How do I know when the battery has reached end-of-life?

There are 2 measures to indicate batteries have reached their end-of-life state: either 3 years have elapsed since you started using the battery, or when the performance degrades considerably, indicating that the maximum number of charging cycles for the battery has been reached. In both cases, we recommend the purchase of a replacement battery. The price of our batteries is probably amongst the lowest in the industry. Please contact us for details.