Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 24-09-2017, 00:37   #31
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 1,998
Re: Breaking in new batteries?

Your batteries are 225 AH at the 20 hour rate which is the standard method of rating batteries.

Why 2 banks? A single larger bank will be more efficient, will give you more AH than their rating for the same load, and will likely last longer as well.
__________________

mitiempo is offline   Reply With Quote
Old 24-09-2017, 04:24   #32
Registered User

Join Date: Jan 2017
Posts: 9,542
Re: Breaking in new batteries?

Yes, don't split the lead bank!

The larger total size bank gives you a higher percentage **usable** capacity, therefore your cycling will be shallower and you get longer lifetime.

Google Peukert's Law, same reason 20-hour capacity is higher than 5.
__________________

john61ct is offline   Reply With Quote
Old 24-09-2017, 05:28   #33
Moderator
 
Pete7's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 11,146
Images: 14
Re: Breaking in new batteries?

Quote:
Originally Posted by john61ct View Post
Another issue, perhaps the source of your misunderstanding.

A couple other relevant links: BU-701: How to Prime Batteries ‚€“ Battery University

Battery Break-in Recommendations
From your Battery University link:

Formatting a lead acid battery occurs by applying a charge, followed by a discharge and recharge. This is done at the factory and is completed in the field as part of regular use. Experts advise not to strain a new battery by giving it heavy duty discharges at first but gradually working it in with moderate discharges, like an athlete trains for weight lifting or long-distance running.

From your other link:

The following procedure will insure they reach their full potential. The 1st 10 to 20 complete charge/discharge cycles are critical to insure they reach 100%. New batteries should be charged before use and thereafter as follows:
Plug the charger in and leave it alone until the charger shuts off by itself. Then drive to discharge the batteries to 75% of battery pack capacity.

-------------------------------------------------------------------

Thanks for the advice but I for one won't be taking new batteries down to 10.5v or even 11.8v. I will fit new batteries and give them a good long charge, then maintain them with lots of solar. The current 12 deep cycle batteries are now 6 years old and doing fine. Why? because they don't go below 12.4v and are constantly fully charged with lots of solar.

Pete
Pete7 is offline   Reply With Quote
Old 24-09-2017, 06:40   #34
Registered User

Join Date: Jan 2017
Posts: 9,542
Re: Breaking in new batteries?

Quote:
Originally Posted by Pete7 View Post
not to strain a new battery by giving it heavy duty discharges
Yes, that is referring to current Amps.

That is why the draw-down load rate is carefully controlled, limited to the very gentle 20-hour rate.

Just like a standard capacity test, the only accurate measure of bank state of health. It really is a good idea to get an initial benchmark load test at the same time as the commissioning cycles, since they are nearly the same process.


Quote:
Originally Posted by Pete7 View Post
The current are now 6 years old and doing fine.
You think 6 years is long? Not. A better quality bank well maintained often goes 10-12, no problem.

Of course many people keep using their bank long after they're past the point where they should be scrapped, that's not what I'm talking about.

Industry standard is when AH capacity has walked down to 80%.

Going to 75 or even 70% is usually fine, but after that they deteriorate, and the chances of catastrophic failure increases much faster.

For those regularly connecting to shore power unexpected failures may usually just be an inconvenience.

For cruising liveaboards and long passages, periodic load testing after the bank's first year or two becomes more important, especially if you don't want to replace the bank unnecessarily early.

That is the same level of "stress" as the commissioning protocol being discussed.

As Maine Sail makes clear, that stress is minimal as long as the draw down is closely controlled and as soon as the bottom reached a gentle restore charge begins immediately.

The completely normal level of abuse batteries usually get by 95% of boat owners over their life is what hurts bank lifetimes, not a half dozen load tests as part of overall careful bank management.

Quote:
Originally Posted by Pete7 View Post
Thanks for the advice but I for one won't be taking new batteries down to 10.5v or even 11.8v.
Your bank, your call of course. At least you are making your decisions based on solid information, this particular topic is one most owners never even heard of.
john61ct is offline   Reply With Quote
Old 24-09-2017, 22:52   #35
Registered User

Join Date: Nov 2012
Posts: 233
Images: 1
Re: Breaking in new batteries?

Quote:
Originally Posted by mitiempo View Post
Your batteries are 225 AH at the 20 hour rate which is the standard method of rating batteries.

Why 2 banks? A single larger bank will be more efficient, will give you more AH than their rating for the same load, and will likely last longer as well.
Thanks for confirming the capacity. Trojan gives ratings at 5, 10, 20 and 100 hours, but I kinda "knew" in the back of my mind that 20 was what I wanted to focus on. As you say: 225 AH

Regarding two banks, that's the way the boat came. The bank of two is, in principle, the start bank, while the bank of four is the house bank. I am inclined to keep it that way so that I am less likely to be without power for starting. I can imagine myself running down the house bank while sailing with the engine off. I am considering adding two batteries. I guess I could increase my house bank to six in total (thus about 600 AH nominal capacity for the house bank). It partly depends on how costly and complicated it'll be to set up -- it's a boat, so I know for certain that doing what appears to be a simple while sitting here at my computer will be much more complicated and costly in reality!
Lantau is offline   Reply With Quote
Old 24-09-2017, 23:01   #36
Marine Service Provider

Join Date: Sep 2008
Location: Victoria B.C.
Boat: CS27
Posts: 1,998
Re: Breaking in new batteries?

