Click on the picture to enlarge and you will see the square "select" black button in the middle of the meter. This button toggles thru its functions. This first picture shows the percent of charge remaining in the batteries. This is the most used function on the meter as you can tell at a glance your battery condition and most of the time I just leave it on this function.
This photo taken at a different time and shows the current voltage of the batteries.
Hard to see the green charging light in the upper left but when lit it show how many amps are flowing into the batteries.
Again a little hard to read (forgot to turn off the flash on the camera) but the red minus light to the left of 01.7 is lit and the meter show 01.7 amps are being used from the batteries. This function is very useful and you can see how many amps every appliance or light is using just by turning them on and reading the meter.
By knowing how many amps are being used from your batteries, you will know how many amps need to be replaced no matter if using a battery charger or solar panels. After all, solar panels are just battery chargers using the sun and not electricity to charge your batteries.