Leisure Battery Question.

[oldgit]

Apart from the Vacuflush bog bellows crapping out on our trip up the Thames had to buy a couple of new Leisure Batteries at a local chandlery as the old ones were not holding a charge despite running the engines and regular and annoying espisodes with our generator.
The batteries were of course almost impossible to get at and out.
On return home a rather sophisticated (and borrowed) battery tester gave one of the batteries a reasonably good bill of health but the other gave a readout of
"Unstable battery."
Interweb searches fail to give any real answer to exactly what this means but and assuming it means the battery is about to join my expanding collection of knackered old batteries about to go round to the scrap yard.
A borrowed Porta Pottie reveals a long forgotton aspect of the world of boating.

 

[Refueler]

Its not unusual for a bad battery if it is in parallel with a good battery to look as if both are shagged out. Once the bad one drags the other down - you need charge them separately ...

 

[oldgit]

Have no idea how old the original batteries are/were (Good quality Vetus) .
We have had the boat for 3 years and no trace in the supplied paperwork history of batteries being replaced previously .

 

[jac]

That battery may be ok but the real question is hat would you do with it. Due to it's uncertain age and charging regime it may be about to expire like it's partner did so no real use on it's own unless you are ok with battery failing.
(I would assume that it's 5 years old plus - most sellers would state new battery on the advert when selling so would assume it was 1 year plus when they sold.)

Given it's age of 4+, even if you get an identical model and put it in parallel with it, it will have very different characteristics to the new battery sop is not really suitable to be used in a bank with a new one and damage may occur.

I would discard - it's done a few years service and not worth the risk of keeping

 

[Refueler]

I have old batterys as bench power sources ... they may not be reliable enough for on-board / car use .... but for less demanding use - fine. You'd be amazed at how long a battery can provide such bench service ...

 

[lustyd]

Me too. I don't even charge the bench one as I generally only use it to test new kit at home before taking to the boat so it's been going for a really long time with enough for such uses. That said, now I've gone lithium on board the supply of old knackered batteries will disappear so I guess maybe I should start charging it and looking after it a bit

 

[chris-s]

… or donate to fellow boater. Whenever I leave bits that I no longer need it doesn’t hang around for long.

 

[Refueler]

… or donate to fellow boater. Whenever I leave bits that I no longer need it doesn’t hang around for long.

Many a 'knackered battery' has provided years of service to another !!

I can remember over here - post soviet time .... that it was still normal to put unwanted items by side of road and next day - they'd be gone .. someone had use for them !! But there was an old joke that 'put the wife out there' and she'd still be later !!

 

[trapper guy]

Many a 'knackered battery' has provided years of service to another !!

I can remember over here - post soviet time .... that it was still normal to put unwanted items by side of road and next day - they'd be gone .. someone had use for them !! But there was an old joke that 'put the wife out there' and she'd still be later !!

somebody is bound to be knocking your door the next day asking for a refund!

 

[trapper guy]

Apart from the Vacuflush bog bellows crapping out on our trip up the Thames had to buy a couple of new Leisure Batteries at a local chandlery as the old ones were not holding a charge despite running the engines and regular and annoying espisodes with our generator.
The batteries were of course almost impossible to get at and out.
On return home a rather sophisticated (and borrowed) battery tester gave one of the batteries a reasonably good bill of health but the other gave a readout of
"Unstable battery."
Interweb searches fail to give any real answer to exactly what this means but and assuming it means the battery is about to join my expanding collection of knackered old batteries about to go round to the scrap yard.
A borrowed Porta Pottie reveals a long forgotton aspect of the world of boating.

im in the same situation, have 4x115AH batts on board, two came with the boat, to i brought with me and were only yr old.
after a full charge im lucky if i get an hours use out of all 4, 1 or more of them is clearly draining the life out of the others.
i havent got space to even get near them atm, but as soon as i get to my home port im replacing the two that came with the boat, its just not worth the hassle to do otherwise.
ill charge and test the removed ones, and im absolutely certain at least one of them i hoopa-jooped, if not both.

 

[noelex]

A capacity test is the best way to determine if a house battery is still fit for use. This takes some time, but requires no specialised equipment.

 

[ChromeDome]

The subject has been up before.

A thread
Changing batteries

and a post

To check it properly you should charge it fully, disconnect it and leave it for a couple of hours, then load test it.

The load test can be done with a simple toaster-type checker

If not up to it yourself, hand the battery to a shop - they'll be happy to test it in view of a sale

 

[lustyd]

im in the same situation, have 4x115AH batts on board, two came with the boat, to i brought with me and were only yr old.
after a full charge im lucky if i get an hours use out of all 4, 1 or more of them is clearly draining the life out of the others.
i havent got space to even get near them atm, but as soon as i get to my home port im replacing the two that came with the boat, its just not worth the hassle to do otherwise.
ill charge and test the removed ones, and im absolutely certain at least one of them i hoopa-jooped, if not both.

