Replacing batteries

[Shantih]

I own a Bavaria 46 new in 2005. She has operated as an RYA RTC and charter yacht so regularly in use for around 24 - 30 weeks per annum. She made 5 voyages to the Med and back for winter sailing until 2011. The first set of lead acid batteries (3 x 145 AH) performed well for 4 years and the new set have done the same . . . until recently due to an oversight with shore power charging when they drained completely over a 2 week period. Now on charge but I fear will need to be replaced. I understand it should be possible to benefit from a much longer battery life. So what with is the question please, gel or the same or something else?

[Dockhead]

Most people here will advise you to go with open-cell deeper discharge batts -- like golf cart batts -- IF you are going to spend much time off shore power (boats used for weekends which mostly live in marinas are a different matter). Gels and AGM's have their proponents, but I think they are in the minority.

Deep discharge batteries have thicker plates and can withstand much more use and much more abuse than "leisure" type batteries. People often get 5, 6 even 10 years out of them.

Once incident of leaving them dead for a couple weeks won't kill a good battery, so you might want to have a go at reviving yours. I have a set of Trojans in my boat which have been left dead twice -- once for a month, due to varous stupidities (breaker flipped off on shore power when I was away from the boat, and I had a small load on, for example), and they are still performing as new after two years of service.

You should equalize your batts after they are fully charged, and there are other tricks for reviving dodgy batteries which you can find if you use the search feature on this site. You might still get a couple of seasons out of them.

The key to battery life is never letting them go below about 50% state of charge, topping them off with a really good absorption charge at least once a week, and equalizing regularly. Solar power is really excellent for this because you get an excellent finishing charge, unlike the case with a generator where you don't want to leave the generator running after the battery stops accepting much charge.

Good luck and let us know how you make out.

[Pete7]

30 weeks a year is quite high usage, do you see this continuing or will be the yacht revert to a more pleasure sailing for holidays and weekends.

The reason I ask is the previous owner managed 7 years from FLA batteries and I managed 5 on the last set only failing when the battery switch failed to disconnect. With solar charging I expect 6 - 7 years from the current set.

Batteries are expensive in the UK and posh ones like AGM or gel even more so. There is a balance between cost, life and availability and for us its FLA.

You could have a read of this, its a philosophy I agree with.

Sterling Power Products: What is the best battery to use for an auxiliary charging system?

Pete

[sailinglegend]

Originally Posted by Pete7

...You could have a read of this, its a philosophy I agree with.

Sterling Power Products: What is the best battery to use for an auxiliary charging system?

Pete

As a moderator on this Forum you should know better than to link to this very old and very out of date article by a man that every professional in the UK industry laughs at for these kinds of inaccurate comments.

[Dockhead]

Originally Posted by sailinglegend

As a moderator on this Forum you should know better than to link to this very old and very out of date article by a man that every professional in the UK industry laughs at for these kinds of inaccurate comments.

What exactly is inaccurate?

[djmarchand]

What is inaccurate? Well for one thing his statement that you can't charge AGM batteries any faster than lead acid batteries. Not true. AGMs have an inherent lower internal impedence that permits faster charging without disassociating electrolyte, "boiling".

But having said that, I do agree with his basic premise that traction batteries, which for most of us means golf cart batteries, provide the most bang for the buck.

David

[Cheechako]

Gel are great maintenance wise. Not sure you will see enough further life for the extra $ though. Probably 5 years average, 7 if you're a lucky guy.

[Pete7]

Originally Posted by sailinglegend

As a moderator on this Forum you should know better than to link to this very old and very out of date article by a man that every professional in the UK industry laughs at for these kinds of inaccurate comments.

Moderators on CF are perfectly entitled to express their opinions just as all members of CF are and you are completely wrong to imply anything else. I will take this opportunity to remind you that the CF moderators are unpaid volunteers who give up some of their spare time each week to help keep CF running smoothly. This is time they could be spending with friends or family, working on the boat or sailing.

Personally I happen to agree with Charles Sterling and I suspect lots others do to. You may not like his rather abrupt approach to customer relations, but then as he states he is an engineer not a salesman.

The reason I asked if this yacht is going to be used less in the future is it would then fit in with the recommendations that Charles makes at the end of his article. Remember I did say it was a balance between cost, life and availability. Sure the latest AGM or gel batteries might be very nice to have on board but most of us are on a budget and a new battery bank doesn't come cheap particularly in the UK. If that new AGM bank lasted the same length of time as FLA due to an imperfect charging regime then that is money just wasted.

Just to show I am willing to put my money were my mouth is, this is what I use, you will note the 60% depth of discharge. AGM Lifelines by comparison are £300 in the UK. Will they last 3 times as long? of course not.

