[Kennekam]

I have a 5 year old Raylite AGM as my starter battery and a Varta deep cycle. I use the National Luna (NL) controller to manage the batteries. The car is a Gen 3 DiD

For a while now, I have then strange intermittent behavior. When I try to start the car, the battery acts as though it is flat. I then use the button on the controller to go into winch mode which connects both batteries and the car starts. If I then switch off and start again normally, all is well.

The problem is more evident when I have done a long trip rather than when stop starting in town. I would have expected the opposite.

Looking at the NL display, the battery seems to be flat when it does not want to start, but minutes later it seems fully charged. The second battery seems to stay fully charged most of the time.

Is the problem with the battery, the NL system or the alternator that is not charging?

[Roelf_le_Roux]

Hi Kannekam,

When I started reading and saw a 5 year old battery was involved my first thought was "battery". Your symptoms however do not support a failed battery.

If it was me; I'd undo, clean and redo all the battery and earth connections. I'll also clean the battery surface. I once had a strange behaving battery and my mech showed me the massive current running along the battery surface.

Your symptoms also don't support a failed alternator.

[Lock]

I'm guessing dirty connectors. As soon as you jumps some current trough it works.