Lead acid batteries have a limited lifespan and loose capacity over time. Not charging correctly, repeatedly deep discharging, storing batteries uncharged etc. will shorten the lifespan drastically. It is also important to keep the battery top clean.

Read more about battery maintenance

• Check battery voltage for each battery separately when fully charged. Fully charged the total open circuit voltage should be above 12.6 V (2.1 V per cell).
  • A fully charged battery voltage around 10 V indicates a dead cell and battery needs replacement
• Check condition of the battery poles and connectors. They should be kept clean for good electrical conduction.
• Check that the 3 battery cables are not damaged