Wiring In Series (pro vs con)

[rwidman]

Originally Posted by Zil

......... Using proper sized cables and lugs will be as good or better than internal connections.

Again, that's not correct. Cables and lugs, no matter how well they are done, will have more resistance than internal cell connections. Internal connections are much shorter and have fewer connection points. This translates to less resistance and less voltage drop at high loads.

Think about it.

[rwidman]

Originally Posted by TeddyDiver

Real battery banks are 2v batteries in series.. Just saying

There are no 2v batteries. The section that makes two volts is called a "cell". A "battery" is made up of two or more cells.

[TeddyDiver]

Originally Posted by rwidman

There are no 2v batteries. The section that makes two volts is called a "cell". A "battery" is made up of two or more cells.

Nope, a cell in this regard consists of the vessel the plates and the electrolyte. A battery has also positive and negative external contacts..

BR Teddy

[Bleemus]

Originally Posted by rwidman

There are no 2v batteries. The section that makes two volts is called a "cell". A "battery" is made up of two or more cells.

Really? Dont tell Trojan.

[ramblinrod]

Originally Posted by TeddyDiver

I didn't say 6 x 2Vdc.

Well, if you don't post what you mean, all we can do is guess.

A previous poster indicated a bank consisting of 2Vdc cells in series is the ultimate. Based on the content of your post, I thought you were agreeing with that statement.

If this is not the case, why don't share with us what you do mean?

The principle of using 12vdc batteries has limited your options.

How so? If one is designing a 12 Vdc system, how does using 12 Vdc batteries limit options, other than not using batteries of different voltage. There are certainly sufficient options of 12 Vdc batteries available to meet any reasonable cruisers budget and life expectancy needs.

Using 2v batteries, programmable loading devices and voltage regulators having 7 or 8 (or anything.. ) 2v batteries in series has redundancy enough.

I disagree. A programmable loading device can help to monitor battery capacity. (An analog 12 Vdc load tester will do pretty much the same thing for 12 Vdc FLA batteries, albeit with a 100 A fixed load, for way, way, way less money.) Neither of these devices will do anything to address the lack of redundancy in a 12 Vdc house bank consisting of a 2 Vdc series string.

Any parallel connected battery bank is far more vulnerable compared to pure series bank (even 6x2vdc) and includes the risk of destroying the whole bank in case of one shorted cell.

How so?

a) If a 2 Vdc cell fails, in a 6 x 2 Vdc bank, it will reduce the voltage available by 2.15 Vdc (at full charge). For all intents and purposes, the bank is dead,
until that cell is replaced.

b) If a cell in a 12 Vdc house bank battery fails, it will reduce the voltage available by 2.15 Vdc, until the defective battery is disconnected (by simply flipping the isolation switch or disconnecting the terminal).

After which, all other batteries in the bank should now function properly. The shore power charger will still work, the alternator will still work, the solar charge controller will still work, and the wind or water powered generator will still work. Nothing else to do, but charge up the depleted bank by normal means. At one's leisure, they can replace the defective battery, to restore full capacity.

So please, enlighten me with how a series string of 2 Vdc cells, has adequate redundancy in a 12 Vdc nominal system to compensate for a shorted cell?

The risk of reduced battery bank life is also present if some of the batteries has any problems (poor connection, internal resistance differs, waterlevel...) you name it, anything that can be wrong with a battery affects to all other parallelly connected batteries..

Poor (open) Connection:

Series String: All current stops. Dead. Nothing works until repair made, despite how many good connections there are in the string. Fix now to get anything to work.

Parallel Bank: 12 Vdc still available. Everything still works (except the battery(s) disconnected by the open circuit). Fix at your leisure to restore full capacity.

Internal Resistance Differs:

Series String: Charge current and capacity through all cells is reduced until defective cell replaced.

Parallel Bank: Lower impedance batteries accept greater charge current, (as ususal).

Water Level:

If someone neglects to add water to a vented battery, catastrophic battery failure will eventually occur.

Series String: The entire string is disabled, and everything is dead, until the defective cell is replaced.

Parallel Bank: Disconnect the defective battery, the rest of the bank works fine, operating all 12 Vdc devices until the battery is replaced to restore full capacity.

[Bleemus]

Gee, I wonder what happens if a single cell shorts. :facepalm

[john61ct]

Originally Posted by ramblinrod

There are certainly sufficient options of 12 Vdc batteries available to meet any reasonable cruisers budget and life expectancy needs.

