Wiring In Series (pro vs con)

[john61ct]

Originally Posted by ramblinrod

Here are some links for you.

Can a Lithium-Ion Battery Fire Be Put Out with a Conventional Fire Extinguisher? - boats.com

http://www.economist.com/blogs/econo...st-explains-19

Managing the lithium (ion) battery fire risk - Industrial Fire Journal - Fire & Rescue - Hemming Group Ltd

Did you read them yourself?

Only the first is about LFP, and confirms what I said.

The rest have nothing to do with LFP.

Note I'm not saying you can't find something if you look hard enough, wood isn't a perfectly safe material either.

[ramblinrod]

Originally Posted by john61ct

Did you read them yourself?

Only the first is about LFP, and confirms what I said.

The rest have nothing to do with LFP.

Note I'm not saying you can't find something if you look hard enough, wood isn't a perfectly safe material either.

In general, wood aboard a boat does not burst into flames, when used in accordance with sound practice.

There have been incidences of LiFeP04 Battery Management Systems failing in a most catastrophic way.

Anytime one attempts to store higher density energy, safety risks increase.

Is a LiFeP04 battery safe?

Not enough data available. Not as safe as 12 Vdc FLA in my opinion.

It is dependant on an electronic BMS to prevent it from running amuck, and as we all know, battery management systems can fail. It can accept and discharge electrical current at a much higher rate.

Again, there are pros and cons to all design compromises. LiFeP04 is certainly no exception.

Notwithstanding, I concur that the technology looks promising. I would consider it for a vessel that was extremely weight or space consumption sensitive. e.g. highly competitive racing vessel.

For cruising vessels, I consider it prohibitively expensive, less accessible, and less safe.

I suspect vastly superior technology will be available during the initial installation expected life-span.

Therefore, my general recommendation to cruising customers is to stay with what you have if possible for a couple years, and if not, replace with lowest cost solution, (often replace with same) until we see what unfolds in the near future, that is both safe and economically justifiable.

Converting a from 12 Vdc house bank to any other voltage, is not a wise move IMHO. I don't think the user will typically see increased value for money, and will wish they had waited for the new breed of battery when it comes out.

But for those who wish to accept the risks today, all the power (har) to them, hopefully it doesn't end up burning the boat. ;-)

[ramblinrod]

Had an interesting conversation with my battery supplier yesterday, to whom I mentioned this thread.

He shook his head and laughed.

"With the current plate envelope technology, I haven't seen a Deka 12 Vdc Deep Cycle marine battery with a cell short in over 20 years."

Really?

"The plates are enclosed in an envelope, so that plate material shed, cannot fall to the bottom of the battery and cause a short."

He added, "Any risk of a low impedance short due to a manufacturing defect or total plate failure in operation, is pretty much eliminated."

So what would additional reservoir in the bottom of the battery do?

Zero, nuthin', nada. The shed plate material can't even get to the bottom of the battery.

What does the additional reservoir above the plates do? Keeps the plates in electrolyte, if levels are allowed to go down a bit between servicing, and when the boat is heeled.

I can't speak to all other manufacturers designs, but in my experience East Penn 12 Vdc Marine Deep Cycle batteries are pretty good. What they may not have in specified "lab cycles", they make in economy. In practice, one gets about the best deep cycle / dollar obtainable, in my experience.

But if one wishes to install a series string of expensive 2 Vdc cells, and then carry around an expensive spare (or 2 because they are hard to find in remote locations), sitting idle, not contributing to anything under normal operation, secured somewhere so it doesn't fly around like a cannon ball, and somehow keep it charged up, they most certainly can.

Here's a link to a 2Vdc Gel 1000 A-hr battery distributed by Mastervolt one of the leading marine power management manufacturers.

https://www.invertersupply.com/index...oducts_id=3184

That's right, over $1000 each. So for a single series string of 6 batteries to produce 12 Vdc, we're talking about $6000. Throw in a couple spares, and we're talking $8000, plus shipping, plus taxes.

