Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
I have a 1978 Catalina 25. I am going to replace the wires going from the panel to the battery as they look very worn and corroded. Any tips on figuring out the wiring would be helpful as well.
Your batteries should fit in the amount of space where they'll be kept and they should be Deep Cycle Marine Batteries, not starter batteries. Deep Cycle batteries can tolerate repeated discharge and recharge much better than starter batteries, and that's the way you'll use them. Also, deep cycle batteries have way more cold cranking amps than you'll ever need for a small outboard motor. Starter batteries are needed for big motors. My C&C 35 has a 32 hp diesel engine, and deep cycle batteries have plenty of starting power for it.
If you haven't used it yet, they'll probably let you exchange it, especially if you're going to buy another one.
Steve Milby J/24 "Captiva Wind" previously C&C 35, Cal 25, C25 TR/FK, C22 Past Commodore
My jury is still out. I needed to replace a second battery last year and Autozone was the closest place. Your link shows a deep cycle battery. I have the same deep cycle battery, but it only has 2 seasons on it. I used to use Walmart batteries until they quietly changed manufacturers and specs. Autozone's are Johnson Controls batteries, a pretty reliable manufacturer, they make Optimas, but I'll pass judgement in a few years.
edit: I clicked the link again and it took me to a marine starting battery. Exchange it if it doesn't say deep cycle on the side. It shouldn't be a problem at AutoZone.
Dave B. aboard Pearl 1982 TR/SK/Trad. #3399 Lake Erie/Florida Panhandle
Odd that the photo shows a starting battery yet the features say yes to deep cycle Cranking Amps (CA): 1000 Deep Cycle: Yes possibly the DP in the model # 27DP-DL stands for Duel Purpose?
Scott-"IMPULSE"87'C25/SR/WK/Din.#5688 Sailing out of Glen Cove,L.I Sound
Dual purpose simply means that the batteries can be used for both deep cycle and starting your engine. It also implies a compromise between the characteristics of both. Deep cycle batteries are designed to produce lower current over longer durations and to survive recharging once they are deeply discharged. Never discharge beyond 50% of capacity, and Always, always, always recharge your battery ASAP once you're back to a power source. From the picture and specs, it looks like it should be a good quality 90AH group 27 battery. I've used Autozone batteries in my cars for years. The price is about on par with other non-boating shop prices. A bigger issue is how's your wiring? First things first, you should replace the cable from the battery to the power panel with #10 stranded electrical cable. You should install a main 30-40A fuse right at the battery to prevent dangerous short circuits which can lead to a boat fire which could destroy your boat. Do you have an electric starter on your engine? If so, you'd need to replace the wire with #6 cable and add a 50-60A fuse at the battery end. If not, you can probably use #10 or 12 wire from the alternator charging circuit if you have one. Again, a 10-20A fuse is an essential. The internal wiring of the boat should be inspected. Three main areas are cabin lighting, mast lighting and navigation lighting. Note that the negative wire for the house lighting also serves the navigation bow red-green light. I replaced this on Passage with a home run for both the positive and negative wires. #12 stranded cable. Other 12 VDC circuits include your VHF radio, any entertainment systems, deck lighting, chart plotters, speed and depth instruments and inverters. If you have a 30A 120VAC circuit for shore power aboard, any modifications to that requires an electrician for safety. If you have questions about what 12 VDC wire gauge you need for a specific purpose, distance, amperage, Don Casey has it well described in his book "Sailboat Electrics"
Bruce Ross Passage ~ SR-FK ~ C25 #5032 Port Captain — Milford, CT
I like the BlueSea fuse block but you can also use a 30A inline fuse holder such as the one shown here. https://www.amazon.com/gp/product/B01DYPY0E4 I bought the heaviest-duty fuse holder I could find at Auto Zone. I spliced it inline. I put a ring spade lug connector on one end and crimp connected it to the cable feeding the panel on the other. It handles a 30A fuse. For my engine, I bought a conventional fuse holder that would accommodate a 60A fuse. I mounted it to the inside of the battery area under the quarterberth next to the battery compartment.
Bruce Ross Passage ~ SR-FK ~ C25 #5032 Port Captain — Milford, CT
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.