Two questions and they may be related.
I have a 2004 Honday Civic.
1. The car doesn’t seem doesn’t seem to start as readily as it used to. I have to hold the key longer to start it. Is it mstly likely a battery issue or a spark plug issue. Still has its very first battery.
2. The “cigarette lighter,” though it doesn’t actually have the lighter, won’t put out the energy to run a small air compressor that hooks into it. Could it be a battery issue?
Seems like you know the answers to your questions. You could have the battery tested, or you could just accept the reality that your battery is getting old. I don’t know where you live, but if it is in cold country, then you are ready for a new battery pretty soon, before next Winter, so start looking for deals now.
As for the spark plugs, what does your factory service manual say?
These are both routine maintenance items, so it should not be too hard to decide to replace them.