2012 D4 Crank Battery Dead after Traxide Upgrade

[dannyboydownunder]

Hi - I have a 2012 D4 still with original Crank Battery which I recently upgraded to the Traxide SC80 system - the Traxide configuration includes both a new Optima Battery under the bonnet as well as an old 120ah AGM battery in a box in the boot which can be removed - the problem I am having is that the cranking battery is running flat after just a few days of not using the vehicle - I am thinking that the Crank Battery has died and needs replacement but does anyone have any suggestions on how I can troubleshoot to determine exactly what is causing the problem - note the 120ah AGM battery in the boot is about 8 years old and has been run flat a few times over the years so it is possible that this battery has been damaged - thanks for any advice or guidance!

[Graeme]

I would disconnect the other 2 batteries then see if the cranking battery still wont hold charge.

6-7 years out of an original battery in a D4 is an unusually long run so likely that the cooler weather is showing-up its inability to take adequate charge.

[drivesafe]

Hi Danny, as Graeme suggested, simply disconnect the negatives of both auxiliary batteries and see how your cranking battery goes.

With everything connected up, the SC80 is allowing the two auxiliary batteries to carry your cranking battery.

If your cranking battery is stuffed, then by disconnecting the two auxiliary battery negs, my guess is that your cranking battery will go flat very quickly.

[justinc]

...8 years is about 2 years past the average life of these batteries...
I would say the SC80 has been carrying the cranking battery , not "causing its death"...🙄