Or if one wishes to purchase and install an expensive DC-DC converter, so if a 2 Vdc battery in a series string goes down they can still produce 12 Vdc, they most certainly can. Here's a link to the highest output model produced by Mastervolt...

https://www.invertersupply.com/index...oducts_id=3210

That's right, if relying on this to run house loads from a 12 Vdc, 1000 A-hr bank of 2 Vdc batteries in series, for their $580 (plus shipping, plus installation wiring, and labour if hired, plus taxes) they get a whopping 20A output. About enough to run a fridge, autohelm, and VHF on a typical cruising boat. Anything more, and it just doesn't have the guts.

Now remember, this 20A output is on a vessel that "needs" a 1000 A-hr bank, a pretty energy hungry beast.

Nothwistanding that the 1000 A-hr bank is now reduced to 800 A-hrs, and all the charging system voltages have to be modified (which may include shore power, alternator, wind, solar, and water generator) if they are so capable, else disabled so they don't cook the rest of the 2 Vdc batteries. (You've already got a single $1000 battery to replace, so it would be wise not to have replace 5 more.)

In comparison, 9 x Deka Grp 31s DC FLAs in parallel are about $1400 before shipping and taxes.

Or 4 x 8D AGM are about $850 (if you have the charging systems to support).

That's right, almost 1/10 the cost. If the 2Vdc batteries last 7 years, and the 8Ds last 2, you are way ahead of the game with the 8Ds, and they recycle easily, any decent battery supplier will accept them and pay out core.

If one wished to put fuses or breakers on each paralleled 12 Vdc battery, they also most certainly can. But the chance of it ever doing anything (other than creating another failure prone connection) for all intents and purposes is, well, zero, about equal to being hit by space junk.

In conclusion, there are few energy storage solutions more effective, more affordable, and more safe, than a house bank of 12 Vdc marine Deep Cycle FLA batteries in parallel.

[john61ct]

Originally Posted by ramblinrod

It is dependant on an electronic BMS to prevent it from running amuck

False, if you mean the proprietary "integrated solution$".

Overvoltage and low temperature cutoffs are critical to protect the bank from expensive damage are all that's different from LA to LFP.

Otherwise normal safe wiring practices and circuit protection are all that's required, again same as any large bank.

Originally Posted by ramblinrod

as we all know, battery management systems can fail.

Same with LA-oriented infrastructure. Just use multiple layers of protection, can use alarms, make things as failsafe as you like.

A responsible owner is keeping a watchful eye as part of regular maintenance in any case.

Yes high amp flows are an issue to account for in the design, but that is independent of chemistry.

OT: Anyone know how to properly mount a 1000A shunt in minimum space? Being on negative does it need to be covered?

[john61ct]

Originally Posted by ramblinrod

in my experience East Penn 12 Vdc Marine Deep Cycle batteries are pretty good. What they may not have in specified "lab cycles", they make in economy. In practice, one gets about the best deep cycle / dollar obtainable, in my experience.

Who manufactures the "Duracell" labeled GC2s available from Sam's or B+ for <$180 per 12V 200+AH.

Yes, barely meets many definitions of true deep cycling lifetime specs, but I'd **really love** to see the same value $/AH in 12V units (links or at least specific model #s please)

And true, East Penn is trustworthy, but the label "marine deep cycle" from 99% of the 12v brands out there in consumer retail channels is an outright fraud AFAIC.

[john61ct]

Originally Posted by ramblinrod

Mastervolt one of the leading marine power management manufacturers.

Completely misleading basis for comparison. Not a battery manufacturer, and most famous in NA markets for being crazy overpriced.

With Concorde, USB, Enersys, Northstar, all the way up to Rolls, yes of course you can spend big bucks for higher quality, and many owners consider that extra expense a worthwhile investment.

