W216 CL500 battery failure?

[DB7 pilot]

I have an 08 CL500 and after trickle charging the starter battery there seems enough power for all the consumer electronics & that the starter should at least click or attempt to turn over but nothing. Is there a reset that anyone's aware of? I have Keyless Go on this car and I know about the consumer battery in the boot. Any help's appreciated.

[DB7 pilot]

Jump starting worked a treat & got battery replaced under warranty which helped as battery was unique to Merc at £135.00. Thanks for your help.