That old chestnut

[Detling]

I am thinking of replacing my battery bank this year, looking around I see that you can get batteries of similar footprint and AmpHours which vary between 24Kg and 40Kg, Should one assume that more lead is better. Note these are not identical batteries but both will fit in the same box and the heavier one is 8% more amp hours. Other specs ie number of cycles warranty length seem the same. If it is not the case that more lead is better then why the massive difference.

 

[zenataomm]

I think the old chestnut about old chestnuts ridding your boat of spiders is just that ...... errrr .... an old chestnut!

[mrsmelly]

I am thinking of replacing my battery bank this year, looking around I see that you can get batteries of similar footprint and AmpHours which vary between 24Kg and 40Kg, Should one assume that more lead is better. Note these are not identical batteries but both will fit in the same box and the heavier one is 8% more amp hours. Other specs ie number of cycles warranty length seem the same. If it is not the case that more lead is better then why the massive difference.

 

 

On another thread I mentioned the six batteries on my last boat each that weighed 54 kilos. They had lead plates 8 mm thick. They had been seriously abused and were not worth messing about with. However much you pay you need to look after them as best you can or the extra money is simply thrown away.

[MtB]

I am thinking of replacing my battery bank this year, looking around I see that you can get batteries of similar footprint and AmpHours which vary between 24Kg and 40Kg, Should one assume that more lead is better. Note these are not identical batteries but both will fit in the same box and the heavier one is 8% more amp hours. Other specs ie number of cycles warranty length seem the same. If it is not the case that more lead is better then why the massive difference.

 

 

 

It depends a lot on what that word "better" means to you.

 

In broad terms a battery with more lead can tolerate more abuse and performance restored with the right charging regime. But a 'better' battery needs its owner to have a clear grasp of how to look after it and the motivation (and time and equipment) so to do.

[WotEver]

Yes, the extra weight is probably more lead which in theory means better life.

 

As long as you look after them properly as Mrs Melly points out

 

And so does the boiler man

[MtB]

 

On another thread I mentioned the six batteries on my last boat each that weighed 54 kilos. They had lead plates 8 mm thick. They had been seriously abused and were not worth messing about with. However much you pay you need to look after them as best you can or the extra money is simply thrown away.

 

I'm curious about this. Full tractions I'd have thought were the most durable and most capable of being brought back from the dead. What was it about them that lead you to believe they were technically beyond recovery?

 

I can understand your reluctance to do it yourself but I have the feeling they could have been saved and recovered by someone with the time, the equipment and the inclination.

[mrsmelly]

 

I'm curious about this. Full tractions I'd have thought were the most durable and most capable of being brought back from the dead. What was it about them that lead you to believe they were technically beyond recovery?

 

I can understand your reluctance to do it yourself but I have the feeling they could have been saved and recovered by someone with the time, the equipment and the inclination.

 

You may well be right Mike. I was then as now liveaboard with no hook up. I would have had to take them to a land base which was not the problem as I had somewhere to take them but the physical size and weight to lug them around to me was prohibitive, each one weighed more than two coal bags and six of them was no joke. Just getting them off the boat was a pain. They were at least 5 years old and had been seriously abused so quick decision for me was to bin em and go the easily obtainable 12 volt 110 jobbies that I was used to it was not a decision made by economics just ease. The gipsy I gave them to must have been well happy when he weighed em in!! I did put them on ebay for a 3 day auction with no takers before I gave them away.

Edited February 7, 2017 by mrsmelly

[MtB]

Yes, the extra weight is probably more lead which in theory means better life.

 

As long as you look after them properly as Mrs Melly points out

 

And so does the boiler man

 

 

Yes. The performance of a 'better' battery will degrade just as quickly as a cheapo battery if the owner only charges it to 80% or 90% and never runs an equalisation cycle.

 

This is the case with (I'd estimate) 80% of boat owners so unless the OP is clued up on how to charge batteries properly, in a year they'll be telling all their mates its a waste of money buying 'better' batteries as they last no longer than cheapies.