813010 Varta Hobby Leisure Battery A28 12V 110Ah 81310 - Leisure Batteries - Varta Professional Leisure Batteries

Now you are welcome to disagree with me, so lets here the arguments for an alternative that fits the OP requirements, but I think you hit the nail on the head with this post earlier today:

Originally Posted by sailinglegend

So a 500Ah AGM bank needs a 120 amp alternator and shorepower charger(5% extra to supply boat loads). If you can't charge them properly don't waste your money.

Peter

[sailorboy1]

Originally Posted by Pete7

Now you are welcome to disagree with me,

Peter

will there be any kissing later if someone "gives"

[ullar]

Originally Posted by sailinglegend

As a moderator on this Forum you should know better than to link to this very old and very out of date article by a man that every professional in the UK industry laughs at for these kinds of inaccurate comments.

Mr. Sterlings sayings are a bit rough but being a physicist I have to say that they make more sense than many professional salesmen speeches.

[sailinglegend]

Originally Posted by Dockhead

What exactly is inaccurate?

You shouldn't really have to ask this question.

I started to copy the points that I consider inaccurate, but the list got too long. Basically the first half is mostly ranting rubbish. There is some good stuff in the middle, but you should see his "Advanced Charging" article where he claims 6000% increase in charging with his chargers - and his "fast charge" ideas are based on his tests where he put 160 amps into a standard 100 Ah wet cell, and he was happy that the temperature went up to 50C. Trojan recommend a charge rate of 10 amps for a 100 Ah battery.

He suggests leisure batteries are just starter batteries, and if an AGM battery can output enough CCA then it is a starter battery. This is just inaccurate and misleading and clearly shows his ignorance. He's effectively saying just buy a cheap starter battery and don't waste money on a deep cycle - unless its an expensive traction battery.

He lumps all sealed batteries together and his main thrust is that you can only charge batteries fast with high voltages - I don't think he has ever seen or tested a proper deep cycle AGM.

His conclusion is also wrong - fast charge rates don't cause gassing - high voltages cause gassing, and both Gel and AGM have very good cycling numbers.

The whole "tone" of his article was to junk ALL sealed batteries because way back around the time of this article his chargers were not proper Adaptive Chargers and caused a lot of problems. Around 2009 he introduced his "Power Pack" function so that the charger would output full charging current in Float Mode and not automatically go back to Absorption voltages when the batteries were already fully charged.

I'm only defending AGMs here. But I do agree with him that sealed leisure batteries should not be used on cruising boats - but I would add only because they can't be equalized like some AGMs. Some Gels are also very good with many years of service if handled with respect.

The bottom line is most people abuse their batteries so open wet lead acid are a very good option.

[Pete7]

Originally Posted by sailorboy1

will there be any kissing later if someone "gives"

Perhaps , my excuse is I haven't had a cigarette for 72 hours. Wife, kids and the dog are tip toeing around me.

Pete
The reformed smoker

[Pete7]

The article should anyone wish to read it and make their own informed opinons of advanced charging by Charles Sterling.

http://www.sterling-power.com/images...edcharging.pdf

Pete

[d design]

Back to the subject, Dont forget to consider LiFePo4

[Dockhead]

Originally Posted by sailinglegend

You shouldn't really have to ask this question.

I started to copy the points that I consider inaccurate, but the list got too long. Basically the first half is mostly ranting rubbish. There is some good stuff in the middle, but you should see his "Advanced Charging" article where he claims 6000% increase in charging with his chargers - and his "fast charge" ideas are based on his tests where he put 160 amps into a standard 100 Ah wet cell, and he was happy that the temperature went up to 50C. Trojan recommend a charge rate of 10 amps for a 100 Ah battery.

He suggests leisure batteries are just starter batteries, and if an AGM battery can output enough CCA then it is a starter battery. This is just inaccurate and misleading and clearly shows his ignorance. He's effectively saying just buy a cheap starter battery and don't waste money on a deep cycle - unless its an expensive traction battery.

He lumps all sealed batteries together and his main thrust is that you can only charge batteries fast with high voltages - I don't think he has ever seen or tested a proper deep cycle AGM.

His conclusion is also wrong - fast charge rates don't cause gassing - high voltages cause gassing, and both Gel and AGM have very good cycling numbers.

The whole "tone" of his article was to junk ALL sealed batteries because way back around the time of this article his chargers were not proper Adaptive Chargers and caused a lot of problems. Around 2009 he introduced his "Power Pack" function so that the charger would output full charging current in Float Mode and not automatically go back to Absorption voltages when the batteries were already fully charged.

I'm only defending AGMs here. But I do agree with him that sealed leisure batteries should not be used on cruising boats - but I would add only because they can't be equalized like some AGMs. Some Gels are also very good with many years of service if handled with respect.

The bottom line is most people abuse their batteries so open wet lead acid are a very good option.

An interesting and well-reasoned response. Thank you.