Some useful information about 12V battery systems
12V Batteries
Guide to 12 volt rechargeable batteries
Overview of the types of 12 volt batteries most commonly used for recreational vehicles and camping
Estimating state of charge from battery voltage
Discussion of how to estimate state of charge for AGM and LiFePO4 (lithium) batteries
Charging lead-acid batteries
How to properly charge and look after your lead-acid batteries
Electricity
Common Electrical Terms
A simple explanation of some of the most often used battery and solar panel jargon