Common vehicle issues that may create drain on the battery or cause poor starting performance
1. If the vehicle charging system is not working properly the battery may be discharged while riding. Using a volt meter check that the charging system output voltage is between 13.1V and 14.8V throughout the typical rev range. At 2000 rpm there should be a minimum reading of 13.8V. Please see this video on how to test your charging system.
2. If the bike sits for long periods of time it can drain the battery due to the load created by vehicle systems such as: clock, computer, or alarm systems. Make sure that no accessories have been installed which draw constant power during key off. Some GPS navigation will draw power even with Key Off. Most alarm systems typically draw current when the key is off. If your vehicle has accessories such as onboard GPS navigation or an alarm system, be aware that these vehicles may need to be put on a frequent "routine manual charge" maintenance schedule (see "long term storage" section on the battery charging page). Please see this video on how to test parasitic current draw.
Shorai Batteries produced since mid 2022 contain the Shorai Sentry BMS System. If battery voltage falls too low, the main terminals are electronically disconnected (locked) to prevent a damaging "too deep" discharge. If your Shorai battery is equipped with the Sentry BMS, either of the two scenarios above can cause the BMS to engage (lock) the terminals of your battery. In this case checking the voltage at the main terminals will show zero volts. Attempting to charge with a "smart" battery charger may not work, as the charger will see zero volts and refuse to start. Please note, this is an indication of a problem, not a fault in the battery.
If you have determined that the BMS has been locked due to either condition above, the BMS can be unlocked (reset) in several ways:
- Use the Shorai BMS01 Charger in CHARGE MODE (not store mode). The BMS01 LEDs will alternate between yellow and green for a period while the charger re-conditions the battery. The charger will automatically switch to full 2a charge mode and only the green LED will flash. When the charge is completed, the charger will turn off OR both green and yellow LEDs will go solid ON to indicate the charger is now in READY mode.
- Using a DC power source, apply a low current "jump" of less than 1 amp of 12V~15V to the main terminals for no more than 5 minutes. Disconnect the power supply and test the voltage at the terminals. If it is reading a steady voltage greater than 12.2v you may connect your lithium appropriate battery charger and recharge the battery fully.
- A "jump" from one 12V battery to the Shorai battery for no more than 30 seconds (best to use another motorcycle battery rather than a car battery). Disconnect the jump battery and test the voltage at the terminals, if it is reading a steady voltage greater than 12.2v you may connect your lithium appropriate battery charger and recharge the battery fully.
- Use an old 12v "dumb" charger. If charger output is more than 2A only, use it to unlock the BMS, (until measured voltage is above 12.2v) then shift to an appropriate charger for LiFePO4 Lithium.
- Use a charger with a BMS recovery function such as the Optimate Lithium 4S TM-471.
If you ride twice a month or more, there is usually no need to ever charge for most motorcycles. If you have a vintage or off-road vehicle which has NO draw on the battery when the key is OFF, then you should only need to recharge your Shorai™ battery every few months. However, most modern street bikes have a drain on the battery even when the key is off to support a clock, computer, alarms, GPS nav, or other devices. This draw will eventually drain the battery, which is damaging to the battery and could void your warranty so we recommend a routine charging schedule to top off the battery when not riding.
If you are NOT riding for an extended time (seasonal storage), we suggest setting up a "manual storage" routine as outlined in our Battery Charging page under the "Long Term Storage" section.