New Starting Bank 8V71Ti

[chuckbullett@gmail.com]

All;

While there's a thread about re-inventing the house bank here, what about new battery technology for starting banks?

I'm trolling for comments on using 16V racing batteries for the starboard starting bank.
A few battery sales folk who love selling me 4D 8V batts are suggesting I try them out... They're a ton easier to manage than the 100 lb. 4d's. and I'll save space in the battery boxes.

If anything I'll have to build up some blocking to keep them where I put them if we go this way.

He also suggests going with four them them... two in series, paralleled with another series set.

Comments please? Has anyone done this? Important fact: 32V starting and house banks on Chartmaker.

This is the starboard bank which is starting only. Dave Wigler on here speaks favorably about using the golf cart batts too... but when i discovered the 16V racing batteries as an option, it sort of turned me around on new possibilities.

Thanks.

 

[SKYCHENEY]

How do the specs compare to the current bank? Do you have a link to the specs?

 

[Photolomy]

What CCA is required for an 8V71TI?

 

[oscarvan]

What CCA is required for an 8V71TI?

Some in the archives stated recommended was 1900.

 

[Avenger]

It is.

https://www.samsmarine.com/forums/s...2vdc-CCA-requirement-for-DD8v71-engines/page2

 

[davidwigler]

Some in the archives stated recommended was 1900.

That’s at 12 volts. He’s got 32 volts.

 

[Photolomy]

That’s at 12 volts. He’s got 32 volts.

Yeah, I was about to say. 8v195's are only rated at 980 CCA. And they are hooked up in series, so the amps are still 980. But that makes sense now, 1900 at 12v.

The 16v racing batteries should actually work, 4 of them at least, in series and in parallel. And they only weigh ~40 lbs each. And have a 12v tap. Longevity though?

 

[SKYCHENEY]

Yeah, I was about to say. 8v195's are only rated at 980 CCA. And they are hooked up in series, so the amps are still 980. But that makes sense now, 1900 at 12v.

The 16v racing batteries should actually work, 4 of them at least, in series and in parallel. And they only weigh ~40 lbs each. And have a 12v tap. Longevity though?

Flag terminals? Because automotive terminals are worthless.

 

[SKYCHENEY]

And if they're AGM, good luck finding a 32v charger to charge AGM. They won't last long if you use the lead/acid charge profile.

 

[SKYCHENEY]

Just buy the OEM Rolls 8v batts and be done with it for the next 10-13years. You'll save money in the long run. But what do I know?

I know nothing. I'm not an electrical engineer. So, I just go with what the original engineers did. And that seems to work great.

 

[Jammin']

Flag terminals? Because automotive terminals are worthless.

Why do you say automotive terminals are worthless? Apart from having an extra connection to keep clean and tight, it would seem to me that the contact area around a battery post would actually be greater than a flag terminal. I'm not arguing. I'm genuinely curious. I just bought a Lifeline AGM 8D last week with an L-blade flag terminal because I like the simplicity, but from a current flow perspective, I don't understand the down side.

 

[SKYCHENEY]

Why do you say automotive terminals are worthless? Apart from having an extra connection to keep clean and tight, it would seem to me that the contact area around a battery post would actually be greater than a flag terminal. I'm not arguing. I'm genuinely curious. I just bought a Lifeline AGM 8D last week with an L-blade flag terminal because I like the simplicity, but from a current flow perspective, I don't understand the down side.

I've seen more melted automotive terminals than flag over the years. OEM terminals were heavy flag terminals.

 

[davidwigler]

Yeah, I was about to say. 8v195's are only rated at 980 CCA. And they are hooked up in series, so the amps are still 980. But that makes sense now, 1900 at 12v.

The 16v racing batteries should actually work, 4 of them at least, in series and in parallel. And they only weigh ~40 lbs each. And have a 12v tap. Longevity though?

1900 amps at 12 volts is the same watts as 712.5 amps at 32 volts.

