Ask Rider to remove the battery, check the contacts, re-install the battery
Ask Rider to try to turn on the battery outside the bike – if it turns on externally, the battery itself is probably functional; always turn off before re-installation
Ask to clean any contamination on the battery connectors with a dry brush or compressed air
Ask to inspect all terminals for any physical damage and signs of corrosion
If the charge port is undamaged, clean and dry, ask the Rider to connect the battery to the charger for about 30 seconds. If the battery has an error, the charger LED would flash red which can indicate a battery issue; Vado/Como Gen1 battery LEDs are not capable of showing error patterns.
Note: Make sure charging is attempted within the accepted cell temperature range. Charging is not possible, if cell temperature is below 0 °C / 32 °F or above 50 °C / 122 °F.