Charger Troubleshooting
The Charger LED is Stuck Flashing Red and Green
The Charger LED is Stuck Flashing Red and Green (LiFePO4)
Situation
The lithium (LiFePO4) batteries do not have enough power to move the cart.
Common Cause
Lithium (LiFePO4) batteries contain a protection circuit that protects the battery against damage from full depletion, as well as overcharging and other things that could damage the batteries.
This scenario is common, especially in carts that haven’t been charged for a prolonged period or have been completely drained. In such cases, a standard lithium golf cart charger is unable to initiate the charging process due to the batteries being “asleep.”
How to Confirm
- Check Voltage: Use a multimeter to check the voltage over the entire battery pack.
- If your pack voltage is testing below 2.0V per cell, the battery is likely in sleep mode or damaged.
- BMS Reset: If the battery has a built-in BMS, try resetting it according to the manufacturer’s instructions.
How To Fix
Option 1: Jump Start with a Fully Charged Battery
- Get a fully charged lithium battery of the same voltage
- Connect the positive and negative terminals of the good battery to the matching terminals of the dead battery using jumper cables.
- Let the batteries stay connected for 1–5 minutes.
- Disconnect the cables, then plug your smart charger into the depleted battery to begin charging.
Option 2: Use a Regulated Power Supply or Manual Charger
- Use a DC power supply or manual charger set to the battery’s rated voltage (e.g., 12V) and a low current (1–2 amps).
- Connect the power source to the battery for a few minutes.
- Once the voltage reaches a safe level, switch to your smart charger to continue charging normally.
⚠️ Always monitor closely—manual chargers won’t shut off automatically.
The following video walks through some ways to wake up a battery that is in sleep mode.
