# Battery Discharge test for Maintanence Free lead acid battery Requirement



## mdchinku (Sep 17, 2016)

Hi all,
Iam second mate working onboard tankers and next month we are due to conduct discharge test of GMDSS battery. We have maintenance free lead acid batteries onboard, Can somebody guide if discharge test is to be conducted for such batteries and if so How??


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## John Rogers (May 11, 2004)

mdchinku said:


> Hi all,
> Iam second mate working onboard tankers and next month we are due to conduct discharge test of GMDSS battery. We have maintenance free lead acid batteries onboard, Can somebody guide if discharge test is to be conducted for such batteries and if so How??


I have the same battery on my back-up generator not much to do for maint, I have to replace them every four years or it won't turn the engine over.


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## Troppo (Feb 18, 2010)

The radio surveyor will (should) have a discharge tester with him. He will use that to check the batteries...


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## Ian Hay (May 26, 2013)

There is a thread on here that discusses the "merits" (or otherwise) of GMDSS,there is reference to battery discharge tests. http://www.shipsnostalgia.com/showthread.php?t=13155


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## Bill.B (Oct 19, 2013)

When I do a GMDSS survey the first thing that happens is that the AC breakers get switched off and everything should run on batteries. That includes the GPS that feeds all GMDSS equipment. Depending on whether she is a 1 hour vessel or a 6 hour vessel is how long they stay on battery. During the test the equipment is run, tuned, operated, transmitted as near as possible to simulate the specified load that is calculated that the batteries should meet.
Hope that helps


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## Varley (Oct 1, 2006)

In the likely event you have only one battery then you can only carry out an endurance test when you are in port. Battery to be fully charged when you are sea .


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## Troppo (Feb 18, 2010)

You should be regularly turning off the mains breakers and running the GMDSS equipment on batteries....at least once a month,


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## Varley (Oct 1, 2006)

The only fluid for which religion is in any way relevant in the determination of its specific gravity is in a font with the possible exception of embalming fluid.

Be careful should you replace sealed cells with vented ones as the space/facility must be certified for their siting.


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## Troppo (Feb 18, 2010)

This thread is a magnificent example of what is wrong with the GMDSS.


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## Harry Grainger (Feb 28, 2007)

#9 What about communion wine ?


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## trotterdotpom (Apr 29, 2005)

R651400 said:


> Or employ a real Radio/Electronics Officer who would be fully conversant with the expression Ampere-Hour Capacity whose first job would be to change the sealed batteries to the earlier unsealed type and complete with hydrometer religiously check the specific gravity of the sulphuric acid electrolyte plus making sure every cell was gassing freely.


What and pay for them himself?

John T


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## trotterdotpom (Apr 29, 2005)

R651400 said:


> #9.. Where were your freely gassing emergency batteries with SSM. Your cabin?


Ahem, David didn't work for SSM, he worked for Denholms - a common mistake.

John T


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## trotterdotpom (Apr 29, 2005)

Bill.B said:


> When I do a GMDSS survey the first thing that happens is that the AC breakers get switched off and everything should run on batteries. That includes the GPS that feeds all GMDSS equipment. Depending on whether she is a 1 hour vessel or a 6 hour vessel is how long they stay on battery. During the test the equipment is run, tuned, operated, transmitted as near as possible to simulate the specified load that is calculated that the batteries should meet.
> Hope that helps


What's the difference between a 1 hour vessel and a 6 hour vessel? Most ships can't get all that far in 6 hours.

John T


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## vasco (Dec 27, 2007)

Troppo said:


> This thread is a magnificent example of what is wrong with the GMDSS.


or the training. I was given no training in the maintenace of batteries during my GMDSS course, hence although I never had any problems, I was self taught with a a bit of help from others.

One vessel I was on recently had the 2/E checking them. He seemed very surprised when they failed. They were not sealed and all he did was check the voltage across the terminals. Well experienced and otherwise a very competent fellow. His batteries were perfect.