It's worth highlighting that a single 300Ah LiFePo4 would deliver more usable capacity than 4 115Ah leads and would also last considerably longer before it dies. A Fogstar Drift one is currently £722 which compares very favourably on cost to 4 good AGMs

 

[Tranona]

im in the same situation, have 4x115AH batts on board, two came with the boat, to i brought with me and were only yr old.
after a full charge im lucky if i get an hours use out of all 4, 1 or more of them is clearly draining the life out of the others.
i havent got space to even get near them atm, but as soon as i get to my home port im replacing the two that came with the boat, its just not worth the hassle to do otherwise.
ill charge and test the removed ones, and im absolutely certain at least one of them i hoopa-jooped, if not both.

None of this makes sense. How can you drain 460 amps in an hour on a small boat that you single-hand? suspect you don't have a clear grasp of how 12v works on a boat.

 

[lustyd]

None of this makes sense. How can you drain 460 amps in an hour on a small boat that you single-hand? suspect you don't have a clear grasp of how 12v works on a boat.

They didn't say that, they said the bank is dead after an hour because it's failing. Quite common on lead banks, especially if you do any little thing wrong they die quite quickly. There aren't 460Ah when new usable either, more like 230Ah usable and electronics would probably complain about voltage if there was much consistent load.
This is why lithium is so popular

 

[nevis768]

They didn't say that, they said the bank is dead after an hour because it's failing. Quite common on lead banks, especially if you do any little thing wrong they die quite quickly. There aren't 460Ah when new usable either, more like 230Ah usable and electronics would probably complain about voltage if there was much consistent load.
This is why lithium is so popular

I have heard Lithium batteries on mountain bikes have caused some house fires, is the same true of Lithium boat batteries? I'm a bit wary of them after reading one report which resulted in fatalities sadly.

 

[Hacker]

It’s a different lithium technology.

 

[ylop]

They didn't say that, they said the bank is dead after an hour because it's failing. Quite common on lead banks, especially if you do any little thing wrong they die quite quickly. There aren't 460Ah when new usable either, more like 230Ah usable and electronics would probably complain about voltage if there was much consistent load.

Even if its 230Ah depleted in an hour, that energy (nearly 3kWh) has to go somewhere - it should be quite obvious if that all being spent through one very hot battery!

I have heard Lithium batteries on mountain bikes have caused some house fires, is the same true of Lithium boat batteries? I'm a bit wary of them after reading one report which resulted in fatalities sadly.

People use the word Lithium to describe 4 or more different battery technologies. Some are much higher risk than others. In the early stages of lithium adoption in each market probably all of the different technologies have been used at some point - so it would be wrong to say no boat has ever been fitted with the higher risk types. BUT the type most commonly used on a boat are not a huge risk. Most lithium battery fires happen during charging. Again its not possible to say all ebikes are high risk or all boats are low risk as the quality of monitoring or charging varies with each installation. It would also be wrong to imply that traditional lead acid batteries never contribute to fires - they can outgas hydrogen during (over)charging and poor installations can deliver way more current than the wiring can cope with. Whatever battery type you have it makes sense to consider what happens if there is a fire: will it be detected quickly? can you escape the living space? a lithium fire is particularly hard to put out - but all but the most trivial fires on board are likely to get very bad, very quickly. For what its worth ebikes are not inherenty fire hazards either - but if you have one and leave it charging in your hallway and thats your only means of escape then it might not be the best decision; equally leaving one charging in your damp garage that has no smoke detector and has fuel for the outboard, tins of paint etc might be taking more risk than necessary too.

 

[Refueler]

It’s a different lithium technology.

Early e-bikes tried to cash in on the LiPo format ... light weight - high output - high capacity. But they are touchy and will not suffer abuse. Overcharge or subject them to harsh demand and you can cause them to thermal runaway.
The more common and now near universal format is same as your 'tablet / smartphone / notebook PC' .... LiIon .. a less sensitive battery but still needs charge control. They are also mostly hard cased as well.

Boat batterys are based on LiFe format with the Polymer addition ... giving rise to the LiFePo .... LiFe are far more tolerant of abuse and are unlikely to burst into flames. They still require Charge / Discharge controller to optimise their use.

Just to say that there are a wide range of battery formats based on Lithium .... LiIon / LiPo / LiFePo are only the common ones ...

 

[Tranona]

They didn't say that, they said the bank is dead after an hour because it's failing. Quite common on lead banks, especially if you do any little thing wrong they die quite quickly. There aren't 460Ah when new usable either, more like 230Ah usable and electronics would probably complain about voltage if there was much consistent load.
This is why lithium is so popular

I know that, but why not just remove the duff one as the remaining 3 will be more than adequate for the posters modest requirements.

As ylop confirms depleting a whole bank of that size in one hour means a lot of energy is going somewhere. If you read this poster's other contributions he is a beginner with his first boat and has a limited grasp of things boat related. His description of what happens to his batteries does not make sense in the way he explains it.

Not sure why you are bringing in the different properties of lithium compared with lead acid as it has no bearing on this thread which is all about dealing with seemingly duff LA.