. Test the system with another charger.

Preventive Measures:

1. Install a circuit breaker between the main battery and the DC-DC (rated at 1.15–1.3 × system current).
2. Regularly check the battery’s resting voltage (should be ≥13.33V when fully charged).

For troubleshooting, please provide:

1. A video showing the flashing light frequency (fast or slow).
2. The input/output voltage values measured with a multimeter.

Cause 1: Insufficient input voltage of the starting battery.

Solution: Use a multimeter to check if the input voltage is within the charger's input voltage range of 12-16V; it is recommended to use it within this voltage range.

Cause 2: Abnormal connection at the input end, the wrong battery is connected.

Solution: Investigate the voltage of the input signal.

1. For DC-DC with MPPT function, is the ACC line connected? The connection of the ACC line determines the input voltage range of the DC-DC charger.

2. Can voltage be measured at the input end? What is the measured voltage? Is the voltage within the range of the DC-DC charger?

Cause 3: Abnormality at the charger's output end.

Solution: Measure the voltage at the output end (the end connected to the house battery); whether it outputs the correct charging voltage (such as in the range of 14.2V to 14.6V).

Cause 4: Abnormality with the house battery itself.

Solution:

1. Disconnect all loads from the house battery and let it sit for more than 30 minutes.

2. Measure the voltage of the battery after it has been sitting to confirm whether it is truly not fully charged.

3. Is the battery abnormal? (For example, if the voltage is abnormally high or low, indicating BMS protection)

Cause 5: The battery is being charged and discharged at the same time.

Solution:

Disconnect high-power loads during charging, only connect the battery, and observe whether the charging voltage and current return to normal.

Possible Causes & Solutions:

1. Charger detection issue

Cause: After completing charging, the charger fails to detect battery discharge.

Solution: Check the recharging voltage setting of the charger, and try reconnecting by powering off and on.

2. Unstable input voltage

Cause: The Input voltage fluctuates abnormally.

Solution:

a. Measure the input voltage of the starting battery.

b. Ensure the starting battery remains ≥12.5V after charging.

c. If the input end has ACC control, confirm that the ACC signal is not interrupted.

3. Input signal issues

Cause: Incorrect or unstable ACC control signal.

Solution:

a. Check the ACC control line is connected correctly.

b. Confirm a stable DC voltage is present at the input end.

c. Ensure the input voltage is within the DC-DC's allowable range.

4. Output or battery end abnormality

Cause: Fault at the output stage or battery side.

Solution:

a. Output check: Measure output voltage, confirm it is within the normal charging range. b. Battery check: Disconnect the battery, let it rest for 30 minutes, then measure resting voltage to verify charge status. Avoid heavy loads during charging (recommend disconnecting high-power loads).

Cause 1: Fluctuations or instability in the input power supply.

Solution: Check if the input voltage from the mains power/ generator/ solar is stable and within the specified range.

Cause 2: Abnormalities at the battery end, with voltage being too low or poor contact.

Solution: Measure the resting battery voltage:

For a 12V system, it should be ≥10.8V;

For a 24V system, it should be ≥21.6V;

For a 48V system, it should be ≥43.2V;

Check if the battery terminals, fuses, and wire connections are secure.

Cause 3: Fluctuations or instability in the PV input.

Solution:

1. Check the voltage and current fluctuations at the PV end;

2. Confirm whether there is shading, low light, or shadows causing power fluctuations;

3. It is recommended to use photovoltaic panels of the same brand/model to reduce mismatch in series and parallel connections.

Cause 4: The load is too large or changes drastically.

Solution:

1. Check if the installation location of the all-in-one machine is well-ventilated.

2. Avoid using it in direct sunlight or in a high-temperature enclosed space;

3. Regularly clean the fan and filter dust to maintain smooth heat dissipation.

4. Check the total power of the actual connected load to confirm whether it exceeds the rated power of the all-in-one machine.

5. Verify whether there are any impact loads (with a starting current of 5 to 10 times the rated).

Cause 5: Excessive heat dissipation or ambient temperature.