 

One partial exception to this is AGM batteries. They seem to tolerate abuse better and degrade more slowly to final death than open lead acid batts.

 

You may well be right Mike. I was then as now liveaboard with no hook up. I would have had to take them to a land base which was not the problem as I had somewhere to take them but the physical size and weight to lug them around to me was prohibitive, each one weighed more than two coal bags and six of them was no joke. Just getting them off the boat was a pain. They were at least 5 years old and had been seriously abused so quick decision for me was to bin em and go the easily obtainable 12 volt 110 jobbies that I was used to it was not a decision made by economics just ease. The gipsy I gave them to must have been well happy when he weighed em in!! I did put them on ebay for a 3 day auction with no takers before I gave them away.

 

 

Yes I totally understand your decision to take the line of least resistance, recovering them would have been a major task with no guarantee of success.

 

I can't help thinking someone on here might not have been delighted with them though, rather than them being weighed in for scrap. Equally though, I can imagine no-one actually turning up to take them out and away despite a LOT of interest!

[mrsmelly]

 

 

Yes. The performance of a 'better' battery will degrade just as quickly as a cheapo battery if the owner only charges it to 80% or 90% and never runs an equalisation cycle.

 

This is the case with (I'd estimate) 80% of boat owners so unless the OP is clued up on how to charge batteries properly, in a year they'll be telling all their mates its a waste of money buying 'better' batteries as they last no longer than cheapies.

 

One partial exception to this is AGM batteries. They seem to tolerate abuse better and degrade more slowly to final death than open lead acid batts.

 

 

Yes I totally understand your decision to take the line of least resistance, recovering them would have been a major task with no guarantee of success.

 

I can't help thinking someone on here might not have been delighted with them though, rather than them being weighed in for scrap. Equally though, I can imagine no-one actually turning up to take them out and away despite a LOT of interest!

 

You are right. I actualy had a supposed buyer on fleabay who didnt turn up and they were stood at the side of my boat for long enough. The shear weight alone coupled with the acid inside them made me decide not to bother with them moving them in my car. God knows how much they are to buy new.

[WotEver]

You are right. I actualy had a supposed buyer on fleabay who didnt turn up and they were stood at the side of my boat for long enough.

That's one of the reasons so many Ebay sellers insist on PayPal and expect payment within 24hrs of the auction end. If someone pays and then doesn't collect you'll feel much better than with someone who offers COD and doesn't collect.

[mrsmelly]

Whilst we are at it..........Why are AGM batteries about 40 percent more cost wise than standard sealed wet batteries? Do they actualy survive abuse better than standard open wet jobbies? I know they are built differently internaly but why the large price difference, are they ever worth it?

[MtB]

Whilst we are at it..........Why are AGM batteries about 40 percent more cost wise than standard sealed wet batteries? Do they actualy survive abuse better than standard open wet jobbies? I know they are built differently internaly but why the large price difference, are they ever worth it?

 

 

I think they degrade a bit slower, and once knackered continue to limp along for years on end.

 

I have two as my starter battery. Must have had them ten years now and I bought them second hand as ready for replacement!

[Detling]

thanks for the thoughts so far I have had 4.5 years from my cheapo batteries so not to upset they need replacing. I was just surprised at the difference in weight at 80% more and only 20% extra amp hours so I wondered what benefit the extra lead gave.

[Guest]

Hi folks I am a newbie hope you don't mind me jumping in on this thread. I have four 130 ah AGM leisure batteries which are now ten years old and are just beginning to get tired. As Mike the boiler man and others said you do have to look after them, I learnt this the hard way after trashing a set of wets in 6 months when first on the boat, I live aboard and am never on shoreline. The solar system charges and conditions them well, with use of engine and gennie in the winter keeping them charged. I am really pleased with them and feel they are worth the expense, so hope that helps.

