Yes the boat will still need a battery. The alternator is used to recharge the batteries. So when the batteries are ran down by starting it or using the troll motor, the alternator only charges them back up so you don't have to.
you need the alternator to charge the battery with no alternator when the battery drops to about 10 volts car will not run at all.
As long as the battery is fully charged it will start no matter the condition of the alternator. Eventually the battery will run down if the alternator is not keeping it charged.
Only if the old battery is defective
Generally, no. If you ran the car after the alternator died (which runs down the battery), you may need to trickle-charge the battery for a half-hour or so to bring it back up to a full charge, but most of the time the battery will not need to be replaced.
Alternator is sending to much volts to battery. Suppose to turn itself off when battery gets to around 13 volts. May need new alternator.
Charge and load test battery- it may be not able to take a charge and need to be replaced You may a have blown fuseable link preventing alternator from charging battery
If the alternator is good and the battery does not charge, then the battery may be bad. There could be problem with the electronics. You will need to take it to a place where they sell batteries. They have equipment to check out the battery and the wiring.
Alternator on a car is for re cahrging the battery. So you can have a starter motor without a alternator but you wont get far down the road when the battery runs out of power and the car will die.
A new battery or one that tested good is in the vehicle and the car is still losing power. the alternator is what charges the battery while the vehicle is operating.
If the alternator is not working the battery gets discharged. In most cars a light will show on the dashboard - battery light icon, and this will suggest fault in the battery or alternator. You will need to start the car and check if it is charging the battery, and most garages will do this check for you
your alternator is not charging your battery..u need to get a new alternator
Alternator is sending to much volts to battery. Suppose to turn itself off when battery gets to around 13 volts. May need new alternator.