New Battery Time

[PW]

The deep-cycle battery that starts the '95 Mercruiser 5.7L (GM) TBI EFI in my direct-drive inboard tournament tow boat has been sluggish of late and finally crapped out yesterday. I've always bought deep-cycle batteries, but then I read the diff between those and a marine starting battery. My ski boat that is constantly being stopped and restarted as we cut the engine every time we pick up a skier and restart to pull the next. Run time between these events is less than 10 minutes. So which battery? Or does it matter? Many thanks for your help, PW

 

[ThomW]

In a nut shell, a deep cycle battery is meant to be drained and recharged, drained and recharged.... A cranking battery is meant for starting boats. Deep cycles are good if you are stopping the boat, but keep the radio playing while on anchor or other things. If you are towing people, and constantly starting the boat, without ever sitting idle too long while using the battery for other things, a cranking would be fine for you.

 

[PW]

Thanks, Tom. Appreciate the help. We don't even play the radio, and hanging out for long periods is done on the pontoon boat. I'll get a starting battery

 

[PW]

Now I just encountered the debate between maintenance-free and conventional or "low-maintenance." Old-school dudes (I'm 61) say there's no-place on boats for maintenance-free batteries. They want to poke a hydrometer in there and top-off the cells. I've been using maintenance-free in my land vehicles for years with no problems. Is there something different for MY marine application that warrants using a conventional battery? I live on an inland lake, so I run in fresh water. My ski season runs from June through mid-September, running the boat for early morning skiing 2 or 3 times a week. I probably only put 10 hours a year on it, if that. The boat gets winterized, shrinkwrapped and stored outside over our cold Michigan winters. The battery goes in the garage where the temp never reaches freezing, I put it on a maintenance charger until the next season. Any advice is greatly appreciated.

 

[Silverbullet555]

I use all maintenance free. In the cars, I find less corrosive build up. In the boat, it just makes sense. I can't justify the cost of AGM over lead acid, so to me it's a nice compromise.

I like batteries by East Penn. You can find them under the Deka brand. Also, under Duracell labels at batteries plus bulbs. My last set lasted 6 years in the boat. I use group 31, but they also make in a group 27 as well a others.

 

[PW]

Thanks, James.

 

[bruceb58]

There's no such thing as a maintenance free flooded lead acid battery. You may not think it has caps but they are there.

You can't use a TRUE Deep Cycle battery for your engine. The good news is that all the "marine" batteries that are called deep cycle are just hybrid batteries and they will work fine.