Simple Battery theory test

Thanks for all the replies - I had tried to keep it simple in the original post, but like all good threads on batteries .... it just aint that simple !!

This morning I have found the following (the batteries having been disconnected from each other yesterday)

No.1 - which had the 25w bulb connected - the bulb was very dim, I took it off and immediately measured the battery voltage at 3.8v. This was after 20hours at 2amps. 5 minutes later I measured it again, and it had recovered to 9.4v.

No. 2 - I had left this connected to the system and last evening turned on a combination of lights to draw 5,3amps which is the 20hour rate of 105Ah. This morning, after 14hours, I would have expected the voltage to still be greater than 10.5 at least. Result? Nothing!! All lights off, not even enough juice to light the Link10 LEDs. Removed all load, and measured voltage at 1.8.

No3 - which I had left totally disconnected from everything, was still up at 12.8v. In light of advice to raise the charging voltage, I have left a bog standard car charger on it, measuring 15.1 volts.

The built in mains charger is a very dumb Newmar (american) which I assume has been there since new in 1996. The website shows that it only goes up to 14.0v at a current of 0.2A. So it is indeed possible that the batteries were not 100% charged. I will go back later today and check the voltage on No3.

It seems the mains charger and batteries are incompatible, so I need to change one or the other. However, the main source of charge would normally be from the alternator and this would never get the batteries to over 15volts.

This would mean that sealed cells are not a suitable choice for boats..... which is odd because there is a lot of them around!
 
Nick we had one of those dumb Newmars which finally got totally dumbed down and dumped! We replaced it with a 40A Sterling (I know....) which has actually proven excellent and is fully adjustable for all battery types plus has a remote control panel where if needs be you can cut the output to 75%/50%/25% to match the AC supply if it is limited power. We actually have wet cell deep cycle batteries which was my choice. We also have a smart alternator regulator from Adverc (actually have two one on each of our two alternators) which uses 14.4/14.6v as the charge voltage in it's program and float volts at 13.4 I think (might be 13.6). However we also have solar panels which are unregulated (my choice, I monitor manually and they are 'off' if we aren't on board} and can go well up on the battery volts periodically using these if we wish which I do maybe 3 or 4 times per year to about 15.5v.

If I were you my choice would be all new wet cell batteries and bigger capacity if possible and you have room, then a modern smart charging system on the alternator and a new smart shore power AC charger. Others will have 101 different options no doubt but that is my two pennyworth!
 
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First, I made sure they were all fully charged - 14.0v being the max from my on board charger, at 0.2A, for 24 hours.

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There maybe some hope for your batteries. I assumed from the above that the charge rate had dropped to 0.2A at 14v not that the charger was only capable of putting out 0.2A.
As others have said get them charged properly and try the test again.
 
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This would mean that sealed cells are not a suitable choice for boats..... which is odd because there is a lot of them around!

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In the case of Delco Freedom and Westerly, that was what we thought. But by never letting the batteries get below 50-60% charge, and bench charging at lay-up, we could make them work.

In this case it may be best to change batteries to new leisure batteries, and keep the current charging system.


Brian
 
Re: Simple Battery theory

I won't compete with all the amps and volts flying around here but I do know that suitable switching/splitting will prevent one tired battery dragging down the others - my domestic died in France with no side effects, so advise improving the installation a.s.a.p.
 
I fear

your charger is not suitable for the Delco Freedom batteries.

They have to be charged at a minimum of 14.5 volts (even the 15.5 suggested), to get them back up to fully charged.

If that charger is the one that has always been used on those batteries it has hastened their end.

As you have nothing to lose, take them individually to a decent charging source with someone who knows what they're doing, to see if they can be revived.

The actions you've taken so far prove nothing.
 
Re: I fear

I now realise that the batteries and charger are incompatible.

However, I am unable to find a marine battery charger on the market which will charge at >14.4volts. Surely I cant be the first person to have this problem.

There is the new Sterling Digital charger which has an option for sealed batteries, but the website doesnt specify the voltage.

I feel a trip to the boat show coming on.
 
Re: I fear

I have one of these Ctek XS7000 which I bought from Merlin [ for about £100].

It has four charging modes; -
13.6 V = Supply only, for connecting stuff to - if you haven' t got a battery handy.
14.4v = Normal, for wet, leisure gel etc.
14.7v = Snowflake, charging in cold weather and AGM types
15.7v = Recondition, does what is says - picked up the knackerd battery on my motorbike.

