Just been out to the shed to see what has been written on wall for years and it definitely says 12.4 is half cooked mate
Spruce might be along shortly 😆
This is the chart we have always used;
https://www.campingandcaravanningclub.co.uk/helpandadvice/technicalhelp/datasheets/guide-leisure-batteries/page6/Rich is pefectly right using this chart and its the chart I use as it makes sense to me and fits in with my charger, daily useage and charge left when the day is done.
And I bet this chart also fits in with Rich's meters he had to keep a track of his daily current draw and solar recharge rate a year or so ago.
However, there is an new chart I just started to see which gives some very strange values. It seems to be cropping up all over the place.
https://www.ukcampsite.co.uk/articles/view.asp?id=722If we went by this chart then I believe we are in trouble.
Most peoples voltmeter is never going to read voltages to the second decimal point acurately. How can there be such a difference between 12.4v signalling 50% charged and the other chart showing the same capacity at 12.06v.
Even after an all night charge and a run the next day, my leisure battery has never read more than 12.8v after a few hours total rest. Its usually 12.7 overnight and a higher alternator charge voltage of 14.6v crambs a little more in.
Our daily usage and the voltmeter at the end of the day make sense with the first chart. If I had to apply the voltages of the second chart, my battery charge capacity just doesn't seem to add up. It the same as you telling me that you have a 1000 liter IBC tank full of water (1000 liters). You tell me that you have taken 400 liters out of the tank but you still have 800 liters left.
https://www.ukcampsite.co.uk/articles/view.asp?id=722Is the first chart under no load conditions and the second chart under load? Our Spring and Varistream controllers cut out at 10.5v under load which identifies the battery is flat at that voltage.