Quote:
Originally Posted by Lantau View Post
Thanks for confirming the capacity. Trojan gives ratings at 5, 10, 20 and 100 hours, but I kinda "knew" in the back of my mind that 20 was what I wanted to focus on. As you say: 225 AH

Regarding two banks, that's the way the boat came. The bank of two is, in principle, the start bank, while the bank of four is the house bank. I am inclined to keep it that way so that I am less likely to be without power for starting. I can imagine myself running down the house bank while sailing with the engine off. I am considering adding two batteries. I guess I could increase my house bank to six in total (thus about 600 AH nominal capacity for the house bank). It partly depends on how costly and complicated it'll be to set up -- it's a boat, so I know for certain that doing what appears to be a simple while sitting here at my computer will be much more complicated and costly in reality!
Batteries in a bank should all be the same age and type. Best solution is to combine all your batteries in one bank and buy a group 24 start battery.
mitiempo is offline   Reply With Quote
Old 25-09-2017, 06:01   #37
Registered User

Join Date: Dec 2009
Location: Cruising, now in USVIs
Boat: Taswell 43
Posts: 427
Re: Breaking in new batteries?

Based on both advice we received from experts as well as blog and manufacture's advice,when we redesigned our 12v system, we built the house bank with 6 T-105s and an isolated group 24 start battery. Their logic was...use batteries for what they were designed for, ie, the house is multiple deep cycles but generally not a big single draw, and the starter draw(big draw but not frequent small loads). The plates and battery designs are different, and the logic made sense. We connected the start battery to the house bank with a Balmar duo-charge and a parallel switch(that we've never had to use...yet), and start both the engine and the genset from that starter battery, while all the charging(solar, wind, and batt chrgr) go to the house bank. So far-now some 13 years-the scheme has worked perfectly. Mitiempo's suggestion above is a good one.
sailcrazy is offline   Reply With Quote
Old 25-09-2017, 15:40   #38
Registered User

Join Date: Nov 2012
Posts: 233
Images: 1
Re: Breaking in new batteries?

Quote:
Originally Posted by sailcrazy View Post
Based on both advice we received from experts as well as blog and manufacture's advice,when we redesigned our 12v system, we built the house bank with 6 T-105s and an isolated group 24 start battery. Their logic was...use batteries for what they were designed for, ie, the house is multiple deep cycles but generally not a big single draw, and the starter draw(big draw but not frequent small loads). The plates and battery designs are different, and the logic made sense. We connected the start battery to the house bank with a Balmar duo-charge and a parallel switch(that we've never had to use...yet), and start both the engine and the genset from that starter battery, while all the charging(solar, wind, and batt chrgr) go to the house bank. So far-now some 13 years-the scheme has worked perfectly. Mitiempo's suggestion above is a good one.
Thanks Mitiempo and Sailcrazy. I hadn't thought of that, even though it's the setup I had in my previous boat! (And it had a nice switch system with separate switches for house and start, and a bypass built in just in case I needed the house bank to start the engine. Very well thought out and simple -- no crazy 1-2-both switch.) I'm sure I can find room for a Group 24-sized start battery. The complexity and time may be in how to rewire the whole system. That could be a show stopper. My circumstances mean that I will have only a short time to complete a long list of projects on the boat.
Lantau is offline   Reply With Quote
Old 25-09-2017, 18:10   #39
Registered User

Join Date: Jan 2017
Posts: 9,542
Re: Breaking in new batteries?

Quote:
Originally Posted by sailcrazy View Post
We connected the start battery to the house bank with a Balmar duo-charge and a parallel switch(that we've never had to use...yet), and start both the engine and the genset from that starter battery, while all the charging(solar, wind, and batt chrgr) go to the house bank. So far-now some 13 years-the scheme has worked perfectly. Mitiempo's suggestion above is a good one.
Yes tried and true standard best practice.

I'm looking at a variant, feedback welcome, didn't want (for once! 8-) to hijack the thread, so please discuss there, not back here http://www.sailnet.com/forums/showthread.php?t=298497
john61ct is offline   Reply With Quote
Old 25-09-2017, 19:45   #40
Registered User

Join Date: Nov 2012
Posts: 233
Images: 1
Re: Breaking in new batteries?