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## trotterdotpom (Apr 29, 2005)

vasco said:


> or the training. I was given no training in the maintenace of batteries during my GMDSS course, hence although I never had any problems, I was self taught with a a bit of help from others.
> 
> One vessel I was on recently had the 2/E checking them. He seemed very surprised when they failed. They were not sealed and all he did was check the voltage across the terminals. Well experienced and otherwise a very competent fellow. His batteries were perfect.


The voltage means nothing. The specific gravity tells all ... and the level of the electrolyte helps.

Gotta go, my specific gravity is over the top.

John T


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## Varley (Oct 1, 2006)

trotterdotpom said:


> What's the difference between a 1 hour vessel and a 6 hour vessel? Most ships can't get all that far in 6 hours.
> 
> John T


1 hour permitted if the ship's Emergency source of electrical power complies with SOLAS II 1/42 or 43 and 6 hours if not.


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## Varley (Oct 1, 2006)

trotterdotpom said:


> The voltage means nothing. The specific gravity tells all ... and the level of the electrolyte helps.
> 
> Gotta go, my specific gravity is over the top.
> 
> John T


Ah, but. It is not impossible that the reserve source is NiCad where it is the voltage that indicates the remaining charge. The SG only tells you when the electrolyte needs replacing.

(I do love nit-picking, John T!)

NiCad should normally and easily last the life of the vessel however as it will be a superintendent of plumbing who gets to manage these things and they know naught of CO2 'poisoning' of potassium hydroxide solution (as it is not used in boilers or other pig-iron items) they will assume an under-performing battery needs replacing. They will price a replacement and, as lead acid is less expensive, the perfectly good NiCads will be stripped out and voila, lead acid rules.

Another fairly frequent arrest that had to be made were innocent attempts to correct buggered vented batteries with fresh acid.

#17 - your correction is of course true but only because R651400 ommitted a "THE" in front of Scottish ship management. That would have made it just fine.


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## Varley (Oct 1, 2006)

Harry Grainger said:


> #9 What about communion wine ?


Hi, Harry. Any chance you will make that trip across to Peel (I can still just about make it but maybe not all on foot as I used to)?

I love the idea of a battery using communion wine as electrolyte, I am quite sure I could have got used to drinking from hydrometer. Perhaps there is such a thing and the knowledge has been kept from jolly Jack. For just that obvious reason.


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## Varley (Oct 1, 2006)

R651400 said:


> #15 Applaud your obsequiousness but in reality does any of us R/O neanderthals actually give a monkey's fanny who our ex employers were?


When gassing on SN I suppose.

If you were accept that it is only an electrical type with tested and certificated competence onboard instead of a Radio Electronics Officer I could agree all the way. It has ever been absurd to have two electrical demarcated disciplines on the average ship, just as absurd as it is that generally the more important of those came USUALLY without proper qualifications other than 'by experience'.


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## richardwakeley (Jan 4, 2010)

Just to be a bit boring and spoil all the fun, but I actually do know the regulations - or supposed to know them as I am still a radio surveyor.

Maintenance free (sealed) batteries have to be given an annual discharge test, in port, to confirm their capacity. This is additional to the regular on load voltage tests. 

To give advice to the 2nd Mate who started this thread, just switch off the AC power for the GMDSS gear, including the battery charger, and make sure the gear is all switched on and running on battery. Make sure to log your test in the GMDSS log book, as the surveyor needs to see it has been done within the past 12 months when the next Safety Radio Survey is done.

By the way, the majority of new buildings now have sealed maintenance free batteries. Many ships don't have electricians, and maintenance will be in the care of the 3rd Eng or 2nd Mate.

To answer another question. A 1-hour ship is one with an emergency generator and the GMDSS battery is only required to power the gear for 1hour. A 6-hour ship is one without emergency gennie. There were quite a few of these when we did the GMDSS retrofitting in the 90s, but practically none remain now. The SOLAS regs for an emergency generator outside the engine room came in around 1982, so those ships have long been scrapped.

Can't think of a joke right now - will have to leave it for Trots.

