New Starting Bank 8V71Ti

[chuckbullett@gmail.com]

All; THank you for the comments about the racing battery idea.

In the end I went with the golf cart battery suggestion for the starboard bank beneath the galley sette.

At 67Lbs each, they were certainly easier to load in that the 4D's @ 105# ea which came out.

Same AH rating for 20 min as well. 165A @ 20 min.

The smaller flag terminals required a new battery cable set and distribution posts (Blue Sea Terminals) Everything except the batteries were sourced from McMaster-Carr. The Batts from a local commercial battery supplier.

Images below:


So four golf cart batteries in half of the space that the 4D's (x 4) occupied. We are generally warm in Northern California, between 50 and 70 degrees anyway, so do not anticipate any tremendous cold start issues.

Thanks again all.

 

[Boatsb]

That's a powernpost not a buss bar. You should not have more than 3 connections on it.

You need a blue seas 2104 buss bar.

 

[SEVEN]

Chuck when I’m ready to change mine out will you please help install and wire up all of the batteries. What a clean, professional job.

 

[MadHatter53]

Looks nice. any reason why you didn’t use the studs vs the flags?

 

[chuckbullett@gmail.com]

That's a powernpost not a buss bar. You should not have more than 3 connections on it.

You need a blue seas 2104 buss bar.

thanks Scott... you are correct... which is why there are only three connections on it.

good eye and product knowledge.

 

[chuckbullett@gmail.com]

Chuck when I’m ready to change mine out will you please help install and wire up all of the batteries. What a clean, professional job.

anytime Rusty.

 

[chuckbullett@gmail.com]

Looks nice. any reason why you didn’t use the studs vs the flags?

Thanks Mad. Mostly because of poor planning.

I wasn't sure of the post diameter when I ordered the batteries but was sure about the bolt size. The specifications list on the battery design was frankly lacking. I ordered all new jumpers and did my best with them. Now that they're here the middle jumper needs to get swapped out for a cable with "automotive" style stud clamps for the battery posts because as it stands right now the middle jumper is jacking up access to the fill caps.

The big dilemma or decision now: Do I remove the second battery box and reclaim the space for storage, or leave it for the eventual return back to large, 4D Batteries, if necessary.

I'd love to remove it because it gives me access to water the batteries and the generator exhaust stack components. Right now I lay a piece of scrap plywood over the unused battery box to position my chubby 60 year-old self into position to perform the required maintenance in there.

By the way, we keep a "Life Sling" on-board for MOB recovery. Here's another use for the life-sling... removing the 4D's from the Port side battery boxes:



We redid the galley about 6 years ago btw with new granite countertop and appliances... the floor is home depot engineered "teak" 4 foot strips. That is through the entire vessel with the exception of the flybride. That is getting new non skid this year.

 

[MadHatter53]

I would also support the wiring near the new stud posts. I wouldn’t trust two screws to hold up.

 

[SKYCHENEY]

What size are the jumper cables between the terminals? They need to be at least as large as the main cables which are probably 4/0

 

[davidwigler]

What size are the jumper cables between the terminals? They need to be at least as large as the main cables which are probably 4/0

I’ve heard that and I’ve heard one size smaller is ok. The minimum gauge for the main cables is determined by the starting amps and the length of the run from the battery bank to the appliance. If there is a long run, or if the main cables are oversized, why would the jumper cables need to be larger? I’m not arguing if it’s required by ABYC, just curious.

Now I’m curious. Suppose the starter pulls 100 amps at 32 volts. How many volts and amps are the jumper cables between each 8 volt battery carrying?

 

[Boatsb]

All the battery cables should be 4/0. Jumpers included.

 

[oscarvan]

All the battery cables should be 4/0. Jumpers included.

What he said. NOT the place to skimp. Giving the starters all they need avoids a world of potential hurt.

 

[SKYCHENEY]

Out-rush and in-rush of current to and from the terminals with a starting load is to ALL terminals so the cables all need to be of equal size including the jumpers.

 

[Photolomy]

Now I’m curious. Suppose the starter pulls 100 amps at 32 volts. How many volts and amps are the jumper cables between each 8 volt battery carrying?

The 8 volt batteries are in series, thus the current is going out the last battery, through the starter and back into the first, out the first into the second and so on, and thus it is 100 amps throughout. In a parallel situation, the current is divided (or added depending on how you look at it).

 

[Boatsb]

No reason to use less than 4/0 . With length and age of some of the components you want all the copper you can get in the battery cables.

 

[Captain Ralph]

When batteries are in serial, voltage goes up, current the same.
In parallel, voltage stays the same, current goes up.

Current and/or voltage loss is the worst event in any configuration. Cables and connects must be at the best to avoid any losses.

Nothing is for free.