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Old 03-02-2014, 21:40   #16
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Re: Danger Warning ACR's

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Originally Posted by sabray View Post
In this system where is the failure.
1 the owner left the boat with the charge system on. 2 the system was built with inadequate fuse and install was poor. 3 acr circuits caused the failure.
None of the above, and all of the above.

1. Many boats are left with an inverter/charger float charging the bats.

2. Fuses would not of changed the outcome.

3. ACR, did not cause the fault, that is not what I reported.

The final answer is the ACR lacks a fault tolerance into a low value short into a 2nd battery. This causes heat to be generated, until the fault causes 1. the battery to over heat/over charge, or 2. the faulted battery to either explode or dead short.

It's not until there is an over current, or dead short, do the fuses come into play.

Lloyd
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Old 03-02-2014, 21:44   #17
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Re: Danger Warning ACR's

So why is the warning directed at acr if that is not what failed?
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Old 03-02-2014, 21:57   #18
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Re: Danger Warning ACR's

it was battery failure. and would have happened if you had separate engine and house chargers and no acr as well. say a 40a charger hooked to the engine batteries and the charger / inverter to the house, with no acr. which is a common setup. it would have been pumping 40a in and likely done the same thing.

if it didn't happen at the dock with the smaller charger or an echo charger. it still would have blown up at sea from the alternators... I would rather it blow up at the dock. so if anything the acr saved him


every boat sits at the dock 24/7 365 with ac and chargers on. this is not the problem for those saying it is...
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Old 03-02-2014, 23:28   #19
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Re: Danger Warning ACR's

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it was battery failure. and would have happened if you had separate engine and house chargers and no acr as well.
That's why I wont install any charge source, that isn't ...Temp compensated


Quote:
say a 40a charger hooked to the engine batteries and the charger / inverter to the house, with no acr. which is a common setup. it would have been pumping 40a in and likely done the same thing.
The essence of a smart charger, is temp compensation...else it is not a SMART CHARGER.

Quote:
if it didn't happen at the dock with the smaller charger or an echo charger. it still would have blown up at sea from the alternators...

A random charge source, would only fault into a dead short.


Quote:
I would rather it blow up at the dock. so if anything the acr saved him [
The ACR is not random, but by design is 24/7/365. So the ACR is the culprit... at least in this situation.


Quote:
every boat sits at the dock 24/7 365 with ac and chargers on. this is not the problem for those saying it is...
Unless your charge source is not smart?



A SMART Charge Source, by design, is current limited, by temp..., and by design.

Lloyd
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Old 03-02-2014, 23:41   #20
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Re: Danger Warning ACR's

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Originally Posted by sabray View Post
So why is the warning directed at acr if that is not what failed?
+

Gee,
I don't know???

Because it was the driving Circuit,

Nothing else could have generated the force. Except a non temp...compensated charge source.

So.

In answer, an ACR is a fine circuit for random charge sources.

So, an ACR, is good for probably most non-24/7/360's charge sources.

If' you use it for 24/7/360 beware.

Lloyd
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Old 03-02-2014, 23:49   #21
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Re: Danger Warning ACR's

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Originally Posted by FlyingCloud1937 View Post
Proper fusing would not have changed the outcome.

The failure is a result of the battery micro-shorting, and the lack of fault tolerance of an ACR circuit.

Every install of an ACR is subject to the same fault that happened in this instance.

The ACR didn't fail, it did what it was designed to do. =Pass current to the 2nd battery to maintain voltage.

When the second battery fails, current will pass up-to the limits of the ACR/Fusing.

The ACR lacks any knowledge of how hot the 2nd battery is, or the voltage. So it does it's job of passing current, to maintain voltage of the system design. Until there is an open circuit.

Lloyd
What you describe is the flaw of any parallel connected batteries. It's why the top installs only have series-connected batteries.
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Old 04-02-2014, 00:10   #22
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Quote:
Originally Posted by s/v Jedi

What you describe is the flaw of any parallel connected batteries. It's why the top installs only have series-connected batteries.
What difference would that have made? As someone above pointed out, this risk is inherent to any batteries or single battery connected with or without an ACR or any other device, series, or parallel, so long as the batts are float charged for weeks with no one on board.

The shorted cell suddenly turns the battery into an 11 volt one, the charger senses the need for charging, pumps in the amps, boom.

It happened to me a couple of years ago. I left the boat in Cowes on shore power for a month, arrived on board to the smell of sulphuric acid. Miraculously, the cell must have just shorted just prior to my arrival, hence no fire and no explosion, thank Neptune.

