A definitive guide to 12v batteries and their charging.

H

Heckler

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During the heated debate that has just taken place about battery charging, in which I apologised for my boorish behaviour, I found this website: http://www.batteryuniversity.com/partone-13.htm it seems to give all the relevant information (and it ties up with what I read in Nigel Calders book)
The interesting points from our point of view is the bit where it gives advice on what voltages to look for to give a good idea on the state of charge of your batteries.
Stu
 
Yes thats a good one.

Some others I have noted over the years. Some better than others. Apologies for any that are not much good, are irrelevant and links that dont work.

http://www.mpoweruk.com
http://www.batteryfaq.org
http://www.smartgauge.co.uk/technical1.html
http://www.attfield.dircon.co.uk/page20.html (but unfortunately the Voltwatch gauge is NLA.)
http://www.buchanan1.net/lead_acid.shtml
http://www.adverc.co.uk/technical/

Finally convert your petrol mower to solar charged electrical http://www.arttec.net/Solar_Mower/index.html

Final tip as winter closes in (this weekend I undersatnd) Don't store your battery on a concrete floor. Comments to be written on toilet paper and flushed away!
 
This is not a definitive guide!!

It is 4 years old, doesn't mention GEL, AGM or the words Leisure, Deep Cycle or even Marine.

Nigel Calder is a very good reference source - a bit too technical for some people.

It's good to see that VicS doesn't have a link to that awful Mr Stirling.
 
Final tip as winter closes in (this weekend I undersatnd) Don't store your battery on a concrete floor.

*************************************************
Only Vic could drop this one in as he shut the door and ran!!!!!!!!!!!!!!!!

/forums/images/graemlins/laugh.gif
 
Hmmm, theres me turning over a new leaf, determined to not use boorish behaviour and then this!
Nigels book, I bought about six years ago, so the info I referred to is "older" than the website stuff and yet you praise that.
Mt Sterling has always been v nice to me, talked to him several times, his product worked superbly on my last boat and I have just bought another one.
So why be combatative?
Stu
 
The general urban myth always was dont leave batteries on concrete and I vaguely remember someone coming up with the reasoning but cant remember it, please enlighten us!
Stu
 
[ QUOTE ]
I vaguely remember someone coming up with the reasoning

[/ QUOTE ] Yes I think it might have been me. Something I made up. If it was about temperature gradients causing a smal difference in potential at the top and bottom of the plates that was it.
 
Is it wrong to leave them on a concrete floor ???

I'm on a steep learning curve when it comes to batteries, I enjoyed the info in the last post, doubled my knowledge....

I've now got my batteries sitting on the floor down in my gimp chamber.....ON A CONCRETE FLOOR....oh gawd...what have I done!! /forums/images/graemlins/grin.gif
 
[ QUOTE ]
Mr Sterling has always been v nice to me

[/ QUOTE ]

I'm sure he is a very nice man - what I was referring too was his awful, incorrect and generalised comments. There is an article by him often quoted by the uninformed on this forum where he dismisses GEL and AGM for boats. This is exactly oposite to Nigel Calder's ideas. I believe Nigel Calder.
 
Ah but you see what we found out from the bad tempered exchanges, where I apologised, is that none of us is totally right. Because you think that Mr Sterlings comments are wrong doesnt mean that you are right. Dont forget that there are less experienced members of this forum who listen to advice given and one should be careful when posting!
/forums/images/graemlins/wink.gif
Stu
Anyway Bom Dia, uma cerveja para me, faz favor (sic)
 
Vic
I think it was to do with vibration from gen sets, it would go thru the frame and shake the plates.
Stu
PS found this after
BATTERY MYTH:
"Never leave batteries on the ground or a concrete floor...all the power will leak out."
This one is a "rural legend"--batteries don't care what they sit on. It probably orginated from when batteries came in porous wooden cases. There are some truths behind this myth, though! All batteries do self-discharge over time when they are not being charged. If dust and dirt build up on the battery tops, sulfuric acid will carbonize the grime into an electrical conductor, acting like a short circuit across the terminals and quickly draining the power. Cold temperatures also reduce available power from a battery. And thermal gradiants can reduce the life of large battery...this can occur when the air temperature around a battery is much warmer than the surface it is sitting on.
 