Worth having a look at I'd have thought - good website.

Paul.
 
Re: I fear

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However, I am unable to find a marine battery charger on the market which will charge at >14.4volts. Surely I cant be the first person to have this problem.

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Which is why we produce mutli stage chargers in 1984, plus all the work on Freedom batteries around 1986, and produced a suitable charger for Westerly.

Sorry they are not available today.

Brian
 
It\'s official!

No matter how hard I try to prove otherwise, the batteries are knackered.

Following advice from halcyon and others, I charged each battery individually up to a charging voltage of over 15.5v using a bog standard car battery charger. Then I left them all to rest for a couple of days, when I returned their voltages were 13.1/2 ish.

Connected my 25w bulb, nothing else, to battery No.1, returned after 18hours, ie 36Ah - voltage on load <4volts, off load, <10v.

Did same to battery number 3, returned after only 6 hours, ie 12Ah, voltage so low I didnt bother making a note of it !!

The one and only thing I havent done is used a megapulse desulphurisation device - I have been using a Sterling equivalent which I am told is rubbish.

Even if I could revive them from here, I wouldnt want to trust them esp crossing the channel, and having the radar scannner working properly when I need it.

Thanks once again for all the help - I learned a lot, if nothing else!
 
Re: It\'s official!

[ QUOTE ]
I learned a lot, if nothing else!

[/ QUOTE ]But we still don't know why they died. Usually that is due to overcharging. If not, then incredibly heavy sulphation. Before investing in new batteries you would be advised to check this out.

One explanation might be that you leave (unintentionally) a load on the batteries when you leave the boat. Often, people wire bits of electronic stuff on the battery side of the Master Switch and that can wreck batteries very quickly.
 
Re: It\'s official!

It could be overcharging due to the 'dumb' charger which I have deliberately left on continuously to keep the charge up, but that only goes to 14.0v max as mentioned earler.

I did leave the instruments turned on for a whole week when she was on a river mooring, and found the batteries flat. I removed the solar panels which you will remember, when we got back to the UK and prefer not to leave the wind genny running unattended for long periods

I now make sure I turn off the master switch as my last final act before dropping in the washboards.

The only device I know that is directly across the batteries is the auto bilge pump, which has no reason to run (he says, touching wood rapidly!)
 
Re: It\'s official!

This is a Freedom battery thing, they do not like being under charged, very few chargers go to the high voltage required, and they do not like being left part charged.

Both happened to these batteries.

As said earlier, this goes back to the mid 1980's when Westerly started fitting Delco Freedom batteries. I went to a Merlin on warrenty work, due to constant flat batteries, owned by Barcley's bank sailing club. It was looking into this and other Westerly battery problems, that we found the odd charge pattern.

We got round it by producing a Westerly battery charger set to 15.5 volt charge and 14.5 volt float. Yachts not fitted with chargers we recommened bench charging at lift-out, and charging batteries as soon as the yellow battery status LED ( below 60% ) came on. Then running engine for 2 hours after the min recharge LED came on.

With this set up we had no more problem with this type of battery.

But as I have said many times, check what your batteries need, not by type, but what the manufacture says, all batteries are not the same.

Brian
 
Re: It\'s official!

Did anybody say that the battery which dropped by 2 volts under load, and then appeared to recover, has a knackered cell?(and needs to meet it's maker)
I don't want to be involved in a Lakesailor incident, but can't see it mentioned above.
 
Re: It\'s official!

Ah-ha. you said you left them charging with a dumb-charger? You probably, possibly 'boiled' them dry!

I know you state that they are sealed for life BUT as they are knackered, it would be worth gently prising open the 'sealed' caps and filling with de-ionised (distilled)(fridge water)(Ironing water) etc.

Nothing to loose really except a couple of days. /forums/images/graemlins/smile.gif
 
Re: It\'s official!

A dumb charger that wont go above 14.0 volts, and that at 0.2A. More like 13.5 effective maximum. As halcyon has pointed out several times, this is not enough for the batteries in question, which look for 15+ charging voltage.

The End.
 
If the batteries have frequently been allowed to drop below 50% you may have simply exhausted them. I found the info below interesting, taken from the Enery web site:

Energy1.jpg


And battery info:

Energy.jpg


The guy at energy gave me some good advice about the three FLA batteries on my boat earlier this year.
 
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