A temperature sensor won't help unless you have one on every battery (I have 8 in my house bank). It's just one of those things. I think much higher risk with carpy "leisure" batts with weak internal construction and near the end of their lives, like mine were.

I see no logic whatsoever blaming the ACR. Or parallel config of the bank.
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Old 04-02-2014, 00:38   #23
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Re: Danger Warning ACR's

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What difference would that have made? As someone above pointed out, this risk is inherent to any batteries or single battery connected with or without an ACR or any other device, series, or parallel, so long as the batts are float charged for weeks with no one on board.

The shorted cell suddenly turns the battery into an 11 volt one, the charger senses the need for charging, pumps in the amps, boom.

It happened to me a couple of years ago. I left the boat in Cowes on shore power for a month, arrived on board to the smell of sulphuric acid. Miraculously, the cell must have just shorted just prior to my arrival, hence no fire and no explosion, thank Neptune.

A temperature sensor won't help unless you have one on every battery (I have 8 in my house bank). It's just one of those things. I think much higher risk with carpy "leisure" batts with weak internal construction and near the end of their lives, like mine were.

I see no logic whatsoever blaming the ACR. Or parallel config of the bank.
That my friend(and I hope I can call you friend) is the difference of understanding.. electricity.

Dockhead, while I believe you to be a very knowledgeable guy. I think you don't always understand the nuance's.... of E...

Sometimes boats, and systems are not as basic as, they may seem.

Lloyd
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Old 04-02-2014, 01:02   #24
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Re: Danger Warning ACR's

This a potentially interesting post, but like many on these forums goes around in circles with opinions and accusations.

On top of that Jedi adds a post that adds - "top installs only have series-connected batteries" - without fully explaining his words of potential wisdom.

Let me add my thoughts that may need further explaining - by someone with knowledge not just opinions.

Battery compensation on a charger, as I understand it, would lower the voltage as the temperature rises to limit the gassing in the batteries, but not disconnect the charging source, so this is not designed to limit "thermal runaway" on a cell failure. Which "Smart Chargers", either shorepower. alternator or solar have a disconnect feature?

I have learned today, by looking at the manual, that the Balmar Duo-Charge does have this feature - but please FlyingCloud1937 why didn't you add this info in your original post instead of just knocking VSRs? A 1-2-both switch or a Diode Splitter would have caused the same problem.

So the interesting conclusion to this thread - is it better leaving the batteries on solar charge when leaving the boat or shorepower. My shorepower charger at least has much more "smartness" than my Morningstar solar - it boosts the charge every 7 days to stir up the batteries. I set my shorepower charger to lower voltages and much shorter absorption times during the winter layup. You could do the same with a good solar controller - and cover 3/4 of the panels to provide much lower output. My starter battery has a 5 watt solar panel to keep that happy.

Is there really any way to stop thermal runaway on a faulty house batterie?????
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Old 04-02-2014, 01:24   #25
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Re: Danger Warning ACR's

Quote:
Originally Posted by FlyingCloud1937 View Post
That my friend(and I hope I can call you friend) is the difference of understanding.. electricity.

Dockhead, while I believe you to be a very knowledgeable guy. I think you don't always understand the nuance's.... of E...

Sometimes boats, and systems are not as basic as, they may seem.

Lloyd
Hi Lloyd: I am always eager to learn something new, and anyway never claimed to be an expert in electricity.

So if the ACR contributes something to this problem which wouldn't exist anyway -- I will be very happy to learn about it. At this point, I don't see it. How would the situation be any different with a shorted cell and no ACR? The charger is still going to be pumping in the amps, not so? Causing the same melt down?
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Old 04-02-2014, 01:31   #26
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Re: Danger Warning ACR's

All I have to say is go to my bottom line.

My original post:
Quote:
Originally Posted by FlyingCloud1937 View Post
Well as of today I have a new reason to continue not installing Automatic Charge Relays.

This morning I went to a call for dead starter battery, an 8-D Dyno 12volt. As soon as I opened the ER hatch, I new what I was going to find. Just by the the smell of Sulfuric Acid.

A shorted cell in the battery caused the battery to explode. The battery was contained in a home made plywood box, that wasn't liquid tight, nor did it have a cover. So acid is everywhere.

Now about my warning.
The battery was being charged by an Automatic Charge Relay. I surmise that one cell in the battery began micro shorting causing undue current to flow, which generated excess heat, and caused further degradation until we now had an 11 volt nominal battery, which caused more current to flow, until the battery blew.

That's exactly why I have always installed the Balmar Due-Charge with temp sensing.

