What issues can a failing battery cause?

So i have been on other forums researching and talking about an issue with my 95 SuperSport.

The main question is if my main battery (cranking, ignition, and all other engine components) battery is failing what all issues would it cause?

I had this hesitation with fuel pressure dropping from normal to low teens and twenties. I have replaced all the pumps, plugs, wires, rotor button, dist cap, etc etc.

So last night I noticed that whenever I turned on any pumps, lights etc my volts started dropping below 10 and everything would cycle on and off. Could a failing battery cause issues with fuel pumps and RPMs at WOT and acceleration?

The battery's a possibility, as is the alternator, but sounds more like bad or corroded connections. I would start with cleaning up all your connections at the battery and alternator. You can also check voltage with engine off/on. Off, you should be up at 12, and running more like 14.

I would also throw a shore charger on your battery, and make sure its topped off before your next time out, or pull it and have it load tested at an auto-parts store. If you ran your battery down a ways at some point, you may just never have gotten it back up to full voltage, which could cause all sorts of problems.

Low voltage can cause a whole host if problems. Things like ECMs and amps can shut down due to low voltage, things like pumps and blowers will run slower and lights can dim. A bad or failing battery will be easy to check and confirm. They are typically either good, going bad as in not able to reach and maintain a full charge, or just plain took a chit. No intermittent in there. As Tom pointed out, dont overlook the alternator. A weak or bad alt will leave a battery undercharged. A bad connection or corroded connection can come and go though. Its effects can change with temp, load, vibration/movement, etc.

low voltage=higher hear=bad for electronics

Thanks for all the info. The battery test seemed good. My alt belt was a little loose and while tighten it the housing broke around the bolt. I guess I tightened it to much or it was just failing. It was the original alt manufactured in 94. I just ordered another one, so we shall see.

Sounds like a battery was the easy thing to identify as the culprit but most likely like others have said it's a alternator. Battery's for the most part if they are somewhat new 3 years or less are pretty bullet proof.

What can happen is roteen Undercharging running a battery DEAD over and over can cause it to Go bad. But if they are charged and discharged with in reason some battery's last for years.

A quick way to tell if your alternator is bad is turn on the key and the shaft that holds your alternator pulley ahold become magnetized. If not then that's the first sign your alternator is bad. With your boat running you should be pushing 13+ volts at the battery. All systems are diffrent but you need at least 13volts or higher to charge a 12v battery