Wiring In Series (pro vs con)

[john61ct]

Originally Posted by noelex 77

Sometimes the only modification is adding a sticker that says "deep cycle" .

Which is what I meant by getting ripped off.

I know of no 12V battery sold through mass retail that meet any definition of true deep cycle, all "dual purpose" really starters. Sam's GC2 are known good, maybe close to the minimum but great value for money. Costco's just a bit less so, being Johnson Controls.

[thomm225]

So, I had a new sailor ask me the other day about batteries in series.

He says "I'm hearing it's best to put batteries in series to get the most out of them!"

Since I have seen his boat and his one 12 volt battery, I let him know that IF he put his new 12 volt battery in series with the 12 volt battery he already has he'd then have a 24 volt source for his 12 volt systems

He mentioned something about hearing it was the right thing to do from what he (or a friend) had learned on a sailing forum.

You guys need to chill out on your detailed argument and get a life! Some folks are sort of reading your stuff

Btw, the Walmart Auto Battery I bought to start the diesel that was originally on the boat when I bought it in 2011 is now a house battery and is doing fine.

I paid $75.00 for it and charged it at 14.4 volts over the years with a $12.00 controller. Now I have an expensive $39.00 Windy Controller with float set at 13.6!

The Walmart 12 Volt Battery is in Parallel(not series!) with another 12 Volt Battery I bought at an automotive store for $88.00 and they are working well together

[mitiempo]

Originally Posted by thomm225

So, I had a new sailor ask me the other day about batteries in series.

He says "I'm hearing it's best to put batteries in series to get the most out of them!"

Since I have seen his boat and his one 12 volt battery, I let him know that IF he put his new 12 volt battery in series with the 12 volt battery he already has he'd then have a 24 volt source for his 12 volt systems

He mentioned something about hearing it was the right thing to do from what he (or a friend) had learned on a sailing forum.

You guys need to chill out on your detailed argument and get a life! Some folks are sort of reading your stuff

With that level of knowledge about his electrical system he should hire a professional.

[thomm225]

Originally Posted by mitiempo

With that level of knowledge about his electrical system he should hire a professional.

Yes, but after you have spent close to your budget on the boat and then the things you didn't think of ......well you then may try and cut corners.

It's like with another thread, Rod advised the guy with a "new" boat to have his wiring totally gone over because he couldn't get any power.

So the guy finally hires someone from the boat yard to do what any sailor that had left a boat on the hard for years would do which was to charge the batteries and clean the terminals.

Everything then worked so end of story....the guy forgets about the rest

Hopefully everything is fine and it's just an overzealous tech recommending things that may not need to be done

[TeddyDiver]

Originally Posted by ramblinrod

In contrast, when I have personally witnessed a cheap
12 Vdc bank, replaced with a cheap 6Vdc bank, and no other changes in systems or practices, there was no measurable difference in battery life span.
Sorry, Keyed

The only thing that proves is inadaquate battery management. Killing good and bad batteries is so easy...

[Pete7]

Originally Posted by noelex 77

A lot of cruisers are convinced that cheap 6v batteries last longer than cheap 12v batteries.

Agreed, but is this also down to the fact that those fitting 6v battery banks are probably more battery savy, than say those who are just replacing 12v batteries like for like? Therefore they have a greater understanding of the effects of deep discharges or consequences of not fully charging, so maintain their batteries to a higher standard.

Pete

[ramblinrod]

Originally Posted by Pete7

Agreed, but is this also down to the fact that those fitting 6v battery banks are probably more battery savy, than say those who are just replacing 12v batteries like for like? Therefore they have a greater understanding of the effects of deep discharges or consequences of not fully charging, so maintain their batteries to a higher standard.

Pete

Egg sacked lee. ;-)

[ramblinrod]

Originally Posted by john61ct

I know of no 12V battery sold through mass retail that meet any definition of true deep cycle, all "dual purpose" really starters.

There are "Deep Cycle" batteries of various quality and expected life span.