Solution:

1. Check if the installation location of the all-in-one machine is well-ventilated;

2. Avoid using it in direct sunlight or in a high-temperature enclosed space;

3. Regularly clean the fan and filter dust to maintain smooth heat dissipation.

Fault Code [01] Battery Undervoltage Protection

Fault Code [02] Battery Average Discharge Current Overcurrent

Fault Code [03] Battery Not Connected Warning

Fault Code [04] Battery Over-Discharge Protection

Fault Code [05] Battery Overcurrent Protection

Fault Code [06] Battery Overvoltage Protection

Fault Code [09] PV Input Overvoltage

Fault Code [13] Bypass Overload

Cause 1: Abnormal DC input voltage

Solution: Measure the voltage at the DC input terminal (confirm the actual value with a multimeter); compare it with the product specification sheet to see if it exceeds the allowable range. Adjust or replace the input device to ensure normal input voltage.

Cause 2: Load exceeds the power capacity

Solution: Confirm all connected loads and their rated power. The total power should not exceed 80%-90% of the rated power of the inverter/charger controller. If exceeded, the loads should be started in batches.

Cause 3: Abnormal PV input terminal

Solution: Measure whether the PV open-circuit voltage is within the allowable range and check if the photovoltaic panel wiring is reasonable.

Cause 4: Short circuit or abnormal surge at the load end

Solution: Disconnect all loads and start the all-in-one machine alone to see if it recovers. Provide a video or picture of the abnormal report.

Cause 1: BMS protection feedback difference

• Explanation: When fully charged, BMS cuts off charging → terminal voltage may appear 0.5–0.7V lower than actual cell voltage (MOSFET voltage drop).
• Phenomenon: Some monitors show BMS-calculated cell voltage (theoretical), not real-time terminal voltage.
• Solution: Disconnect all loads/chargers, let battery rest 30 min, then compare multimeter reading with screen. If caused by BMS, discharge with a >2A load (e.g., light bulb) to reactivate and restore accurate voltage.

Cause 2: Different measurement points

• Explanation: Multimeter measures real-time terminal voltage, while screen data may come from the shunt/BMS with delays or filtering.

Cause 3: Load or charging current interference

• Solution: Inspect wiring and contact resistance. Ensure terminals, shunt, and screen connections are clean and tight. Use ≥35mm² cables to reduce line loss. Calibrate or replace the measuring equipment.

Cause 4: Voltage drop during high-current operation

• Explanation: High discharge current causes instant voltage drop (e.g., 10A → 0.2–0.5V). Multimeter captures instant value, screen shows smoothed average.
• Solution: Calibrate or repair the equipment.

Cause 5: Screen calibration error

• Solution: Re-calibrate voltage offset (refer to user manual).

Cause 6: Multimeter accuracy issue

• Solution: Verify with a high-precision multimeter (e.g., Fluke).

Cause: Abnormal power connection

Solution:

1. Check if all terminal connections are secure.

2. Measure the battery input voltage of the inverter/charger.

Main Cause:

No power input, the inverter input terminal has no voltage, and there is no power supply.

Possible Causes:

1. The fuse is blown or the temporary protection is activated: The internal overcurrent or short-circuit protection circuit of the input terminal is disconnected.

2. The screen connection is loose or has poor contact.

3. The battery is not connected or has a low voltage.

Solutions:

1. Use a multimeter to measure the voltage at the battery input terminal to ensure normal input of 12V/24V/48V, etc.

2. Check that the input wiring is secure and there are no problems.

Cause 1: The battery voltage is too low (<5V), and the device is not activated.

Solution: It needs to be charged separately to activate.

Cause 2: The Bluetooth pairing process is incorrect.

Solution: Delete the device record in the phone's Bluetooth list, and reconnect by scanning through the APP instead of pairing in the system settings.

Cause 3: Interference or too great a distance.

Solution: Use within an interference-free range.

Cause 4: Issues with the phone.

Solution: Ensure the APP has Bluetooth and location permissions, clear the phone's Bluetooth cache (especially for Android) and restart the phone.

Upgrade to the latest version of the APP.

Cause 1: The battery type and charging parameters are set incorrectly.