If you mean true deep-cycle batteries, only a tiny fraction of available models are sold in 12V form factors.

99.99% of people buying batteries **labeled as** "marine" or deep cycled are being deceived, not getting their money's worth, and their banks won't last near half as long as they would if they were better informed.

Is the above also something with which you would "disagree"?

Of course the weasel words "reasonable" and "budget" gives an out, but IMO reasonable cruisers would be ones willing to spend a bit more up front in order to save money long term.

[john61ct]

I don't **think** anyone is arguing against paralleled banks offering some greater level of redundancy.

I just don't see what that fact has to do with using 12V batteries as opposed to lower voltage in series, which can of course then be paralleled.

[leftbrainstuff]

Wow. Some serious ocean boiling about batteries going on here.

Our trusty old flooded lead acid friends are little changed in a 100 years.

Keep em wet, keep em charged, only plan to consume about a third of their capacity and they'll last for years.

Our 6 x Trojan T105s are 10 years old this year. They're still going well but are quite thirsty these days.

I plan to work them hard in the next year. If I don't replace them with like for like I might even replace them with carbon foam batteries.

[john61ct]

Just say Firefly Oasis, category of one.

And currently only available in 12V. Hopefully 6V coming soon.

[rwells36]

Originally Posted by john61ct

Just say Firefly Oasis, category of one.

And currently only available in 12V. Hopefully 6V coming soon.

An Asian company has purchased Fire Fly Oasis and I have exchanged emails with the new owner. I learned you can order 2v or 4v from their plant over seas. PM me if you'd like that contact information. Rick

[john61ct]

Indian or Chinese?

So why not just publish it?

If not then yes PM please.

[rwells36]

Originally Posted by john61ct

Indian or Chinese?

So why not just publish it?

If not then yes PM please.

Dear Mr. Richard

Thanks for your mail to us.

Yes the batteries are in stock and could be export to your place direct from Ahmadabad, India. which may takes a time around 6-8 weeks or you can buy it from our US Office in Washington if you are in USA.

The address of our USA office is -

Firefly International Energy Co
6533 N. Galena Rd.
Peoria, Illinois USA 61614
Ph. No. +1.309.402.0701 EXT. 309
Contact Person Name – Chen Jun

Contact Person mail id– cjun@fireflyenergy.com



You may contact Mr. Chen Jun for purchase of Firefly Battery in USA.


Please let me know if you have any further question.

Warm Regards,
Firefly Battery

[OceanPlanet]

Originally Posted by rwells36

Dear Mr. Richard

Thanks for your mail to us.

Yes the batteries are in stock and could be export to your place direct from Ahmadabad, India. which may takes a time around 6-8 weeks or you can buy it from our US Office in Washington if you are in USA.

The address of our USA office is -

Firefly International Energy Co
6533 N. Galena Rd.
Peoria, Illinois USA 61614
Ph. No. +1.309.402.0701 EXT. 309
Contact Person Name – Chen Jun

Contact Person mail id– cjun@fireflyenergy.com



You may contact Mr. Chen Jun for purchase of Firefly Battery in USA.


Please let me know if you have any further question.

Warm Regards,
Firefly Battery

We (OceanPlanet Energy) manage the distribution of Firefly for the marine market in North America. We communicate with Jun almost every day.

We have over 500 of the group 31 size batteries on backorder with Peoria, which is the only size in production there.

The Firefly facility in India is working on making group 31's, and also the larger 2v & 4v. However as of now none of those have tested out to nearly the full specifications, so we are not offering them yet. When and if they become available with consistent test results (we will test them ourselves and also have done by 3rd parties), we'll gladly offer them for sale.

Until then, only the group 31 batteries, made in Peoria, are available in the US.

Bruce

[Pete7]

Originally Posted by leftbrainstuff

Wow. Some serious ocean boiling about batteries going on here.

Our trusty old flooded lead acid friends are little changed in a 100 years.

Keep em wet, keep em charged, only plan to consume about a third of their capacity and they'll last for years.

Almost as good as an anchor thread

As to those 2v batteries, very nice but how many production yachts could take them without serious modifications?

i actually agree with you and Ramblinrod, we have a pair of high quality type 31s that are now 6 years old and doing well because they live constantly hooked up to solar. The other point is that T105s are £140 ($180) incl delivery in the UK so not the cheap option.

https://www.tayna.co.uk/T-105-Trojan...105-P7253.html