Replacing Flooded Leisure Batteries

[EmmaJC]

Hi looking for some advice please. We replaced all 4 leisure batteries a few months ago. Now 2 of them won’t charge even when plugged into a charger in a house. They’re sealed batteries. Can we replace 2 with unsealed batteries? 

[peterboat]

The question that everyone is going to ask is how did you charge them? or not as the case might be, but your answer to the question is you can replace the two duff ones with unsealed ones, but before then, you need to have a good charging regime otherwise you will be buying batteries every couple of months.

[WotEver]

5 minutes ago, peterboat said:

The question that everyone is going to ask is how did you charge them? or not as the case might be, but your answer to the question is you can replace the two duff ones with unsealed ones, but before then, you need to have a good charging regime otherwise you will be buying batteries every couple of months.

Yup, ^^^^^ this. 

[EmmaJC]

Hi thanks for your post. They were being charged on board, but last week we had a starter motor problem and discovered they weren’t charging properly. So we took them to a house to charge from the mains and aren’t getting the green light on two of them. We think the panel that tells us how much they’re charging may be buggered too! 

[peterboat]

I think You need someone who knows about electrics to have a look at things for you before replacing the batteries, Once thats sorted get another two batteries either open or sealed, their isnt really much to choose between them, and often sealed batteries do have removable plugs under a vinyl seal. Good luck

[Alan de Enfield]

45 minutes ago, EmmaJC said:

Hi thanks for your post. They were being charged on board, but last week we had a starter motor problem and discovered they weren’t charging properly.

I'm not sure how a starter motor problem stops batteries being charged - can you explain please.

[MtB]

23 minutes ago, Alan de Enfield said:

I'm not sure how a starter motor problem stops batteries being charged - can you explain please.

 

I suspect flat batteries wouldn't turn the starter motor.

 

 

[MtB]

1 hour ago, EmmaJC said:

Hi looking for some advice please. We replaced all 4 leisure batteries a few months ago. Now 2 of them won’t charge even when plugged into a charger in a house. They’re sealed batteries. Can we replace 2 with unsealed batteries? 

 

Yes you can, but without investigating and finding out why the two batteries failed (and not the other two), I think the two new ones are likely to go the same way pretty promptly.

[Alan de Enfield]

7 hours ago, Mike the Boilerman said:

 

I suspect flat batteries wouldn't turn the starter motor.

 

 

I had considered that but when the OP said the problem was with 2 of the 4 LEISURE batteries it just didn't make sense,

 

1) Leisure batteries would not be powering the starter motor

2) How would 2 out of 4 of the leisure batteries be affected ?

 

My feeling is maybe the starter motor is actually the alternator - but still doesn't make sense, and that 2 of the leisure battery bank have develop internal shorts and are failing to get to full charge.

Hopefully when the OP says "they are not getting to green" she is not using the battery 'magic eye' to determine when the batteries are fully charged,

Edited November 13, 2018 by Alan de Enfield

[Tony Brooks]

It is best to replace batteries as a bank because if on battery develops an internal short circuit and it is not found very swiftly it will discharge the rest of the bank leading to permanent sulphation damage. You can change just the two but you must then monitor the bank closely to ensure any higher charge current for longer than normal or deeper discharge than normal is investigated and rectified. As two of the batteries are now stressed changing just the other two might not be such a good idea but if money is tight then try but Mike may well be proved correct.

 

"We think the panel that tells us how much they’re charging may be buggered too! This rings alarm bells, some panels are well known for encouraging boaters to ruin batteries by long term undercharging so photo or make & model.

 

I am also not sure about the charger. If its a modern small car type then It may "time out" and reduce the charging voltage long before large domestic type batteries are fully charged. Try turning it off and on again every hours or so after an overnight charge. Again, a photo or make and model will get a better reply.

 

 

 

 

[Murflynn]

9 hours ago, EmmaJC said:

Hi looking for some advice please. We replaced all 4 leisure batteries a few months ago. Now 2 of them won’t charge even when plugged into a charger in a house. They’re sealed batteries. Can we replace 2 with unsealed batteries? 

I have found that all the leisure batteries I have bought over the past 10 years (about 12 in total - used for electric traction with minnkota outboard) are actually 'unsealed'.  Even those sold as sealed can be unsealed by stripping off the vinyl labels and levering up the plastic seal lid.  It gives me the chance to maintain electrolyte levels.  AFAIK there is no difference in the batteries.

