And what's wring with the battery???

[webcraft]

And what\'s wring with the battery???

Whilst experiencing slightly worrying water ingress today the GPS and VHF went off suddenly. Successfully started the engine shortly afterwards on No.1 battery.

Domestic battery showing no charge, engine battery (1) fine. When we got back on the mooring the domestic battery showed 12 volts, but put anything on and it dropped away rapidly to eight or less. Back up to twelve and a wee bittie when no load on it.

The only unusual things that happened today were:

~ electric bilge pump was left on auto and must have been cycling a lot with the water coming in and sloshing about in the bilge. The pump would have been keeping up with it until the battery gave up the ghost. (Had been working fine, had tested the bilge pump on manual earlier)

and

~ there are some wires running through the locker that was full of water, plus a couple of earths onto a seacock.

Are either or both of these likely to be to blame, and is the battery now knackered?? (It's only two years old and has been perfect up 'till now).

- Nick

 

[ccscott49]

Re: And what\'s wring with the battery???

Dont know what happened to it, unless water got on top and shorted it out, but it looks like it may well be knackered!! Get it out and charged up, if it will charge up, then get it load/deep discharge tested. I would also be a bit worried about your seacock, if the battery is earthed to it, for some strange reason, then it may have been carrying some current, which may have damaged it with electrolysis. There is also the cables through the locker, they also may have caused a short, you need to check everything connected to the system. I think it might be prudent to get an expert in.

 

[mikejames]

Re: And what\'s wring with the battery???

I would expect that the battery in question is extremely flat and on its way to knackered and still is.
If you did not switch to charging only the domestic battery as soon as the engine started then the engine battery would have prevented you getting enough voltage to charge a sulphated domestic battery. Sulphation happens with flat batteries.
A sulphated battery will have a higher resistance than a healthy one , so the healthy one takes the current.
I have done this damage twice leaving the VHF on and twice I ended up with a new battery soon after.
A sulphated battery can behave like a good one, complete with convincing voltages except it has a very low capacity, and cant start an engine.

The possibility of electrolysis should be low provided the positive wires are insulated well - in my experience its the positive wire that vanishes when seawater gets into 12v.

 

[webcraft]

Re: And what\'s wrong with the battery???

Get an expert in? When I can post on here? You are joking surely . . .

We never leave the batteries on all/both, so the flat domestic battery isn't going to knacker the engine battery. After engine start we normally leave the bnatteries on 1 for twenty mins then switch over to the domestic battery.

The domestic battery was undoubtablly been flattened by the automatic bilge pump yesterday. It was not fabulously well charged anyway as the wind genny has been off for refurbishment and we don't do a lot of motoring normally.

Thing is, the battery shows about 12V, but put any load on it and it drops off the bottom of the scale on the voltmeter. Does that mean a good charge is likely to fix it, or does it mean it is cream crackered?

(Deep cycle leisure battery, only two years old, normally kept well charged by wind generator, 'condition indicator' thingy shows white = 'battery in good condition but needs charging')

Only looking for opinions really . . . we still have one good battery and I know what precipitated the flattening yesterday.

- Nick

 

[Talbot]

Re: And what\'s wrong with the battery???

IMHO, it sounds like your battey was pretty low, and the water on it has shorted something with a possible cell deterioration. This can only be checked when charged and then use a load tester on it (avaialble at a garage. Notwithstanding this, even if you do resurrect it this time, it will be damaged anyway, so I would just purchase a replacement cause the aggravation caused by a bad battery isnt worth the cost of a replacement.

 

[ccscott49]

Re: And what\'s wrong with the battery???

Get it charged and tested, simple.

 

[tcm]

what\'s that battery plate stuff?

there was a link to some excellent battery stuff, powered, add water, i got some and batteries all fab - it cleans any cack off the plates h2dt or summink like that...

 

[Ships_Cat]

Re: what\'s that battery plate stuff?

"h2dt" = EDTA perhaps?

John

 

[Joe_Cole]

Re: And what\'s wrong with the battery???

[ QUOTE ]

Thing is, the battery shows about 12V, but put any load on it and it drops off the bottom of the scale on the voltmeter. Does that mean a good charge is likely to fix it, or does it mean it is cream crackered?

(- Nick

[/ QUOTE ]

If the battery is only showing 12volts then it is very low indeed. As others have said get it out and try charging it properly.

 

[tcm]

Re: what\'s that battery plate stuff?

yep, that's the stuff .

 

[Stemar]

Re: what\'s that battery plate stuff?

If if you want to stry and salvage the battery, I'd take it home, wash it off with fresh water then dry it - a layer of salt will absorb moisture and allow a surprisingly quick self-discharge.

I'd then put it on an ordinary car-type battery charger until it appears charge - all the cells are bubbling gently under charge, then leave it going for another 24 hours - this will help to clear some of the deterioratio from having been so deeply discharged. Now top it up with distilled water if necessary.

This may get it back, but as some of the others have said, it'll always be suspect.
If any of the cells don't bubble, or bubble a lot more than the others, or need a lot more water to top up, then I'm afraid it's off pass a fistful of fivers to your friendly local battery salesman.

One last thing - charge it up ASAP. After a week sitting in a severely discharged state, it'll be hardly worth bothering with.