[ QUOTE ]
This is not a definitive guide!!

It is 4 years old, doesn't mention GEL, AGM or the words Leisure, Deep Cycle or even Marine.

Nigel Calder is a very good reference source - a bit too technical for some people.

It's good to see that VicS doesn't have a link to that awful Mr Stirling.

[/ QUOTE ]

Being about to replace and enlarge my whole battery bank, this is all very topical to me.

First - I find Mr Stirling excellent - however whether his advice - which I think a few years back was realistic, I am not so certain now. The only thing that would clinch my business to move to high tech batteries is the rate that they can be charged. If the Gels or whatever can accept charge at double the rate, which means I can charge for half the time - that would be the reason for me going to these batteries. If not - why bover....?

I can't find this info in any form that I can understand. Any one else have anything to add here?
 
[ QUOTE ]
Being about to replace and enlarge my whole battery bank, this is all very topical to me.

First - I find Mr Stirling excellent - however whether his advice - which I think a few years back was realistic, I am not so certain now. The only thing that would clinch my business to move to high tech batteries is the rate that they can be charged. If the Gels or whatever can accept charge at double the rate, which means I can charge for half the time - that would be the reason for me going to these batteries. If not - why bover....?

I can't find this info in any form that I can understand. Any one else have anything to add here?

[/ QUOTE ]Like many others, I'm not convinced at all by a lot of what Mr Sterling writes, although some people continue to portray him as a shining example of ultimate battery knowledge.

The fastest recharge rates are with AGM batteries (because they have the lowest internal resistance). However, they won't recharge twice as fast as ordinary batteries; many manufacturers are cagey about claims in this respect, but where figures are quoted they tend to say about 30% faster than ordinary batteries.

Gel batteries need careful charging to avoid damage. But they are more resistant to deep discharge and, for a given depth of discharge, will last for more discharge cycles than AGM batteries. But, they're very expensive.

As you're about to buy batteries, let's consider the economics. AGMs cost about twice as much as decent sealed maintenance-free batteries. From a recharge point of view, they'll recharge 30% faster. But for the same price you could buy twice as many sealed maintenance-free batteries, which mean that your bank would recharge twice as quickly!

There's another big advantage of having a bigger battery bank. For a given amount of usage, the depth of discharge is much less - and it's the depth of discharge which ultimately shortens the life of batteries.

I've posted many times here that the most cost-effective improvement you can make to a boat's electrical system is to add more batteries. Sure, there's a one-time cost in wiring and building battery boxes, but after that it's all benefit.

I put this theory into practice about 10 years ago, when I replaced my old domestic bank of 2 x 130Ah batteries with a new bank of 6 x 110Ah sealed maintenance-free batteries. They worked brilliantly for 10 years, and I've just replaced them with similar batteries. Why sealed maintenance-free? Because they're clean, never need attention, won't spill, and are quite resistant to overcharge (an important consideration if you have a smart regulator fitted). I chose Merlin Powerpack batteries, which are reasonably priced for their specification.

Hope this helps your decision-making.
 
[ QUOTE ]
If the Gels or whatever can accept charge at double the rate, which means I can charge for half the time - that would be the reason for me going to these batteries. If not - why bover....?

[/ QUOTE ]

The best thing about these forums is when people respond with their actual experiences, and not just with their theories. (I'm not trying to be controversial).

After extensive research we went for Lifeline AGMs from Merlin. They are more expensive than wet cells but they have many advantages. See their excellent web page

Lifeline AGM main advantages are:
User Safe
sealed construction
non-spillable
install in any position if properly supported.
submersible without damage
Maintenance free (no adding water or repairing corroded terminals)
Fastest recharge. (no current limitations with voltage regulated recharging)
Deep Cycle (thick positive plates to provide real deep cycle performance)
Outstanding cranking performance (aircraft cell construction lowers internal resistance)
Best charge retention (especially against flooded cell types)
Lowest discharge rates (Less that 3 percent per month unattended)
Twice as many discharge/charge cycles as the leading gel marine battery.