Lloyd
I laid the Gauntlet, and I am still here.

It wasn't gun then run!!




Quote:
Originally Posted by sailinglegend View Post
This a potentially interesting post, but like many on these forums goes around in circles with opinions and accusations.

On top of that Jedi adds a post that adds - "top installs only have series-connected batteries" - without fully explaining his words of potential wisdom.

Let me add my thoughts that may need further explaining - by someone with knowledge not just opinions.

Battery compensation on a charger, as I understand it, would lower the voltage as the temperature rises to limit the gassing in the batteries, but not disconnect the charging source, so this is not designed to limit "thermal runaway" on a cell failure. Which "Smart Chargers", either shorepower. alternator or solar have a disconnect feature?

I have learned today, by looking at the manual, that the Balmar Duo-Charge does have this feature - but please FlyingCloud1937 why didn't you add this info in your original post instead of just knocking VSRs? A 1-2-both switch or a Diode Splitter would have caused the same problem.

So the interesting conclusion to this thread - is it better leaving the batteries on solar charge when leaving the boat or shorepower. My shorepower charger at least has much more "smartness" than my Morningstar solar - it boosts the charge every 7 days to stir up the batteries. I set my shorepower charger to lower voltages and much shorter absorption times during the winter layup. You could do the same with a good solar controller - and cover 3/4 of the panels to provide much lower output. My starter battery has a 5 watt solar panel to keep that happy.

Is there really any way to stop thermal runaway on a faulty house batterie?????
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Old 04-02-2014, 01:39   #27
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Re: Danger Warning ACR's

As I have always said...........

Temp... Compensation.....

Or called current limit... voltage limit.

A LA can only run a way when it has either unlimited Voltage, or unlimited current. The opposite is open circuit.

1.Temp control from the current source can stop the voltage rise.

2. Temp control from the voltage source, can stop over current.

Lloyd

Quote:
Originally Posted by Dockhead View Post
Hi Lloyd: I am always eager to learn something new, and anyway never claimed to be an expert in electricity.

So if the ACR contributes something to this problem which wouldn't exist anyway -- I will be very happy to learn about it. At this point, I don't see it. How would the situation be any different with a shorted cell and no ACR? The charger is still going to be pumping in the amps, not so? Causing the same melt down?
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Old 04-02-2014, 03:14   #28
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Re: Danger Warning ACR's

Quote:
Originally Posted by sailinglegend View Post
I have learned today, by looking at the manual, that the Balmar Duo-Charge does have this feature - but please FlyingCloud1937 why didn't you add this info in your original post instead of just knocking VSRs? A 1-2-both switch or a Diode Splitter would have caused the same problem.
Sail....egend,

When I made this post, It was not my intention to knock ACR's or VSR's, It was my morning report of what I found Today. So then it flashed across my thoughts. That this maybe of interest here!!

So I posted.

Now I find myself defending my post...even though it was only a report of the day's events.

Had I taken time to consider the ramifications, I might of not posted at all.... Or certainly posted, with the for-thought of what might follow.

Take it as you will... for gods sake it's only one report.

Lloyd

Quote:
Originally Posted by sailinglegend View Post
This a potentially interesting post, but like many on these forums goes around in circles with opinions and accusations.

On top of that Jedi adds a post that adds - "top installs only have series-connected batteries" - without fully explaining his words of potential wisdom.

Let me add my thoughts that may need further explaining - by someone with knowledge not just opinions.

Battery compensation on a charger, as I understand it, would lower the voltage as the temperature rises to limit the gassing in the batteries, but not disconnect the charging source, so this is not designed to limit "thermal runaway" on a cell failure. Which "Smart Chargers", either shorepower. alternator or solar have a disconnect feature?

I have learned today, by looking at the manual, that the Balmar Duo-Charge does have this feature - but please FlyingCloud1937 why didn't you add this info in your original post instead of just knocking VSRs? A 1-2-both switch or a Diode Splitter would have caused the same problem.

So the interesting conclusion to this thread - is it better leaving the batteries on solar charge when leaving the boat or shorepower. My shorepower charger at least has much more "smartness" than my Morningstar solar - it boosts the charge every 7 days to stir up the batteries. I set my shorepower charger to lower voltages and much shorter absorption times during the winter layup. You could do the same with a good solar controller - and cover 3/4 of the panels to provide much lower output. My starter battery has a 5 watt solar panel to keep that happy.

Is there really any way to stop thermal runaway on a faulty house batterie?????
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Old 04-02-2014, 03:41   #29
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Re: Danger Warning ACR's

Quote:
Originally Posted by FlyingCloud1937 View Post
As I have always said...........

