'96 2.2l cav battery replacement issue

Ok so 3 days ago I was leaving work and it wouldn't start. So a co-worker gave me a boost and it got me home. The abs light and emerg brake lights stayed lit on the dash but it still ran. The next day I tried giving it a boost from my grand prix and it just wouldn't take. I went out yesterday, got a new one and replaced it myself, something I have done before. Now when I go to start it I have to hold the key down longer than I used to for it to catch. It would only start up quickly if I have just turned the engine off. Any ideas as to why it's being so difficult?

Thanks.

the alternator might be going out. it might not be charging the battery as much as it should, which would cause an older battery to go out faster, but a newer battery can probably handle it for a little bit

thanks for the response, I appreciate it. I dropped off the car at my regular shop this morning and mentioned everything to them. They just called me and said they checked everything and ran diagnostics and found nothing wrong. Nothing with the alternator,chargning system, battery, ignition, nothing. They did notice the extended or delayed crank, but not why. any other ideas?

Bad ground possibly somewhere.