E211 speedo pointer

[frankingib]

Hi all. New here. See if you can help me. My W211 E240 speedo pointer goes wild if I don't use my car for a while & then sorts itself out gradually as I drive until it matches lcd speed reading. Has anyone come across this?

 

[Dieselman]

Battery voltage is low.

 

[frankingib]

Thanks for your post. The battery is only about six months old and my Merc sleeps in the garage with a pulse charger. Cranks well and no services gets switched off.