New batteries

rivonia said:
This was an excellent report and has I believe helped a lot of fellow sailors......
Which battery (deep Cycle/Traction) would be best for a permanant live aboard.
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The problem with the report is that his conclusion about AGMs is totally wrong. Gels I agree should not be used - they are old technology (1957) but AGMs are far better in every respect.

My Lifelines have a high CCA rating, they have thicker plates than a Trojan L16, and their best feature is they charge at any rate you can throw at them, which means they charge so much faster than anything else - which saves fuel, maintenance and engine or genset life. My DC genset puts 280 amps into my bank. AGMs self discharge only 1% per month compared with 10% for tractions and they can't freeze, so great if your boat spends a lot of time on a swinging mooring in the winter.

Ours have lasted 7 years of permanent liveaboard usage - 4 years in the heat of the Med - so that has to be a good recommendation.
 
WHY knock Sterling? It is HIS oppinion and he is entitked to it. I found his report interesting.
It may not be agreeable to everyone else, but why have a go at him.

I use sterling inverter and battery management system. Both very reliable.

Fair winds

Peter
 
rivonia said:
WHY knock Sterling? It is HIS oppinion and he is entitked to it. I found his report interesting.
Click to expand...

A fair question which clearly deserves a longer reply.

Mr Sterling has got his facts wrong - or he is lying to promote his products which are not "sealed battery” friendly. He is a law unto himself – which is fine if you will then stand up and defend your ideas in public – but he will not respond to emails when his ideas are criticised.

Let me quote from Charles Sterling's original article:

“So the question is; if these batteries are 3 – 5 times more expensive than the standard one, what do they do that is 3 – 5 times better? Do they last 3 – 5 times longer? (I think not, more like the reverse). Do they charge 3 – 5 times faster to reduce your engine running hours? (Only in their dreams.) So rather than ask me weird questions; please ask the sales man, who is trying to sell this stuff for cycling, exactly what you are getting that is 3 – 5 times better than standard lead acid batteries. Then please let me know as I could do with a good laugh."

With the number of postings now on these forums I think the laugh is now on him as he has failed to see the main advantage of batteries such as AGMs.

Forget the advantages of AGMs that they can be placed upside down, or you don't need to top them up with distilled water, or they have only a 1% self discharge per month compared with open lead acid, or they won’t freeze - let’s just concentrate on the one main feature that does make them 3 times better - they do charge much faster than other batteries, and by the way mine have lasted for 7 years – as a full time liveaboard.

Mr Sterling assumes that they can't charge faster because they can't accept a high charging voltage. As an engineer he has totally ignored the point that batteries charge acceptance is not only a function of the charging voltage but also a function of their internal resistance. So to recharge a normal wet lead battery - open or sealed - by say 100 Ah you would need to put in about 120Ah, to recharge an AGM you would only need to put in 102 Ah that’s nearly 20% less, which means 20% faster charging – no matter what charging voltage you apply.

If you now add in the other advantage of AGMs that because of their internal resistance they can accept a much higher charging current without overheating you can see how the claims that AGMs charge faster start to add up.

According to most manufacturers a wet lead acid battery should be charged at about the Ah capacity divided by 4, or C/4 to guarantee a safe charge. So for a 100 Ah battery that’s 25 amps. Some manufacturers like Trojan recommend C/10 for safer charging. Lifeline AGMs for example say you can charge at CX5 that’s 500 amps. Lifeline's figures are totally impractical but it does mean that you can up the size of your shorepower or alternator as high as you can afford and you will pump more amps in more quickly. As charge levels rise all batteries will limit the current acceptance to about C/4 – otherwise you AGMs would appear to fully charge in a ridiculously short time!

Mr Sterling claims he offers “fast charge” but to do this he takes the voltage up to 14.8 volts. Battery performance is temperature dependent so at 25c they gas at 14.34v, but at 40c they gas at 13.98v. Using his chargers sealed batteries will lose water which cannot be replaced and will shorten their life.

Another quote from his article which confirms his lack of understanding of AGMs is here:

“Fast charging costs water, i.e. if you want to charge you batteries fast, don't touch a Sealed/Gel/AGM etc with a barge pole. Fast charging will result in a certain % water loss from the battery. If the battery is sealed the water loss cannot be replaced. REMEMBER FAST CHARGING AND SEALED/MAINTAINCE-FREE ARE A CONTRADICTION OF TERMS. You may not like this, but tough, it's the way it is.”

These comments should make you realise that Sterling chargers should not be used if you have “sealed batteries”.

One final thought to be aware of there are different brands of AGMs, not all deep cycle, so maybe he has been playing with the wrong ones, like some posters on these forums who have had problems with AGMs.

For another good link which will take you to several articles and lots of comments from other users go to a cruisers site that has for the last 18 months been testing Lifeline AGMs to see if they live up to their claims:

http://www.morganscloud.com/2012/01/29/battery-test-18-month-report/
 
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Have you read Morgans Clouds' stuff? Not sure their regime is even close to practicable for the typical leisure boater. Also not sure whether the same regime wouldn't have the same positive effect on wet batteries.... In which case, save your money?

They haven't carried out the same test on any other type of battery, so not really a comparison, merely a test.

This isn't a criticism of Morgans Cloud - They dont suggest that the test/report is a comparison with previous types, They got their AGMs for free, and I think they tend to suggest that, whatever batteries you have, following a regime like theirs will lead to a longer life.

As long term liveaboards Morgans Cloud provide masses of info on a variety of equipment they have used, and it's incredibly useful and interesting. Their comments on anchors were enough to convince me to go in search of a new generation anchor.... They have a Spade as their main anchor, and they suggest that a Rocna or Manson Supreme could be equally effective.

I still can't see why AGMs are worth a multiple of the price of cheap wet batteries - but I'll be looking a bit closer :) it would be interesting to see the sources which support their faster charging etc..
 
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>Thanks for the reply.....3 x 12vs it is!

Couple of thoughts on that. As said the best house batteries are deep cycle/traction batteries with Trojan leading the way. I'd check which option best fits the battery box six six volt Trojans or three 12 volt Trojans, obviously there is no differnce in output.
 
The alternative religion to anchors - batteries

After 10 years of use, I'm getting bored with my wet leisure batteries, but they just haven't died yet. Maybe the secret is having too many of them, so they rarely get stressed out.
Two arguments not yet made are accessibility and form factor. If you can't easily get at the batteries, then AGM makes life easier. If you can get more capacity in the available space by banking up specific battery shapes, then that is likely to last longer. Plus wet lead acid really needs venting and protecting from spills. AGMs shouldn't need that.
I dream of the motor industry driving down the cost of Lithium ion. Amen.
 
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