Dead battery, or dead alternator?
 

My 07 MT had been starting hard for a couple of days, with the battery starting to struggle just before it would start, and the interior lights would flicker too. Finally, today I went to start it up this morning, and the battery turned the engine a few times and gave up the ghost. The interior lights were still on, but with the starter engaged, went very dim. I didn't leave anything on overnight, but it ran just fine when the battery was getting weak.

So, is the problem with the battery itself, or is the battery just not getting charged because the alternator is bad? Is there any test I can do to check, or any indication that the alternator would have gone out? Thanks.

most likely it is your battery.

yep battery is 4 yrs old . just buy a new one and don't piss about :)

Damn. All right, new Optima Redtop on the way. There goes $150.

Easy way to tell is....

If it starts and runs with a boost after the boost is disconnected...it is the battery..

If it starts and runs with a boost...but when the boost is removed it stalls...could be the alternator ;)

After you replace the battery, check the charging system.