 

[Avenger]

That’s at 12 volts. He’s got 32 volts.

Guess I should read more carefully.

Anyway, I cracked open the Detroit service data book again, and interestingly it calls for 950 CCA above 32F° for both 24V and 32V systems.

1250 CCA below 32°F in case you're planning on ice boating.

 

[chuckbullett@gmail.com]

Hi All;

Continuing the discussion about cranking amp requirements. The 11-4-1 8-Volt 4d's I just put in are rated at 145A for 20 Hours. Four of them in series are still only 145AH... for 20 hours!

The 16V Batts are a different breed, rated for 950A for 15 seconds. http://www.atiracing.com/products/batteries/index.html. More study is needed, and maybe a call to the manufacturer's support team to ask about alternator charging.

As someone pointed out here the 12V tap make for possibilities. Again- we have more options now in battery strategy. The 12 Volt taps? Very cool. I have 12V and 24V banks on board for various appliances and for a huge Lofren windlass. Those all have their own chargers. Using the 12V tap for instrumentation instead of relying on the newmar DC-DC converters is an interesting notion... a lot of rewiring (and documentation).

There are perhaps as many as 8 Newmar DC-to-DC Converters on board too... I see lots of retirement projects ahead.

So many options...

So yes, in the end, we'll probably try to buy some more 4d's and call it good (and shutup).

The 16V batteries are rated as a starting battery only, the rated ampacity draw "metric" is entirely different. But can they turn over a 9-Liter V8? Absolutely.

 

[davidwigler]

The 20 hour rating is for deep cycle comparisons and has nothing to do with CCA. CCA is how much current the battery can supply in a short amount of time (usually 30 seconds), Amp-hours is how long the battery can output a certain current.

 

[Photolomy]

Hi All;

Continuing the discussion about cranking amp requirements. The 11-4-1 8-Volt 4d's I just put in are rated at 145A for 20 Hours. Four of them in series are still only 145AH... for 20 hours!

The 16V Batts are a different breed, rated for 950A for 15 seconds. http://www.atiracing.com/products/batteries/index.html. More study is needed, and maybe a call to the manufacturer's support team to ask about alternator charging.

As someone pointed out here the 12V tap make for possibilities. Again- we have more options now in battery strategy. The 12 Volt taps? Very cool. I have 12V and 24V banks on board for various appliances and for a huge Lofren windlass. Those all have their own chargers. Using the 12V tap for instrumentation instead of relying on the newmar DC-DC converters is an interesting notion... a lot of rewiring (and documentation).

There are perhaps as many as 8 Newmar DC-to-DC Converters on board too... I see lots of retirement projects ahead.

So many options...

So yes, in the end, we'll probably try to buy some more 4d's and call it good (and shutup).

The 16V batteries are rated as a starting battery only, the rated ampacity draw "metric" is entirely different. But can they turn over a 9-Liter V8? Absolutely.

The 145Ah rating in't really applicable. The 16v could certainly start the engines. I was thinking 4 of them for each engine, in parallel and in series. You would get 32v and double the amps. However, even in that setup (4 batteries), you still wouldn't have the capacity of the larger batteries in terms of how many times or for how long you could try to start the engines. Mine start very quick. Even a pair of 16v batteries would do it, but I would rather have at least 4.

 

[oscarvan]

I know nothing. I'm not an electrical engineer. So, I just go with what the original engineers did. And that seems to work great.

I appreciate your thinking, but I have to ask: What would the engineers have done 40-50 years ago if they had todays technology available?"

 

[SKYCHENEY]

I appreciate your thinking, but I have to ask: What would the engineers have done 40-50 years ago if they had todays technology available?"

Used 12 or 24v

 

[SKYCHENEY]

12v taps on a 16v battery are for only very minimal draw. If you use it for more than that, it will put an imbalance in the cells and it will not charge properly. One cell will continually be overcharged.

Go ahead and try it then let us know when they fail in 3-4 years. My 10 year old start bank may still be going by then.