[mrsmelly]

Hi folks I am a newbie hope you don't mind me jumping in on this thread. I have four 130 ah AGM leisure batteries which are now ten years old and are just beginning to get tired. As Mike the boiler man and others said you do have to look after them, I learnt this the hard way after trashing a set of wets in 6 months when first on the boat, I live aboard and am never on shoreline. The solar system charges and conditions them well, with use of engine and gennie in the winter keeping them charged. I am really pleased with them and feel they are worth the expense, so hope that helps.

 

Thanks for posting. Do you think the agm batteries are worth the extra or is it that you learnt your lesson with the other set and have kept these more charged up as it where? I ask as I am firmly in the buy cheap and bin em school but if they are that much better I was thinking of buying agm this time as mine will soon be needing replacement. Your opinion as a liveaboard matters to me as I also live aboard without shore power. Would you deffo buy agm again next time? cheers

[Guest]

I definitely think they are worth it, I will probably have to replace them this year and will buy AGM again no doubt about it. Other boaters I know who live aboard generally seem to change their 'ordinary' batteries every 2 - 3 years. For your info I run pumps, lights, 12v fridge and evening inverter use for tv or stereo. The stereo is seperates on 240v as is the TV and DVD player ( I don't watch TV programmes via aerial). I only do cold washes on the washing machine via the inverter otherwise for hot wash it's direct off generator.

[RAM]

Hello, another newby here. I have been reading these posts with alot of interest and could you please explain the proper procedure for running an equalisation cycle, and also the reason for doing so. I have 4, 110ah AGM batteries and when I visited the boat yesterday my BTM1 was showing a reading of 14.6v. (fully charged). I have a 100W solar panel fitted. We rarely use the boat in winter but may run the engine for a short while about once a month. Thanks.

[matty40s]

My last set of wet cell batteries were second hand when I bought them, and they lasted 6 years with only one going faulty in that time.

I put this down to having solar panels and never letting them go below 50%.

I replaced them the Autumn before last as they were tired. They continue to have a use powering an electric fence round a horse field, charged by a solar panel.

[WotEver]

Hello, another newby here. I have been reading these posts with alot of interest and could you please explain the proper procedure for running an equalisation cycle, and also the reason for doing so. I have 4, 110ah AGM batteries and when I visited the boat yesterday my BTM1 was showing a reading of 14.6v. (fully charged). I have a 100W solar panel fitted. We rarely use the boat in winter but may run the engine for a short while about once a month. Thanks.

AGMs generally cannot be equalised. The manufacturer's specs for your specific model will give chapter and verse on charging voltages.

 

The 14.6V you are reading does not mean fully charged (although they might well be), you cannot tell the charge status of a battery on charge by reading voltage - that is simply the voltage of the charge source. 14.6V sounds somewhat high for AGMs - is that what is recommended?

 

To answer your questions about equalisation, here's a short description. It is relevant to Wet Lead Acid batteries only.

 

A 12V battery is comprised of 6 supposedly identical cells. Of course, there is no such thing as truly identical, and some cells will deteriorate faster than others. This can be seen by measuring the Specific Gravity (Relative Density) of the cells. When the measurement of the cells begins to noticeably differ, it is time to perform an Equalisation Charge.

 

An Equalisation Charge is nothing more than a timed overcharge - charging the battery for a certain period at a higher-than-usual charging voltage. The battery manufacturer will state the equalisation voltage that should be used for your particular brand, but it is usually in the region of 15V-16V for open wet lead acid batteries. Other battery types will have different (lower) voltages, and some types (specifically Gel batteries) must never be equalised.

 

An Equalisation Charge can also be called a Desulphation Charge because the overcharge voltage will also help in removing sulphation from under-charged batteries, restoring some of their lost capacity.

 

It is important to be aware that an equalisation charge will also damage the battery somewhat, causing increased plate corrosion and shedding.

[Guest]

In reply to Wotever, I have found that the AGMs bulk charge at around 14.6 - 14.7v then cycle through 14.1v and 14.6v when they reach float. Adverc use a state of charge table of 12.8v = 100% 12.6v= 80% 12.4v = 60% and so on to 0% at 11.6v, which I have found a useful guide.