[MtB]

12 minutes ago, Murflynn said:

I have found that all the leisure batteries I have bought over the past 10 years (about 12 in total - used for electric traction with minnkota outboard) are actually 'unsealed'.  Even those sold as sealed can be unsealed by stripping off the vinyl labels and levering up the plastic seal lid.  It gives me the chance to maintain electrolyte levels.  AFAIK there is no difference in the batteries.

 

I can confirm this is not universally true. My Hankook sealed batts really don’t have any lids at all. Not even any glued down lids.  

[Sea Dog]

10 minutes ago, Murflynn said:

I have found that all the leisure batteries I have bought over the past 10 years (about 12 in total - used for electric traction with minnkota outboard) are actually 'unsealed'.  Even those sold as sealed can be unsealed by stripping off the vinyl labels and levering up the plastic seal lid.  It gives me the chance to maintain electrolyte levels.  AFAIK there is no difference in the batteries.

There is a difference. The proper ones have a vapour recovery system such that when some of the electrolyte evaporates during charging it is condensed and the liquid is restored. This may not be infallible, but it's a lot different to an ordinary battery with a sticker on the top.

[Alan de Enfield]

1 minute ago, Mike the Boilerman said:

 

I can confirm this is not universally true. My Hankook sealed batts really don’t have any lids at all. Not even any glued down lids.  

Agreed.

 

Some of the ones that do have 'caps' are glued / sonic welded down so much that trying to remove them just smashes them.

 

There are sealed batteries and there are SEALED batteries.

[EmmaJC]

Thanks for all your comments. The starter motor won’t be relevant, that has its own battery. It was just when we were investigating that that we noticed the other batteries weren’t fully charged. 

[Naughty Cal]

1 minute ago, EmmaJC said:

Thanks for all your comments. The starter motor won’t be relevant, that has its own battery. It was just when we were investigating that that we noticed the other batteries weren’t fully charged. 

Perhaps best to get someone who knows what they are looking at to have a look.

 

No point replacing the batteries only for them to go the same way as this set.

 

How have you been charging the batteries and for how long each time?

[Momac]

1 hour ago, Alan de Enfield said:

 

1) Leisure batteries would not be powering the starter motor

 

Maybe not.

And no usual.

But possible. 

Edited November 13, 2018 by MartynG
.

[Phil Ambrose]

Ref the magic eye, being of a curious nature I removed one once to find a plastic cage holding a green ball, simple as that.

Phil 

[Alan de Enfield]

4 minutes ago, MartynG said:

Maybe not.

And no usual.

But possible. 

Of course anything is possible - there is no 'standard' boat, but, explain how  two batteries out of a bank of 4 are flat and the other two aren't.

In my mind it can only be that those 2 have internal shorts, and that's nothing to do with the starter motor.

 

Over the last year I have had 2 out of my bank of 4 'go down' with internal shorts.

[Momac]

I am not convinced there is a problem other than the dud starter battery.

[Alan de Enfield]

1 minute ago, MartynG said:

I am not convinced there is a problem other than the dud starter battery.

Unless the OP comes back I guess we will never know,

[MtB]

14 minutes ago, Alan de Enfield said:

but, explain how  two batteries out of a bank of 4 are flat and the other two aren't.

 

That isn’t quite what the op said though is it? 

 

I thought she she said two were failing to accept a charge when hooked up to a mains charger. And by extension, the other two are. 

 

They were probably all flat. 

 

[Alan de Enfield]

2 minutes ago, Mike the Boilerman said:

 

That isn’t quite what the op said though is it? 

 

I thought she she said two were failing to accept a charge when hooked up to a mains charger. And by extension, the other two are. 

 

I'm not sure - the Ops descriptions and terminology leaves room for misunderstanding.

But we now know the Starter has its own battery and is not connected with the other 4 batteries - 2 of which cannot be charged enough to get a green-light.

Edited November 13, 2018 by Alan de Enfield

[Naughty Cal]

1 hour ago, Alan de Enfield said:

I'm not sure - the Ops descriptions and terminology leaves room for misunderstanding.

But we now know the Starter has its own battery and is not connected with the other 4 batteries - 2 of which cannot be charged enough to get a green-light.

We don't know how long they left them on charge though. If they just put the charger on and didn't leave them long enough?

 

 

[MtB]

The green 'magic eye' charge indicator thing on cheapo leisures is worse than useless in my experience. 

 

The last set of hopelessly sulphated and desperately flat leisures I took to the scrap metal merchant all showed green 'fully charged' in their magic eyes.