See this web page for comparisons between flooded, gels and AGMs
[ QUOTE ]
The higher charge efficiency of AGMs allows you to recharge with less energy: Flooded cells convert 15-20% of the electrical energy into heat instead of potential power. Gel-cells lose 10-16% but AGMs as little as 4%. The higher charge efficiency of AGMs can contribute to significant savings when it comes to the use of expensive renewable energy sources (wind generators, solar panels, etc.) as your charging system can be 15% smaller (or just charge faster).[ QUOTE ]

I have never had Gels so cannot compare them to AGMs. With Lifelines we can put in as much charge as we like. Our Fischer Pandas genny charges at 280 amps.

We are living aboard so battery performance is very important. If the emergency services use Lifeline batteries then that was good enough for us. Google AGM GEL COST to see comparisons - and Lifeline come out as cheaper in the longrun.

The other point to remember is that not all Gels or AGMs are the same - you get what you pay for.
 
Peoples experiences, exactly right, Charles Sterlings regulator, does what it says on the box, he did that controversial mag interview a few years ago, lead acid, vented, best thing cause you can raise the charge rate really high BUT you have to watch the acid level cause it evaps the water.
OK he was right, unconventional, forthright, doesnt suffer fools gladly, (or who he thinks are fools!)
Interesting to talk to as well
Stu
 
You're right to say that Lifeline AGMs are excellent batteries, and I'd agree if their cost isn't an important factor. I somehow got the idea though that Chris Robb was looking at making a value judgement on whether to buy more expensive batteries in order to get faster charging.
 
[ QUOTE ]
put this theory into practice about 10 years ago, when I replaced my old domestic bank of 2 x 130Ah batteries with a new bank of 6 x 110Ah sealed maintenance-free batteries. They worked brilliantly for 10 years, and I've just replaced them with similar batteries. Why sealed maintenance-free? Because they're clean, never need attention, won't spill, and are quite resistant to overcharge (an important consideration if you have a smart regulator fitted). I chose Merlin Powerpack batteries, which are reasonably priced for their specification.


[/ QUOTE ]

All interesting stuff - yes - I am doubling the battery bankd size from 1 x 200 ah battery to 4 110 ah, much on the basis that more batteries is less discharge. I will look to see if I have space for more - but I think will be difficult to accommodate.

Thanks for your comments
 
[ QUOTE ]
I will look to see if I have space for more - but I think will be difficult to accommodate.

[/ QUOTE ]I put my 4 extra batteries in a plywood box built under the double bunk in the aft cabin, and wired them in parallel with the 2 in the original battery box. As an aside, with multiple batteries in one bank, it's wise to connect the boat's main negative and positive cables to opposite ends of the bank.
 
Mr. Sterling ....... don't get me wrong - I am not arguing whether he knows his stuff or not. He obviously knows something as he's still in business.

What I am always wary of is advice / information from a source that has one interest - own interest to sell own products.

It's a good reason why I do not ask a well known "Marine Electrical Supplier" about marine wiring and packs / batterys etc. They will advise buy their gear. Friend of mine did - spent a lot of money in fact and still has same problems as it all was supposed to cure.

IMHO charging problems and necessary cures are created by people "upping the anti" and adding fancy gizmos, taking the subject out of it's simple wire here, wire there foundation.
 
How are you getting on with the AGMs and the deep discharge technique? If I remember correctly, you have a dc genny, huge inverters and a large AGM bank?

Re Sterling. It seems that all his recent products are made in the Far East and badged. From all accounts some of them are good products. I like the sound of the dc-dc converter as an alternator controller. Can give genuine four-stage controlled charging regardless of the output of the alternator regulator, which the basic Adverc and Sterling cannot do, of course, because they cannot step-down.

From what I have seen of the products the real weakness is not being waterproof. If you look at the Balmar range you could point a fire hose at them and they would be fine. That's how electrical kit for use in the engine compartment should be.
 
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