New owner questions on starting and batteries

[spartonboat1]

For that size boat and $$ invested replacing ALL batteries since questionable is a cheap easy path to happiness. Any issues from there on are charger or load related. Both of those issues are impossible to pinpoint with weak old batteries. One bad cell will allow others to over charge and show proper voltage while the beginning of the end has come. Next dead cell means STUCK!

You definitely do not want a battery with a bad cell on one of the banks. That battery will "call" for the charger on a steady basis and "boil out" all the water. Next thing you know, you have a very, very hot battery, followed by a fire!!

Of all the products in the world, batteries are the cheapest, over their life. I am always amused when people "nurse" one or more batteries, when replacement is the answer. And yes, I have kept my 8D's past the usual 3 years, but the boat was getting very little use. I almost cut it too close one Spring and had enough juice to start the genny, followed by starting the mains. Those batteries came out in short order, after that!

P.s., this is on a 1972 43' DCFB, with 6-71N's; same as this thread references.

[spartonboat1]

The water filled weights about 100 lbs the gel weight about 160. Get some young backs with weight belts.

I believe the nominal weight of a lead-acid (water filled) battery is 140#'s. Young studs are the only people that should try to pull these. That's 70 #'s per man. I have changed them out with my brother-in-law's help, but that was 12-15 years ago, when I was much stronger.

Note that the most recent changeout was by the Admiral (wife) and me. I fabricated a "lift" on a roller assembly, with steel cable runout from a hand cranked winch. Each battery was winched out and then the new one lowered in by winch. The Admiral made "steering" movements pushing with her feet, to adjust each battery over its case. This worked well, but I also bought a large hand-cart to move each battery. Total changeout time was 5 hours or so.

Young studs is much faster. When I made my last battery purchase at NAPA, one of the employees moved each battery by himself!! No lifting, but picked them off a table and pushed them into my SUV. He was grunting...

[Reefgeorge]

A top shelf charging system has temp sensors on the batteries and derate the charging coltages with increased temperature. The best ones will shut down in temperature fault condition. This helps avoid a catastrophic failure and extends battery life.

George

[oscarvan]

I believe the nominal weight of a lead-acid (water filled) battery is 140#'s. Young studs are the only people that should try to pull these. That's 70 #'s per man. I have changed them out with my brother-in-law's help, but that was 12-15 years ago, when I was much stronger.

Note that the most recent changeout was by the Admiral (wife) and me. I fabricated a "lift" on a roller assembly, with steel cable runout from a hand cranked winch. Each battery was winched out and then the new one lowered in by winch. The Admiral made "steering" movements pushing with her feet, to adjust each battery over its case. This worked well, but I also bought a large hand-cart to move each battery. Total changeout time was 5 hours or so.

Young studs is much faster. When I made my last battery purchase at NAPA, one of the employees moved each battery by himself!! No lifting, but picked them off a table and pushed them into my SUV. He was grunting...

Quite a few years ago I put a battery bank under the floor of my 42 foot sailboat so we could run AC in our cabin overnight on the hook without running the genny. 4 8D's.....they were 150+ pounds and I hustled them from the dock into the cockpit up over the companion way, down the ladder and into the bilge. I did feel that.

Don't think I would try that today without rigging some sort of mechanical advantage.....

[Flymitch]

Thanks for all the opinions expressed here. As it has been years since I have owned a boat, they were all helpful. Today, my chosen marine electrician replaced all four batteries with -8's from West marine. These are 1780 cranking amps each. Was told, both house batteries were bad, and the engine bats at best provided 360 Cold Crank Amps on start up.Started the engines about 4 x at the dock today, all times without touching the parallel switch, both engines starting within 3-5 seconds each.There is no inverter, only the inverter panel, so guess I am going to rely on my two generators for 110 while at sea. Is it worth replacing the invertor for minimal 110 while under way?

[R D Young]

YES. Your engine is charging the batteries, so no need for the gennie to be running at the same time. Just be aware that depending on its capacity, the inverter may only be able to run a few convenience items.

[Boatsb]

West marine batteries?

Time to find a new mechanic.

[Flymitch]

West marine batteries?Time to find a new mechanic.

There are less expensive batteries, but these are the ones my electrical expert wanted to use. While they probably make a small percentage, besides the labor rate, I don't begrudge them this tiny profit. The less expensive batteries I had called on only had 1400 crank amps, so at least these have 1730 and easily exchangeable up and down the coast (Their selling point.) Besides cost, are there reasons why you suggest I need a new mechanic? Thanks.

[oscarvan]

Because he's taking advantage of your lack of knowledge. Costing you a lot more than you think.

[Boatsb]

There are less expensive batteries, but these are the ones my electrical expert wanted to use. While they probably make a small percentage, besides the labor rate, I don't begrudge them this tiny profit. The less expensive batteries I had called on only had 1400 crank amps, so at least these have 1730 and easily exchangeable up and down the coast (Their selling point.) Besides cost, are there reasons why you suggest I need a new mechanic? Thanks.

They are 1400 cca/ 1730 mca. I think west calls it marine cranking arms. I'll have to ask a marine what that means.

Theyre the same cca as most others in that line of heavy duty 8d batteries but sold with the usual west marine line of bs.

Interstate, royal, deka, west Penn and others sell as good as or better batteries for reasonable prices.