Starting Battery Location

[Jeff Merrill]

For those who have added a starting battery, where did you put it? Does it fit in with the two existing batteries?Also, any comments on battery combiners (i.e. relays)?Jeff Merrill

[Jon W.]

Does someone know what battery that is pictured?

[Maine Sail]

Starting battery by made by Johnson Controls under the Douglass brand but all group 27's are the same. A starting battery is an emergency back up battery and 99% of the time is NOT used. I always start with my house bank and only select position two for a charge about once every two weeks for a top off of the starting battery and I'm on a mooring. There is absolutely no need for a combiner if you keep your boat at a dock plugged in because the 310 is set up to charge both bakns while on shore power. I don't beleive in combiners, had them, had them fail or cause problems, so I now keep it simple now. NEVER EVER move the battery selection switch while the engine is running it can FRY your alternator in about a nano second if it loses load! Decide which bank you need to charge, usually the house bank, and keep the switch set there. By not using your start battery it is always ready! My house bank is position 1 and 99% of the time that's my selector position and the alternator charges the house bank only.

[Maine Sail]

Quote:"I had discussed with him the option of adding a starter battery on one circuit and putting the two stock 4D's in parallel for the house battery. He asked his instructor for his opinion and the instructor suggested buying a single new 8D and using one of the 4D's as a starter. The 4D's are being used now. I would have to look at the 8D's to compare AmpHours and reserve, etc. It merits some further discussion."One 8D battery (Exide Marine Deep Cycle) weighs roughly 134 pounds and delivers only 200 amp hours while two 4D's weigh 196 pounds combined yet deliver 320 amp hours. 130 amp hours is a lot more punch than 200ah and besides you already have the 4D's. I personally don't like 12V batteries and much prefer 6V batteries in series to create a 12V bank. the ONLY reason I have the 4D's on my boat is because there were brand new and came with the baot and I could not justify throwing them away. When they reach the end of their useful life which will msot likely be next year, for a total of three years, I'd replace them with 4 Trojan T105 6V golf cart batteries. Four T105's weigh only about 204 pounds yet yield an amazing 450 amp hours. Compare that to an Exide Gold Marine Deep cycle 8D at 200 amp hours and 134 pounds a lot more punch for not a ton more weight. Plus a human being can actually handle a single 50 pound battery yet a single 134 pounder is nearly impossible to carry out of a boat each winter!Trust me those 4D's are a bear compared to four individual 6V's. and they are 35 pounds less than an 8D. You're getting more than double the out put for very little extra weight with 6V. Plus the 6V batteries will last a lot longer. Thicker plates mean longer life! My brother has a bank of Sam's Club 6V golf cart batteries in his boat going on 6 years now and he paid less than $200.00, at the time, for four of them!Keep the 4D's until they need to be replace then replace with either two 6V(225ah) or four 6V (450ah. More bang for the buck and a longer life!That picture by the way came from my web site and you're all more than welcome to view it here: http://www.pbase.com/mainecruising/acoustic

[Old Salt]

in Chris Conners post I am pretty sure they are a bank of 4D batteries.Also to Maine Sails points about weight. For deep cycle batteries Weight of the battery has a loose corallation to A/H's. Most 4D batteries I know are close to 110 lbs, although those are closer to 200 A/H's. I would think that if you are only getting 160 A/H's then under 100 lbs make sense.

[Jon W.]

It looks to me like there is a small battery to the left of the 4D's in that picture. I've been keeping my eyes open for a real small one, because I don't seem to have as much room in my battery compartment as some of the pictures seem to show. The batteries on my boat 2000' boat are turned 90 degrees from some of the later boats I've seen, and there isn't much room between the batteries and the point where the hull turns up. Zero room on the inside or the fore or aft side.

[Jon W.]

Interesting comparison photos. It looks like they cut out some of the fiberglass to put your batteries in 90 degrees from mine. I guess the compartment is the same size. Mine just looks fuller to me.If Maine Sail answers this thread, he might tell me what that small battery he used is.

[Jon W.]

Thanks. I didn't see your previous post.