In the mid-tier Crown, Trojan, USB, Superior, Deka conversation you're getting a bit shorter lifetimes, maybe lower CAR, but still excellent value for money.

Are there other marques worth considering for true deep cycling use cases?

Yes we are talking a small segment of the "total market" in boats on the water, but that is the niche this forum addresses.

Do you honestly think these vendors sell most of their unit volumes in 12V form factors?

[ramblinrod]

Originally Posted by john61ct

False, if you mean the proprietary "integrated solution$".

Overvoltage and low temperature cutoffs are critical to protect the bank from expensive damage are all that's different from LA to LFP.

Otherwise normal safe wiring practices and circuit protection are all that's required, again same as any large bank.


Same with LA-oriented infrastructure. Just use multiple layers of protection, can use alarms, make things as failsafe as you like.

BS.

Show me one FLA battery which relies on electronic circuitry to prevent it from melting down.

Just one please.

Just show me one.

One.

Now show me on LifePo4, that doesn't.

Just one please.

Just show me one.

One.

Can't do it?

I didn't think so.

In conclusion, there are few energy storage solutions more effective, more affordable, and more safe, than a house bank of 12 Vdc marine Deep Cycle FLA batteries in parallel.

[ramblinrod]

Originally Posted by john61ct

Who manufactures the "Duracell" labeled GC2s available from Sam's or B+ for <$180 per 12V 200+AH.

Yes, barely meets many definitions of true deep cycling lifetime specs, but I'd **really love** to see the same value $/AH in 12V units (links or at least specific model #s please)

And true, East Penn is trustworthy, but the label "marine deep cycle" from 99% of the 12v brands out there in consumer retail channels is an outright fraud AFAIC.

Deka 8D, 12 Vdc @ 245 A-hrs.

But in my opinion, though a bit more expensive (2 x $112.50 = $225), 2 x 12 Vdc Grp 31 DCs is a wiser solution, for lower unit weight and easy handling, and inherent redundancy.

Again if one of the 2 x 6 Vdc golf car batteries you're suggesting goes down, ya got nuthin'. With 2 x Grp 31's, 50% capacity remains, until house bank repairs can be effected (and much more easily).

In conclusion, there are few energy storage solutions more effective, more affordable, and more safe, than a house bank of 12 Vdc marine Deep Cycle FLA batteries in parallel.

[ramblinrod]

Originally Posted by john61ct

In the mid-tier Crown, Trojan, USB, Superior, Deka conversation you're getting a bit shorter lifetimes, maybe lower CAR, but still excellent value for money.

So now 4 times the money for 2Vdc batteries alone, for around twice the life expectancy.

And of course, all of the other hassles and costly additions previously posted.

This is better value, how?

In conclusion, there are few energy storage solutions more effective, more affordable, and more safe, than a house bank of 12 Vdc marine Deep Cycle FLA batteries in parallel.

[TeddyDiver]

Originally Posted by ramblinrod

Here's a link to a 2Vdc Gel 1000 A-hr battery distributed by Mastervolt one of the leading marine power management manufacturers.

https://www.invertersupply.com/index...oducts_id=3184

That's right, over $1000 each. So for a single series string of 6 batteries to produce 12 Vdc, we're talking about $6000. Throw in a couple spares, and we're talking $8000, plus shipping, plus taxes.

Or if one wishes to purchase and install an expensive DC-DC converter, so if a 2 Vdc battery in a series string goes down they can still produce 12 Vdc, they most certainly can. Here's a link to the highest output model produced by Mastervolt...

https://www.invertersupply.com/index...oducts_id=3210

That's right, if relying on this to run house loads from a 12 Vdc, 1000 A-hr bank of 2 Vdc batteries in series, for their $580 (plus shipping, plus installation wiring, and labour if hired, plus taxes) they get a whopping 20A output. About enough to run a fridge, autohelm, and VHF on a typical cruising boat. Anything more, and it just doesn't have the guts.