"True Deep Cycle" is just a term someone dreamed up, that has no definition, it's just BS.

If the manufacturer labels a battery "Deep Cycle", it is a "Deep Cycle" by their definition and declaration.

If you want to refer to them as low quality "Deep Cycle" batteries vs high quality "Deep Cycle" batteries, no prob.

Now, if you want to declare, "Big Box retailers tend to sell high volumes of low quality "Deep Cycle" batteries at discount prices", I would most certainly agree with that.

The only reason they can do that, is because that is what their target consumers prefer to purchase.

You can certainly continue to use the term "True Deep Cycle" when referring to batteries if you wish, just be aware, it may affect the credibility of your entire post. It proves you'll willingly use arbitrary, made up stuff in an attempt to support your argument. (In my experience, people tend to revert to this when they cannot find any verifiable facts to do so, because in most cases, their position cannot be substantiated.)

Which boils right down to the heart of the question, "Do cheap 6 Vdc batteries last any longer than cheap 12 Vdc batteries in a real life marine application, everything else being equal".

[ramblinrod]

Originally Posted by thomm225

So, I had a new sailor ask me the other day about batteries in series.

He says "I'm hearing it's best to put batteries in series to get the most out of them!"

Since I have seen his boat and his one 12 volt battery, I let him know that IF he put his new 12 volt battery in series with the 12 volt battery he already has he'd then have a 24 volt source for his 12 volt systems

He mentioned something about hearing it was the right thing to do from what he (or a friend) had learned on a sailing forum.

Thank you for your valuable contribution to this thread.

This is a perfect example why we cannot trust "Dock Speak".

We have no idea of the basis on which a person draws a conclusion.

Anyone considering DIY marine electrical modifications, needs to verify they are sufficiently knowledgeable and skilled to do so safely.

Doing something because, "I read on the internet it is better", like this poster connecting batteries in series vs parallel, is just foolish if one does not "know" if the posts (or their interpretation) have any truth behind them.

Ya pays your money and takes yer chances (and then spout on a cruising forum how great your decision was to help justify it in your own mind.)

[ramblinrod]

Originally Posted by TeddyDiver

The only thing that proves is inadaquate battery management. Killing good and bad batteries is so easy...

Please advise how you have drawn this conclusion?

On what basis have you determined that these batteries were not managed with the utmost care?

I consider my experience to be based on "average" battery management for the business geo territory I cover (North Shore of Lake Ontario).

Whether this "average" is "good" or "bad" battery management by anyone's arbitrary definition, or representative of "all cruisers" is moot.

It is what it is.

In my opinion, in general, those who have changed a house bank of 12 Vdc Marine Deep Cycle batteries to alternate voltage of comparable capacity, wasted their money on new battery boxes and wiring revisions, and possibly introduced faults that reduce reliability and safety.

If they increased the bank size, I believe that doing so with similar quality/cost 12 Vdc batteries in parallel, would have produced similar results for less effort and money, and improved the remaining capacity available on a battery failure.

[GrowleyMonster]

I decided my backup bilge pump should have a true backup power source, and by that I dont mean a second 48/12v dcdc converter. I took the ancient dusty old 12v group 31 batteries installed by the previous owner down to Sams for trade ins, and I intended to get two more Energizer GC2s. They don't carry Energizers any more. But they did have 215ah Duracell GC2's for $84.99 each. I will probably end up wiring these through a battery switch to the 12v distribution panel so I can take all the 12v loads off the 48v bank and relegate the dcdc converters to backup status. 215ah is enough juice to keep me going for some time, and I can still draw from my big bank if I need to.

I wonder what kind of 12v bank I can put together for $169.04?

[ramblinrod]

Originally Posted by thomm225

It's like with another thread, Rod advised the guy with a "new" boat to have his wiring totally gone over because he couldn't get any power.

This interpretation is false in so many ways.

