Battery dead after sitting almost 3 weeks

[ajholt7]

My boat has 11 hours on it now. Whent out yesterday after sitting for three weeks(in the shop to repair prop and gelcoat)and the battery was dead. Jumped the boat and rode around for about 30 min. Stopped in a bay, (no radio on, nothing electrical) and it was dead again. Get it jumped again, and then it is idleing rough, so I take it out and open it up. Next time I shut it off it restarts, but is slow to turn over. So what do you think? Bad Battery?

[chpthril]

Sounds like something may have been left on or the guys at the shop enjoyed your tunes while they worked. The battery is probably good, just needs to be charged with a battery charger, as the alternator is not designed to recharge a dead battery, especially in a 30 minute period. Needs a good 4+ hrs on a charger.

[ajholt7]

Thanks I will charge it, and probably start my second battery install. Getting jumped sucks.

[dogbert]

Thanks I will charge it, and probably start my second battery install. Getting jumped sucks.

Make sure you use a slow charge and charge it for longer.

[ajholt7]

I am thinking of moving my starting battery and putting my second battery where my starting was. My starting battery is a Group 24. If I use a second group 24 will I regret not getting a 27?

[ajholt7]

I am getting ready to add a second battery. My alternator cable goes to my starter and then to my switch. Do I have to seperate that when I add in the acr? Can I leave it as is and piggy back off of the acr to the switch or will that send to much to the acr when starting? I hope this makes sense. If I have to run a seperate wire can it be 2awg or does it have to be 2/0 on the charging side?

[ajholt7]

I think I have figured out the wiring, but still need to know can I run 2awg from the ACR and 2/0 to the starter? Also does the ACR have to be connected to the key switch?