Good morning,
My Disco 2 is losing voltage as soon as I park. It starts at 12.8, goes down to 12.7 in 5 minutes and then .1 volt every hour. After 24 hours it stands at 12.4 which makes it a struggle to start the vehicle. I have taken it for a Diagnostic test and no fault codes where displayed. And suggestions as to what can cause this please?

 

12.4 is a good resting voltage for a battery. Should not have any trouble at that voltage. It drops after being shut off because it is not being actively charged by the alternator, not because of a drain on the system.

If you are having hard starting I would first get your battery tested to make sure it's putting out enough amperage. Auto parts stores will do this for free.

If your battery checks out, then your starter may be getting tired. More likely to be your battery though I'd say, even though your voltage is correct.

 

Dear Alex,
Thank you for the answer. I had the battery tested at 2 different locations and it tested Sate of Health 90% and State of Charge 100%. I thought the Diagnostics would pick up if starter is faulty? but I will test the starter. Thank you very much.

 

Sorry if this is very basic, but have you removed, checked, and cleaned the cables? Specifically the grounds on the - side and the alt/starter on the + side... and then be sure to check the starter ground itself.

You're looking to tighten, clean, inspect for defects.

 

Log the same hourly voltage tests with the battery disconnected since parked to confirm the drop is from consumption or internal to the battery.

 

Dear Dave,
We will definitely do as you advised above. Thank you very much.

 

Very good idea!!! Will also try this! Thank you very much.

 

@BibiLuka I would be suspicious of the battery, Mine dropped to 11.6 I had a bad OBD Adaptor. My disco still turned over strong and started, quickly at that voltage. Cranking amps really matter

 

Dear Richard,
Thank you very much for the advise. The battery was tested more that once and the resting voltage was still 12.6 V. I actually discovered the fault while busy following advise from another member. The clamp on the positive (red) side was faulty and did not close properly when tightened. We replaced the clamp and now the vehicle is starting like a dream again. Thank you very much for the reply.

 

@BibiLuka good hear and thanks for posting your solution