Richard


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## Troppo (Feb 18, 2010)

R651400 said:


> Now we are on the same "onde."
> What really disturbs me on #1 is originator is a 2nd mate screaming for advice on lead acid batteries and their practice from SN?
> Mon Dieu!
> At least he is on a tanker with no more than 10 souls max but if out of kilter on the high seas with no GMDSS? The mind boggles...
> ...



Exactly.

Cruise ships never have problems....no...


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## angad305 (Sep 22, 2016)

*Please read what solas has to say !*

This thread is a disaster. please read from here..

https://cultofsea.com/gmdss/gmdss-batteries-requirements/

I hope this helps//and yea
1. 1hr gmdss backup for ships with electrical emergency power source
2. 6hrs gmdss backup for ships with NO electrical emergency power source


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## Troppo (Feb 18, 2010)

SOLAS IV....who would have guessed.....amazing.


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## Varley (Oct 1, 2006)

I don't think there are any SOLAS vessels without any emergency source of electrical power - Ch II-1 part D.

The difference is whether it fully complies with the Post 1986 (94) amendments. In which case 1 hour endurance reserve source is allowed. Otherwise 6 hours. Although I have never seen or heard of a non secondary cell reserve source another solution is not excluded (whether any would get approval is another matter) Strangely if the reserve source is not a "battery or batteries", which must be tested every 12 months when the vessel is not at sea, SOLAS would appear to require no testing of it. 

I have not kept a copy of the earlier consolidated version but from memory the differences WRT ships emergency source were about siting, automatic starting (if by generator), automatic connection and what had to be supplied by it.


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## Troppo (Feb 18, 2010)

It would be very rare to find a "6hr" ship these days.

I remember of 50-odd Aussie GMDSS ships in the 1990's, there was only one...

Surveying it was always time consuming, as after you had completed the survey, you had to sit and wait for the discharge test to finish.

Nice if the sun was out...


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## richardwakeley (Jan 4, 2010)

Can't remember the last time I surveyed a 6 hour ship. But there were a lot when we did the GMDSS retrofits in the 90s. For instance, the Gearbulk '2nd Generation' like Falcon Arrow, built in late 70s, only had Main AC power.
We don't generally do a full discharge test of the reserve battery during a survey here. My own habit is to knock off the AC as soon as I start the checking, then leave the MF/HF testing to last. A DSC call, or SSB on tone, will then show the state of the battery. Nearly all are maintenance-free now, except a lot of Japanese builds still using the very reliable and long lasting (if properly maintained) SS-200.

Further to some of the regs quoted by you guys above. There are a lot of things allowed by the regs which are not really in common practice. For instance the ship's 'General Battery' could be used as the 'Emergency source' for radio, but it would need DC-DC change-over with the 'Reserve Source' GMDSS battery, and also is required to supply power for 18 hours on cargo ships. Since the General Battery is usually just a 200AH battery identical to the GMDSS one, this would not really be practical.


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## angad305 (Sep 22, 2016)

any ship which has a emergency back, though in your case on failure of main and emergency power source!! yes will give only an hour backup


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## richardwakeley (Jan 4, 2010)

G'day R65,

In practice it will be more like 6 hours, or more. The majority of ships have a 200AH reserve battery for GMDSS, which is much more than required to meet the calculations for one hour. And of course it depends on the actual transmit/receive time ratio of the equipment they decide to use in emergency, which is very unlikely to be NBDP.


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## Engine Serang 2 (Nov 24, 2020)

Elon Musk would sort out all this Sparky/Lecky squabbling. As Mr Musk says, regulations are only for the little people.


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## Varley (Oct 1, 2006)

Kind of you to to add your penny's worth E-S. Would it help if I drew a parallel with the 'first start arrangement'? As I also don't believe in the 'little people' their rules and lack of them are irrelevant. Were they to exist, it is the other inhabitants of their homeland that patently are wanting for rules or, at least, the observance of those extant.


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## Varley (Oct 1, 2006)

richardwakeley said:


> G'day R65,
> 
> In practice it will be more like 6 hours, or more. The majority of ships have a 200AH reserve battery for GMDSS, which is much more than required to meet the calculations for one hour. And of course it depends on the actual transmit/receive time ratio of the equipment they decide to use in emergency, which is very unlikely to be NBDP.