Solution: Verify the battery type and rated voltage (such as 12V/24V/48V). If it is a lithium battery, set it to "Lithium Mode" and adjust the charging voltage to 14.4V~14.6V (for a 12V system) or refer to the standard parameters in the user manual.

Cause 2: The wiring method is incorrect or loose.

Solution: Check if the wiring sequence is correct (solar panel ➝ controller ➝ battery). Confirm that the positive and negative poles are correctly connected, the wiring is secure, and the terminals are tightly fastened without any virtual connections or loose phenomena.

Cause 3: The solar panel is abnormal.

Solution: Use a multimeter to measure the open-circuit voltage of the solar panel to ensure it meets the minimum voltage requirement for the controller to start charging. If a short circuit is detected, immediately investigate the circuit and repair it.

Cause 4: The battery voltage is too low or there is a short circuit.

Solution: Use a multimeter to measure the current battery voltage. If it is below the protection threshold (such as <10V), try pre-charging or replacing the battery.

Cause 5: The controller displays a fault code.

Solution: Check the fault code on the controller's display screen or in the APP, and take corresponding actions according to the user manual (such as adjusting the wiring, recovering from over-temperature status, or restarting the device).

Cause 6: The battery terminals are not tightened or the polarity is reversed.

Solution: Check if the positive and negative poles of the battery are correctly connected and if the terminals are tightened without any looseness or oxidation. If reversed, immediately correct it after disconnecting the power.

Cause 1: The battery is not connected, or the wiring is loose.

Solution: Connect the battery end first (with the correct positive and negative poles), and then connect the solar panel.

Cause 2: The battery voltage is too low or the polarity is reversed.

Solution: Measure the battery voltage, confirm the positive and negative poles, and if necessary, replace the battery or activate it through external voltage boosting.

Cause 3: The display module is faulty, but the controller itself is working.

Solution: Connect to the Bluetooth APP to read the data and confirm whether the controller is still working.

Cause 1: The load type and power are not matched.

Solution: Confirm the load type (such as lighting fixtures, motors, etc.) and power. It is recommended that the load power be lower than 80% of the controller's rated output power. If the load is an inductive load (such as a pump/motor), please connect it directly to the battery.

Cause 2: The load current limit is exceeded.

Solution: Use a clamp meter to measure the load current to ensure that the actual working current is ≤ the controller's rated current (such as 20A). If exceeded, please replace with a higher specification controller or change to direct battery connection.

Cause 3: The load mode is set improperly.

Solution: Check the load working mode of the controller and set it to "manual mode" or the appropriate light control + time control combination mode according to the requirements to ensure that the load is powered as needed.

Cause 4: The battery is abnormal or in a protection state.

Solution: Check if the battery voltage is normal (such as a 12V lithium battery ≥ 10V). If the battery is in a protection state, please activate the battery first.

Cause 5: The battery wiring is loose or the polarity is reversed.

Solution: Check if the battery wiring terminals are tightened and if the positive and negative poles are reversed. Ensure that the wiring is correct and secure. It is recommended to rewire for testing if conditions permit.

1. Weak Light

Cause: When the light intensity is insufficient, the output voltage of the solar cell may fluctuate near the minimum threshold voltage for MPPT to start. When the voltage is below the threshold, MPPT will stop working. When the light temporarily strengthens and the voltage rises, MPPT will restart, forming an intermittent cycle.

Impact: MPPT frequently starts and stops, and cannot continuously track the maximum power point.

2. Temperature Protection

Cause: High or low temperatures may trigger the temperature protection mechanism of MPPT or the battery system. For example, when the temperature is high, the equipment will automatically reduce the load or shut down to dissipate heat, and then restart when the temperature returns to normal.

Impact: The protection mechanism causes MPPT to pause and resume periodically.

3. Battery Charging and Discharging at the Same Time

Cause: If the battery supplies power to the load while charging (charging and discharging at the same time), or if the battery repeatedly switches between full and not full states, the battery management system (BMS) will adjust the charging strategy (such as switching between constant voltage and constant current modes). MPPT needs to frequently respond to these changes, resulting in unstable operation.