 

[webcraft]

Re: discharged battery

I see there has been some misunderstanding here . . . the batteries are in the cockpit locker and at no time was there any water near them . . . the problem is either just deeply discharged 'cos of the automatic bilge pump repeatedly cycling and no charging going on because the batteries were switched to the engine battery, or something to do with wet wires running through the under-bunk space.

Anyway, off to get the battery and charge it up right now. Will report back ASAP.

- Nick

 

[halcyon]

Re: discharged battery

Sounds like a simple case of over use and lack of charge, resulting in sulphation and surface charging. It does not matter if the engine battery is in circuit or not for normal charging, as charge takes the least line of resistance, normally the service battery. If you have a badly sulphated battery then the resistance is high and your charge is low.

Motor more, sail less.


Brian

 

[Stoaty]

Re: discharged battery

Don't faff about. Get a new one. Don't waste your time testing it, it's now unreliable. Get a new one, just go do it.

 

[webcraft]

Re: All wrong . . . nothing the matter with it . . .

Turned out to be a loose earth terminal on the earth strap connecting the two batteries. Once it was tightened and cleaned all is apparently back to normal, with both or either battery charging at about 13.8V from the alternator.

As for the suggestion that the batteries have been spending too long discharged - this is not the case, although they have almost certainly been at a lower average state of charge since the wind generator was taken off the boat - it will be going back on this weekend, and hopefully things will be back to normal. The batteries are only two years old, and have been kept topped up most of the time by the trusty Aerogen.

So - I am glad I didn't listen to all the prophets of doom and rush off and spend £70. And as for the suggestion that I motor more and sail less - well, if I wanted to do that I'd turn stinkie.

I have come to the conclusion that when it comes to boat electrics a little knowledge is a dangerous thing. I have previously been advised to remove my alternator and either have it serviced or throw it away as the red light didn't always go out . . . it now does, who knows why? All I have done is fitted a new dynastart, but as the charging circuit isn't connected and all the charge comes from the alternator this is another bizarre mystery.

What seems to work for me is to tighten things, clean connections, check fuses and spray with silicon spray. It is amazing how often this brings things back to normal. Of course, finding the correct bit to clean, spray or jiggle may take some time, but it can save a lot of money thrown at a hasty diagnosis . . .

All IMHO, and in no way deprecating everyone's advice - but it is a black art, isn't it? I think the only way round it is to strip every wire out of the boat and do a total rewire yourself - then you might just understand half of what happens.

- Nick

 

[Guest]

An example of NOT calling in experts !

Last winter we had -32 C for a few days and my Truck batterys FROZE ..... solid. They had been left stupidly flat and of course when the frost came - the lower density of the battery electrolyte allowed it to freeze.
The battery cases were swollen and distorted .... all who saw them said - Get new ones !! Have you seen the price of HD 180a/Hr Truck batterys ???? Two of 'em !

Anyway we brought them into the house, left them for 4 days to thaw out .... actually took about 6 days !! But introduced charger on 5th day. Took 2 weeks to charge them up ... giving them alternate days on charger .....

My thought was - trucks waiting repair anyway .... so lets try it. Spring came and repair guys arrived for truck.... batterys were handed over .... 2 weeks later get call from repairers - trucks ready ... so I ask what about the batterys ... any problem ? Answer - no been fine why ?

I don't say that every battery will do this - and this was extreme !! But I also know that some batterys can do with a real boost charge or like in these - a careful staged charge ....

Now an expert is going to explain what happened here ... and I for one will be extremely interested to know !??? /forums/images/graemlins/tongue.gif

 

[Guest]

Yee HAH !! Right on - 101% with you there !!

As many know - I am not one of the grab the cheque book people and I'm not surprised that all it was a poor connection.

How many times in the old days did people say about earths on cars etc. led to poor starting etc. etc.

In Newport - my engine refused to turn over couple of year back .... I looked and couldn't find it ... tried evrything .... called in engineer .... £45 later .... yep you guessed it - poor contact between cables to starter terminals .....

Glad you found the real answer ..... !!

/forums/images/graemlins/cool.gif

 

[Stoaty]

Re: Yee HAH !! Right on - 101% with you there !!

Once you have seriously discharged a lead acid battery, whether flooded, Gel or AGM. Then you have seriously shortened it's life. It may charge up fine today, next week, next month, but it won't be long before it fails. It is unreliable now.

Have a read of this on the sterling power site.

http://www.sterling-power.com/htm/faqmain.htm

 

[webcraft]

Re: But it wasn\'t . . .

seriously discharged . . .

Voltage was 12.43 minimum, now back up to 12.7 or thereabouts and looking good.

So sorry Stoaty you pessimistic mustelid, it's fine and I ain't going to worry about it no more . . . bought an Orkney pilot and some sail repair tape nstead today. If I worried about everything that might fail on Fairwinds we'd never go sailing!

Remember, Sterling Power want to sell you things!

- Nick

 

[Joe_Cole]

Re: But it wasn\'t . . .

I can't see why you bother to ask for views if you are going to respond like that or dismiss them as "prophets of doom and gloom". They are only trying to help, and basing their comments on what you have said.
You did say that the voltage was 12volts. You are now saying it was 12.43. That's a big difference for a battery.