Battery Replacement

[Joe]

I have a Catalina 30 and am at about the point where I need to replace old batteries with new. My question to the forum is relative to your experience with battery replacement. Overall, is a deep cycle marine battery basically the same from one to the other when looking at the wet cell types? I need a 90 amp hour battery for replacement and I've seen the ones that West Marine sells that are about $90. But, I've also seen the 90 amp hour deep cycle marine batteries made for Johnson Controls at Costco for $45. When you need to buy 2 batteries and you see what looks like the same battery for 1/2 price, you begin to wonder. I'd like to hear about other's experiences relative to battery replacements they've done, the overall battery life they've seen and their thoughts on shopping for new wet cell battery replacements.

 

[Todd Osborne C30 Windwalker]

They seem the same to me

Lead-Acid batteries are actually very low tech, and the only discernable quality difference (that I know of) is the thickness of the lead plates in the battery. Deep Cycle batteries have thicker plates and can handle more charging cycles which over time dissolves the plates. the downside to this is the immediately available electricity is limited, measured by cranking amps. The thinner plates allow more surface area to be in contact with the acid facilitating a quicker chemical reaction. Other than engine starts, most sailors prefer the longer life of the deep cycle batteries. I personally use the Costco deep cycle batteries myself, but have heard of others wanting more than 100 Amp Hours, using golf cart batteries doubled up (as each are 6 volt) and are significantly cheaper than the bigger marine deep cycle batts.

 

[Rico]

more on batteries

Not needing cranking amps for my purposes, I use, and have had excellent luck with golf cart batteries. More on this in the archives (After 7/6, phrase "Apples and oranges"). Like Todd, I have found golf cart batt's very reccomendable. Proper maintenance is the key. --Rico

 

[Mark Gale]

Dual

I screwed around with batteries last spring and had a couple change-outs before I got it right. I ended up with West Marine dual purpose batteries... the most powerful dual purpose they make without going to those huge, oversized monsters. I have been extremely happy. Lake Michigan is always cold and the air is cool at either end of the season, so I wanted something to crank that MX25 diesel. It pops off right away on one battery. We can also run things for a long time without significantly losing charge. We run the CD player, an inverter to charge my son's remote control boat, a light or two... then can use the same battery to crank the engine. We are conservative with power, but dual purpose works well for me.Long periods at anchor or overnight stints with lights and autohelm might call for the deep cycle option. I found, however, that they had trouble starting the engine. We always sail on one and keep the other as reserve and can always start the engine to recharge on a day-long or overnight run.