I and other knowledgeable posters in that thread advised a person who seemed to have little marine electrical system knowledge, and purchased what sounded like a "derelict" boat, to inspect vessel wiring before connecting power sources, and if they didn't have adequate knowledge or skill (as it appeared they did not by their post) to have it inspected by a professional.

So the guy finally hires someone from the boat yard to do what any sailor that had left a boat on the hard for years would do which was to charge the batteries and clean the terminals.

If the hired person was a marine electrical professional, they inspected the wiring system, before connecting the power source, to assure it could be done so safely. (The uninformed, may not have realized it was done.)

For the simple reason, that not doing so, can be hazardous to ones health, and bad for business, if they start a fire, blow up a boat, or burn down a marina, due to gross wiring faults near improperly stored combustible materials.

A true marine electrical professional performs an assessment, every time they step aboard a vessel, and consider, "what are the chances..." before every action.

Whether a typical sailor would just connect terminals and see what happens, is why I go out of my way to warn those who are "ill-equipped" the possible outcome of their "un-informed" actions.

Everything then worked so end of story...

Exactly the outcome I was hoping for; nobody got hurt over a $1500 boat purchase, that was left on the hard, for an undefined period, other than "at least a year".

In my opinion, my advise was sound then, and still is.

What would you consider the validity of my advise, if he ignored it, connected the batteries to faulty wiring, causing sparks, an explosion, and was killed?

That people may put themselves in unknown danger is not justification for recommending others do so; it is merely ignorance and pure luck if they get away with it.

[ramblinrod]

Originally Posted by GrowleyMonster

I decided my backup bilge pump should have a true backup power source, and by that I dont mean a second 48/12v dcdc converter. I took the ancient dusty old 12v group 31 batteries installed by the previous owner down to Sams for trade ins, and I intended to get two more Energizer GC2s. They don't carry Energizers any more. But they did have 215ah Duracell GC2's for $84.99 each. I will probably end up wiring these through a battery switch to the 12v distribution panel so I can take all the 12v loads off the 48v bank and relegate the dcdc converters to backup status. 215ah is enough juice to keep me going for some time, and I can still draw from my big bank if I need to.

I wonder what kind of 12v bank I can put together for $169.04?

Prolly 2 x Grp 31's if you looked hard enough. I know a guy that declared he just bought 4 for C$85 each (~US$65).

[ramblinrod]

Originally Posted by GrowleyMonster

I decided my backup bilge pump should have a true backup power source, and by that I dont mean a second 48/12v dcdc converter. I took the ancient dusty old 12v group 31 batteries installed by the previous owner down to Sams for trade ins, and I intended to get two more Energizer GC2s. They don't carry Energizers any more. But they did have 215ah Duracell GC2's for $84.99 each. I will probably end up wiring these through a battery switch to the 12v distribution panel so I can take all the 12v loads off the 48v bank and relegate the dcdc converters to backup status. 215ah is enough juice to keep me going for some time, and I can still draw from my big bank if I need to.

I wonder what kind of 12v bank I can put together for $169.04?

Here's a link to the same vendor for group 31s that should provide similar performance.

https://www.samsclub.com/sams/durace...rchTerm=347589

They are $10 more each. Maybe they will last a little longer? Don't know. I do know that if one fails, you will still have 12 Vdc to operate your 12 Vdc devices.

Edit: Additional Info: If your budget is too sensitive to consider $10 more each, you may want to consider Grp 27 deep cycles from the same vendor for $80 ea. with slightly lower total A-hr rating.

https://www.samsclub.com/sams/durace...lp:product:1:3

[john61ct]

I have not seen any evidence the 12V "Duracells" are in fact East Penn Deka, nor true deep cycle. I'd suspect neither.

I stated long ago, my definition for that term is 800+ cycles at 50%. And that is scraping the bottom of the barrel.

A 12V Wally labeled deep cycle is deceptive, even fraudulent.

See the CCA rating. Cut it open and see the plate thickness. Actually try it for deep cycling see how long it lasts.

It is your refusal to acknowledge that reality that makes all your posts suspect in my view.