Now remember, this 20A output is on a vessel that "needs" a 1000 A-hr bank, a pretty energy hungry beast.

1# Wouldn't pay either such prices when there are high quality 1000Ah OPzS batteries 400€ / pc, 2400€ for six. Which by the way can deliver 200A at 5h rate and even more. Wan't to be cheap Chinese sell them $260 a piece..
DC-DC converters you get from 20€ but of course there are more expensive ones but nobody is forcing to buy the $600 one. As you said 20A is all you need, and you get 10 of them with peanuts. What's best and the only reason to get a DC-DC converter is to isolate the electronics from the charging currents and other "dirty" current. The ability to run things with lower battery bank voltage is just a bonus.
Inverter is needed anyway, that's not related what batteries feed it..

BR Teddy

[john61ct]

I have never thought 2V suits anything but the hugest banks.

All banks have fuses.

The extra circuitry for LFP has nothing to do with life-threatening danger, just protection of the investment.

As I said choosing to pay more for better quality is a rational choice, the variables are the owners priorities.

I don't find any local suppliers for the 12V units you mention, shipping would almost double the pricing compared to the East Penn 6V, which are available within 30 min drive of 90% of the US population.

[ramblinrod]

Originally Posted by john61ct

I have never thought 2V suits anything but the hugest banks.

All banks have fuses.

The extra circuitry for LFP has nothing to do with life-threatening danger, just protection of the investment.

As I said choosing to pay more for better quality is a rational choice, the variables are the owners priorities.

I don't find any local suppliers for the 12V units you mention, shipping would almost double the pricing compared to the East Penn 6V, which are available within 30 min drive of 90% of the US population.

Is that so? Where do you live?

[GrowleyMonster]

Rod, that price for the 20a dc/dc converter is terrible. My two 10a units cost about $18/ea as I recall. Kelly sells a 35a unit for $129.

[ramblinrod]

Originally Posted by GrowleyMonster

Rod, that price for the 20a dc/dc converter is terrible. My two 10a units cost about $18/ea as I recall. Kelly sells a 35a unit for $129.

Now wait just a minute. I've been responding to those who feel 12 Vdc batteries in parallel is patently unsafe, and certainly not suitable for the middle of the ocean.

Certainly those people wouldn't entrust their ability to run house loads in the event of a 2Vdc battery failure to in unknown eBay vendor from China to provide a DC-DC converter for $18, that is neither marine grade, nor marine electrical standards compliant?

It can't go both ways at the same time. We're either talking quality and reliabilty from a reputable source you can rely on for your life, or cheap #^#%# from who knows where, that hopefully works when needed.

[TeddyDiver]

Originally Posted by ramblinrod

Now wait just a minute. I've been responding to those who feel 12 Vdc batteries in parallel is patently unsafe, and certainly not suitable for the middle of the ocean.

Certainly those people wouldn't entrust their ability to run house loads in the event of a 2Vdc battery failure to in unknown eBay vendor from China to provide a DC-DC converter for $18, that is neither marine grade, nor marine electrical standards compliant?

It can't go both ways at the same time. We're either talking quality and reliabilty from a reputable source you can rely on for your life, or cheap #^#%# from who knows where, that hopefully works when needed.

Don't be naive, nobody saying a couple of batteries parallel are patently unsafe. A bit increased risk, yes. But every battery more in parallel increases the risk and also the consequences if something goes south.
Let's compare presuming the quality of batteries is the same. Series 6 x 2v cells and a one 12v batteries have a risk factor of 1/500 for internal short. Two 12v parallel is 2/500 and six 6/500. You decide what risk you can take and live with it, no problemo.
There are also other risks to consider with paralled strings as uneven resistance which reduces the battery life of all batteries in parallel and then the probality of a fail increases to ^2 with every additional string in parallel.

BR Teddy