Understanding Batteries

Thepipdoc

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Last weekend I bought 2 x Varta 185ah batteries from a local battery supplier - He's not connected to the marine/leisure industry I hasten to add, and I paid £160 each for them.
In keeping with the way I operate I've just researched the most appropriate type of battery to get!

The battery supplier told me the was no such thing as a deep cycle battery and it's a myth, apparently such batteries don't exist. He reckoned that the same batteries that manufacturers label as deep cycle are also labelled as a starting battery and vice versa. Now, I'm pretty clueless as far battery types are concerned and I opted to be guided by the expert i.e. the person that sold me the batteries. I did so on the understanding that if I wasn't happy with their performance I could return them for a full refund - (very fair I hear you say) so I bought them.
I realise it's impossible for me to test the performance of a battery in a month (the period he gave me to return them) and only time will tell how good they are, but I was dammed if I was going to pay £260 that the chandlers wanted for a 185 ah battery, albeit a so called, "deep cycle" battery and anyway, I was going away for the weekend and I knew I would be on a swinging mooring and needed decent batteries. The original batteries would not hold a charge of any kind, and given that I'd fried my genny ( that's another story!) I knew I needed to have reliable power source.

Having done my belated research it would indeed seem that my battery man was indeed correct! Either he was correct, or he wrote the in depth article that appears on this website .
http://www.sterling-power.com/support-faq-2.htm

I feel more comfortable that the batteries I've bought are man enough for the job and they'll stand the test of time.

As a matter of interest he also offered me 2 x 180ah Gel batteries for £250 each, but I declined - it would seem that this type of battery is highly over rated - at least by the author of the article.
 

longjohnsilver

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Phone Exeter Batteries and ask them, they'll invariable be the cheapest and they know what they're talking about.

So how did you fry your Genny? And hope you enjoyed yr night on board.
 

burgundyben

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I understood that a battery with a greater area of lead surface was able to deliver more current over a shorter period (ie engine starting) and that batteries geared for domestic purposes had thicker plates, could deliver less max current but could maintain it over a longer period.

Might be a load of rubbish!
 

Glyn-2008

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http://www.sterling-power.com/support-faq-2.htm

What a great article from that chappie at Sterling. When I was in the industry we generally fitted the standard lead acid type with GEL only fitted to the more unstable sailing craft to avoid unwanted spillage. Sadly, as planning liveaboards, it would now seem that we have to source the incredibly expensive Traction type. I also believe that more battery space will gbe required for these low voltage units as each has 4 sides a top and a bottom.
Thanks for bringing this to my notice.
 

PaulGooch

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I understood that a battery with a greater area of lead surface was able to deliver more current over a shorter period (ie engine starting) and that batteries geared for domestic purposes had thicker plates, could deliver less max current but could maintain it over a longer period.

Might be a load of rubbish!

Technically true, but generally a load of rubbish.

The way to get more surface area is to use thinner plates, but these buckle easily if overly discharged. The big surface area is akin to a big pipe from a tank of water, the large bore of the pipe allows the water out quickly, but the tank is soon empty.

Use a pipe (same outside diameter) with a smaller bore and the water comes out slower, but for longer. The pipe is also stronger.

The supplier that told thepipdoc there is no such thing as "deep cycle" is wrong though, there are deep cycle batteries. These are the ones with thick plates but a smaller surface area, that allow the power out slowly, for a longer period of time. The thicker plates allow deeper discharge without buckling the plates, but do have specific charging requirements. These are no good for starting your engine, as the power cannot get out quick enough.

There are myths and outright lies told about batteries, in particular, the total load of bollox about so called "hybrid" batteries. There is no such thing as a "hybrid" battery. There cannot be, the pipe either has a big bore or a small one, it cannot have both.

There is also no such thing as a "marine" battery, they are just leisure batteries.

Leisure batteries are not "deep cycle" or "hybrid", they are starter batteries, end of. They do generally differ now from normal automotive starter batteries, in that the better ones have extra plate support to help prevent plate buckling and counter some of the rigours of leisure/marine use.

Then there are gel or AGM batteries. It could be argued that they are better on a boat as the acid can't be spilled. But in reality, you're better of with a plain old lead acid battery, as this doesn't need any special charging considerations (such as the ones for deep cycle or gel).

In short, a set of good quality leisure batteries will do very nicely for starting the engines and for running the domestic stuff.
 

TrueBlue

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Last weekend I bought 2 x Varta 185ah batteries from a local battery supplier - He's not connected to the marine/leisure industry I hasten to add, and I paid £160 each for them.
In keeping with the way I operate I've just researched the most appropriate type of battery to get!

The battery supplier told me the was no such thing as a deep cycle battery and it's a myth, apparently such batteries don't exist.
Having done my belated research it would indeed seem that my battery man was indeed correct! Either he was correct, or he wrote the in depth article that appears on this website .
http://www.sterling-power.com/support-faq-2.htm

I feel more comfortable that the batteries I've bought are man enough for the job and they'll stand the test of time.

As a matter of interest he also offered me 2 x 180ah Gel batteries for £250 each, but I declined - it would seem that this type of battery is highly over rated - at least by the author of the article.

He's not quite correct Deep cycle leisure batteries don't exist. But traction batteries do. They've got big chunky plates which take more kindly to repeated charge and discharge cycles. The problem is that they are very expensive. There is a compromise and that is a semi - traction battery

Have a look at this YouTube presentation from CS . He does tend to overstate things on occasion, that comes from years of dealing with boaters (mainly). Look towards the end of the video where he goes int a bit more detail amakes an even handed point

If the batteries you bought are leisure batteries then check that they are at the right price as such.They look somewhat over priced to me. Perhaps compare them with the equivalent Trojan battery might be a more sensible comparison. If you really want to cane them, then perhaps you ought to scale up to semi traction.

Your call
 
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