Impact: MPPT needs to continuously adjust the output power, causing intermittent operation.

4. Wiring Issues

Cause: Poor contact of the wiring, high impedance, or wiring errors can lead to unstable voltage/current signals. MPPT may misjudge the state of the photovoltaic array (such as thinking that the light has suddenly changed), thus repeatedly switching working modes.

Impact: Signal interference directly destroys the continuous tracking ability of MPPT.

1. Recommended to use Gmail, Yahoo, Microsoft, and some other public domain mail service providers' mailboxes (note that it is recommended, not required), the reason is that some enterprise mailbox service providers may have some security settings, resulting in the rejection of our mail.

2. If you don't check the incoming mail, please check whether it has been moved to spam mail.

APP version is below v1.2.4, please check whether there are spaces before and after inputting email and delete the spaces before trying again.

After registering the account, the APP can remember the devices added by the user under the condition of a network. Guarantee that the subsequent switch to cell phone use can be convenient to synchronize all the devices in the account, without having to add the device again.

In order to protect the user's account security, such as logging in for a long time in the absence of network environment to use or did not use the APP, the next time in the network environment to use, the APP will ask to re-login after use, and the APP defines that this login effective period is generally 30 days. It means that you can use device management (add, connect, view device information, etc.) without logging in again within 30 days after the first login and open the APP.

The device uses a low-power Bluetooth module with a Bluetooth connection distance of about 10 meters.

Rest assured, the warranty will take effect automatically from the date of purchase, and no additional activation is required.

If you need any assistance, you can contact us directly with your order number to help resolve any issues.

You can directly contact the seller's service email to obtain support, or you can reach out to the warranty support team using the information provided on the product or in the instruction manual.

The return label we provide is prepaid and valid. If the logistics company reports that the label is unusable, please contact us directly and we will provide it again or arrange a pick-up service to your address.

We guess it might be related to the network or device. I recommend trying to download it on another computer if possible.

If you still face difficulties, please reach out to us through the information provided in the packaging or instruction manual, and we will assist you further to ensure you receive the prepaid return label.

If you don't have the original box, it is ok to find another suitable box to pack the battery, or we can help send you a new empty box.

I understand that not having a printer can be inconvenient. I suggest checking with a neighbor or visiting a nearby stationery store, as they often offer printing services.

Since our batteries and chargers were shipped with different packages, it is possible that they arrived at your address at different times.

It is recommended to purchase our product directly on our official website www.litime.com or from our Amazon Store, or eBay. If you have placed an order from fake websites, such as Facebook, please file a dispute with your banking institution to get your money back. With the help of our excellent customers who have reported several of these fake websites, we have been able to remove them, and our legal team will continue to monitor and take further actions to prevent them from reappearing.

Please email us your tax exemption certificate as well as the order number to support@litime.com and allow our finance team at least one business day to review your document. If your document has met the necessary requirements, you will be notified of approval to proceed with your order.

Please note that it is only for LiTime website orders. For Amazon orders, please contact Amazon directly, as we do not have the right to refund the tax.

During promotions on our website, automatic discounts will be displayed on your checkout page. Alternatively, you can redeem your membership points for a discount code. Simply click to copy the generated code, then paste it into the promo code field at checkout—the system will deduct the amount automatically before payment is completed.

Please note that only one coupon code may be applied to an order, you cannot combine multiple coupon codes for additional discounts. Coupon codes are only valid on our official website.

We appreciate your service and are always looking for ways to support our customers. We're offering all verified members of the Military & Military Families, Veterans an 8% OFF exclusive discount. (Please note that discounts cannot be combined and only one discount may be applied to each order.) You may confirm your status through the link to take advantage of this special offer.

Yes, we do offer a price adjustment within the 30-day purchase period under these circumstances:

1. Price match only applies to sales and discounts price adjustment on our website.

2. Cannot be applied towards third-party limited sales events, such as Amazon Prime Day, eBay sales promotions.

3. Only one coupon code may be applied to an order; multiple coupon codes may not be combined for additional discounts.