We recently received more and more questions regarding the use of lead-acid batteries. Due to modern avionics and their high energy consumtion lead-acid batteries often work on their limit. Service-Info 102-2018 explains the correct handling of lead-acid batteries and gives advice how to choose the correct battery in order to perform very long flights.
Here is the direct link: Service Info 102-2018. (Note: English text at the end of the document)