Quote:
Originally Posted by sailcrazy View Post
Based on both advice we received from experts as well as blog and manufacture's advice,when we redesigned our 12v system, we built the house bank with 6 T-105s and an isolated group 24 start battery. Their logic was...use batteries for what they were designed for, ie, the house is multiple deep cycles but generally not a big single draw, and the starter draw(big draw but not frequent small loads). The plates and battery designs are different, and the logic made sense. We connected the start battery to the house bank with a Balmar duo-charge and a parallel switch(that we've never had to use...yet), and start both the engine and the genset from that starter battery, while all the charging(solar, wind, and batt chrgr) go to the house bank. So far-now some 13 years-the scheme has worked perfectly. Mitiempo's suggestion above is a good one.
What are you using for a start battery? Is it the Trojan Group 24 flooded marine/RV battery? How big is your engine?

I'm asking because, on studying this issue a bit more, I realized that my boat's 100 HP engine supposedly requires two 12v start batteries (about 600 cca each). However, it's actually got two 6v batteries (Trojan T-105). Together they of course make a 12v battery, and experience proves that they are happy to start the engine, showing that the CCA is adequate. That said, it's an easy-starting engine, so I have never had to really put the start batteries to the test of cranking more than once.
Lantau is offline   Reply With Quote
Old 25-09-2017, 21:08   #41
Registered User

Join Date: Dec 2009
Location: Cruising, now in USVIs
Boat: Taswell 43
Posts: 427
Re: Breaking in new batteries?

Lantau...my bad! I miss-read my own equipment list. We have an Atlas Gp 31 Mx-Free start battery. It's conventional car battery, rated at 800CCA, and 1000CA. It starts our Yanmar 4JH-TE 4-cyl diesel eng, rated at 55hp, or our 6.5kva genset with a 3-cyl Kubota 24hp diesel. Sorry for the miss-quote.
sailcrazy is offline   Reply With Quote
Old 25-09-2017, 22:51   #42
Registered User

Join Date: Nov 2012
Posts: 233
Images: 1
Re: Breaking in new batteries?

Quote:
Originally Posted by sailcrazy View Post
Lantau...my bad! I miss-read my own equipment list. We have an Atlas Gp 31 Mx-Free start battery. It's conventional car battery, rated at 800CCA, and 1000CA. It starts our Yanmar 4JH-TE 4-cyl diesel eng, rated at 55hp, or our 6.5kva genset with a 3-cyl Kubota 24hp diesel. Sorry for the miss-quote.
Thanks. I'm shocked that you have not memorized every last piece of gear on your boat. Shame!

I'm a bit embarrassed because I'm not sure if my engine starts on 12v or 24v. It must be 12v because I've got two Trojan 6v in the "start" bank, but the book says 24v. I'm guessing wildly, and no doubt showing the limits of my intellect, but maybe the marinization process included fitting a 12v starter. Regardless, unless I'm mistaken, the two Trojan 6v batteries in my start bank have substantially more cranking power than a single Trojan 12v of the same external dimensions of each 6v (but I realize that capacity is not strictly a function of the box size -- although you can fit only so many plates in there). Then again, I think my Trojans aren't strictly intended for starting. I'm thinking (weakly) out loud...

Clearly I need an electrician! I was going to get one anyway, but I learn a lot trying to figure stuff out for myself, with the help from other cruisers, of course.

P.S. (and wildly off topic): I had a Yanmar 4JH on my last boat. Excellent engine. Is the "TE" for turbo? If so, surely it has more than 55hp because mine wasn't a turbo and it was also 55hp at max (not continuous) power. Might yours be more like 75hp (on paper).
Lantau is offline   Reply With Quote
Old 26-09-2017, 16:08   #43
Registered User

Join Date: Jan 2017
Posts: 9,542
Re: Breaking in new batteries?

Returning to the "controversy" of my reply to the OP, a great report from an authoritative source:
http://www.cruisersforum.com/forums/....php?p=2486882
john61ct is offline   Reply With Quote
Old 26-09-2017, 16:16   #44
Registered User

Join Date: Jan 2017
Posts: 9,542
Re: Breaking in new batteries?

Quote:
Originally Posted by Lantau View Post
I think my Trojans aren't strictly intended for starting
Cranking is a trivial load for a quality true deep-cycling batt of any size.

Really **large** high-current and longer-lasting loads e.g. a huge windlass may benefit from a big Starter's thinner plate design, but for batt longevity I would use thick-plate deep-cycling and just go for more AHs.

Quote:
Originally Posted by Lantau View Post
the two Trojan 6v batteries in my start bank have substantially more cranking power than a single Trojan 12v
Yes, Trojan's own docs show that, in general multiple smaller-voltage cells in series deliver more power, are more robust and longer-lived than 12V, especially in automotive sizes.

Of course the top-notch mfg do produce exceptions which prove the rule
__________________

john61ct is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Breaking-In a New Generator lorenzo b Electrical: Batteries, Generators & Solar 12 26-08-2009 12:31
Breaking Waves AND Capsize Pics ssullivan Off Topic Forum 32 07-04-2008 17:18
Major important Breaking news. Alan Wheeler Off Topic Forum 6 12-10-2006 11:59
breaking news! little boat General Sailing Forum 0 28-04-2006 07:52



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 02:20.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.