Temp... Compensation.....

Or called current limit... voltage limit.

A LA can only run a way when it has either unlimited Voltage, or unlimited current. The opposite is open circuit.

1.Temp control from the current source can stop the voltage rise.

2. Temp control from the voltage source, can stop over current.

Lloyd

Still nothing which I can see, which makes the situation any different with or without the ACR.

I had the same problem on my boat, and I don't have any ACR. The battery charger thought the whole bank of 8 batteries needed charging, since one battery had one shorted cell, and pumped in the current, trying to charge it.

When I discovered it, the electrolyte in that battery was boiling and the interior of my boat was full of sulpherous smoke. I arrived just probably an hour before meltdown.

So again -- what difference does the ACR make?

Furthermore, I don't think a lead-acid battery needs "unlimited" current or voltage to melt down (which doesn't exist anyway -- no such thing as "unlimited" current except perhaps during the Big Bang). Melt down, not "run away" -- you need a complete short circuit for that, and not just a shorted cell. To melt down, a lead-acid battery just needs more current than it can accept, enough current to produce more heat than can be dissipated naturally, for long enough to boil off the electrolyte and fuse the plates together, which means a certain amount of current at a certain voltage high enough to overcome the internal resistance of the battery.

This easily happens in a multi-cell battery where one cell is shorted out. It is just like charging a 6v battery with a 12v charger -- you would get exactly the same results -- uncontrolled gassing, then heating up, then boiling electrolyte, then melted plates and possibly a hydrogen explosion . . . don't ask me how I know this . . . BT,DT unfortunately, in my stupid youth once when I didn't realize my motorcycle batt was a 6v . . . boom! My parents were not happy . . .

So again -- what role does the ACR play? I'm still saying -- none. I'm still all ears in case there's something here I don't understand, but so far nothing new . . .
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Old 04-02-2014, 04:12   #30
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Re: Danger Warning ACR's

Quote:
Originally Posted by FlyingCloud1937
As I have always said...........

Temp... Compensation.....

Or called current limit... voltage limit.
Ok, good story.

Let me make THIS very Clear.

A properly temp compensated charge source will reduces the charge voltage, to 3/tenths a volt, less then that of the battery's current acceptance.

No current can flow between the charge source, and the battery at - 3/10's. So no dissipated heat other then what the battery can produce by its self. The bat will self discharge before it can do much damage.

THE ACR, is a current source, based on the fact the house bank will be typically much larger, and is connected to a charge source of it's own needs.

ie Float Charge, the house charger will act as a power supply, increasing current to maintain the Float Voltage at the house bank. The current will rise to the amount needed to float the house bank.

It could mean as much as 100-200 amps depending on the ACR, and fuses.

Now mind you that the current will be determined by the current demand of the parasite battery...ie the starter bank in this case.

The ACR has no temp compensation, nor voltage regulation...it is a CC source, only regulated by the acceptance of parasitic battery bank. Up to the current limit of the fuse.

Lloyd


Quote:
Originally Posted by Dockhead View Post
Still nothing which I can see, which makes the situation any different with or without the ACR.

I had the same problem on my boat, and I don't have any ACR. The battery charger thought the whole bank of 8 batteries needed charging, since one battery had one shorted cell, and pumped in the current, trying to charge it.

When I discovered it, the electrolyte in that battery was boiling and the interior of my boat was full of sulpherous smoke. I arrived just probably an hour before meltdown.

So again -- what difference does the ACR make?

Furthermore, I don't think a lead-acid battery needs "unlimited" current or voltage to melt down (which doesn't exist anyway -- no such thing as "unlimited" current except perhaps during the Big Bang). Melt down, not "run away" -- you need a complete short circuit for that, and not just a shorted cell. To melt down, a lead-acid battery just needs more current than it can accept, enough current to produce more heat than can be dissipated naturally, for long enough to boil off the electrolyte and fuse the plates together, which means a certain amount of current at a certain voltage high enough to overcome the internal resistance of the battery.

This easily happens in a multi-cell battery where one cell is shorted out. It is just like charging a 6v battery with a 12v charger -- you would get exactly the same results -- uncontrolled gassing, then heating up, then boiling electrolyte, then melted plates and possibly a hydrogen explosion . . . don't ask me how I know this . . . BT,DT unfortunately, in my stupid youth once when I didn't realize my motorcycle batt was a 6v . . . boom! My parents were not happy . . .

So again -- what role does the ACR play? I'm still saying -- none. I'm still all ears in case there's something here I don't understand, but so far nothing new . . .
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