 

I think it is worth mentioning that when thinking about what batteries you want is what demands you are going to put on them, liveaboard, weekend cruising, shoreline access and what charging system/s you have on board. I use 260 watts of solar panels through a Stecca controller set to gel, Adverc controller on the alternator and Victron Multicharger inverter, so there is quite a lot going on there! The AGMs are a sort of in between of wets and gels, being able to take some punishment but not needing charging for as long as gels. They suit my set up but every boat and usage is so different.

[WotEver]

In reply to Wotever, I have found that the AGMs bulk charge at around 14.6 - 14.7v then cycle through 14.1v and 14.6v when they reach float.

The batteries do not set the charge voltage. That is set by the charge source(s). As long as the voltages are set according to the battery manufacturer's specs all will be fine.

[Naughty Cal]

 

Thanks for posting. Do you think the agm batteries are worth the extra or is it that you learnt your lesson with the other set and have kept these more charged up as it where? I ask as I am firmly in the buy cheap and bin em school but if they are that much better I was thinking of buying agm this time as mine will soon be needing replacement. Your opinion as a liveaboard matters to me as I also live aboard without shore power. Would you deffo buy agm again next time? cheers

We currently have a pair of 5 year old Varta AGM's which we are replacing when the boat goes back in the water shortly.

 

They are not completely knackered but are not giving the performance we want anymore so it is time to replace them.

 

Previously we would get through a set of typical wet cell batteries in 2-3 years. So they have lasted longer.

[Tony Brooks]

Wotever is correct is pointing the questioner to the battery manufacturer's data. Somewhere in the dim and distant past Gibbo explained that there seemed to be two types of AGM batteries with different acid components. They each had different maximum charging voltages, one similar to gels and the other like open cells.

 

I get the impression that modern AGMs probably use lead-calcium plates so tend to accept the higher charging voltage. However I very much doubt any sealed battery would take kindly to much equalisation.

[RAM]

AGMs generally cannot be equalised. The manufacturer's specs for your specific model will give chapter and verse on charging voltages.

 

The 14.6V you are reading does not mean fully charged (although they might well be), you cannot tell the charge status of a battery on charge by reading voltage - that is simply the voltage of the charge source. 14.6V sounds somewhat high for AGMs - is that what is recommended?

 

To answer your questions about equalisation, here's a short description. It is relevant to Wet Lead Acid batteries only.

 

A 12V battery is comprised of 6 supposedly identical cells. Of course, there is no such thing as truly identical, and some cells will deteriorate faster than others. This can be seen by measuring the Specific Gravity (Relative Density) of the cells. When the measurement of the cells begins to noticeably differ, it is time to perform an Equalisation Charge.

 

An Equalisation Charge is nothing more than a timed overcharge - charging the battery for a certain period at a higher-than-usual charging voltage. The battery manufacturer will state the equalisation voltage that should be used for your particular brand, but it is usually in the region of 15V-16V for open wet lead acid batteries. Other battery types will have different (lower) voltages, and some types (specifically Gel batteries) must never be equalised.

 

An Equalisation Charge can also be called a Desulphation Charge because the overcharge voltage will also help in removing sulphation from under-charged batteries, restoring some of their lost capacity.

 

It is important to be aware that an equalisation charge will also damage the battery somewhat, causing increased plate corrosion and shedding.

Hi, thanks for all that info. As you say, I will have to look at the manufacturers spec. So with a sealed battery is it correct to check the true voltage using a voltmeter across the terminals. Thanks.

[WotEver]

Hi, thanks for all that info. As you say, I will have to look at the manufacturers spec. So with a sealed battery is it correct to check the true voltage using a voltmeter across the terminals. Thanks.

With any battery you measure the voltage across the terminals BUT you must ensure that there are no loads connected AND you must have removed any surface charge. A simple way of removing surface charge would be to wait for 24 hours for the charge to settle throughout the plates. A more practical method would be to turn on the tunnel light for 10 minutes or so.