Richard,

At the outset I tried to get a two battery supply approved but this was rejected on the grounds that GMDSS training would not include battery management of this outrageous sophistication. The two battery outfit MIMCO standard was to enable the batteries to be exercised in turn. With the requirement for the one and only GMDSS battery to be fully charged when at sea and the impracticality of a GMDSS operator to do so while working cargo in port it left only the survey to confirm the effective duration of the GMDSS battery.

Now you tell me you didn't do that?

As with other features that are never stress tested it is usual for their shortcomings to be revealed only when they are needed. Emergency generators and their controls don't give any lie to that.

David V


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## J. Davies (Dec 29, 2010)

Hello again Mr. Varley

Last year I was lecky on board a small expedition ship sailing all over the place. We stopped in St Johns, Newfoundland, a wonderful run ashore by the way, lovely people and excellent beer.
A nice lady from ABS came aboard and wanted to check the GMDSS batteries and asked how we maintained and tested them. I'm an old sparky so I told her how I used a hydrometer on the two banks of 200 AH batteries, and put the readings in the log. I explained that the old fashioned non maintenance-free batteries were best cos they withstood heat and freezing better than to gel ones with the silly green eyes that say "I'm OK." I told her how I topped up the batteries when required. The two battery sets were charged from two supplies; main and emergency. The DC went through hefty diode bridges to the load. Quite neat I thought. Then every week we would turn off the supplies and check the terminal voltage after a few bursts of SSB or DSC. Usually start at 27 VDC and drop to 24 VDC after an hour. Any less and change the batteries _tout suit_.
She seemed quite impressed. 
I wonder how ships with no leckies check the batteries. I suppose the shore based maintenance sticker on the bulkhead covers that. All the best.


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## Varley (Oct 1, 2006)

We did not have that many ABS classed vessels and none that I had truck on the GMDSS front. I am refreshingly surprised that they allowed two batteries. It was not only class where I encountered that I prohibition but also UK and IoM flags. The process of changing over banks and testing endurance either had to be a feature of the GMDSS operators' certification, which it wasn't or it would not be permitted. Also even if the arrangement became permitted allowing either to be anything less than 'fully charged' would, as it remains, be prohibited.

Port state have quite sufficient power to discover and discipline vessels with deficient radio stations. the GMDSS maintenance certificate in my view was a weak excuse to make the option of an onboard maintainer unviable from the outset (not that I am sure it would have been feasible with the repairabilty of such kit). It is merely an administrative burden for managers as it requires renewal annually to the irritation of suppliers prepared to offer the 'service' free to a regular client.

(I preferred NiCads myself but on those few vessels where they had been the original installation they were often changed for PbSO4 as too few realised that renewal of electrolyte was most probably all that was needed. I think they may have had a slightly less good low temperature performance).


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## Engine Serang 2 (Nov 24, 2020)

Kind of you to to add your penny's worth E-S. 

I'm a bit upset by the above comment.
I thought I'd given six penn'orth, such is life.
I've always thought that the emergency batteries were tucked away in the least accessible spot on the ship and the words "Maintenance Free" was a godsend for everyone from the Super downwards. And if a Radio Surveyor commented then the Agent was sent away for two lorry batteries. And the cycle starts again.

My attitude towards emergency batteries was driven by talking to and reading about the technical crew of Porpoise and Oberon Class submarines. The operation and maintenance of their batteries showed how it should be done, no compromise but such procedures never found favour in the Merch.
The emergency batteries are there to save all our lives, sometimes forgotten.

And don't get me started on BOT Sports. Once again look at yesterdays papers, 
*Two Seriously Injured in Lifeboat Drill Accident in Vancouver *

When will we ever learn.


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## Varley (Oct 1, 2006)

Sorry E-S. In normal times they would have been worth more but I cannot bandy about sixpences (half crowns even) with our economies so threatened.


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## Engine Serang 2 (Nov 24, 2020)

Lets compromise and settle for a Florin. If our IOM colleague is afraid of exchange controls then a Groat will suffice.
Can't say fairer than that.


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