Battery warning light question

[stroke this]

my 06 PSD has been sitting for a while and when i turn key to on to let the glow plugs cycle i cant remember if the battery warning light is supposed to stay lit on the dash. it goes away as soon as the engine starts up. It has been on a trickle charger while sitting and cranks just fine. Am i just stupid and that is the way it is or should i investigate further?
thanks
scott

[kensois@msn.com]

It should stay on until it starts being charged by the alternator.

[stroke this]

thanks