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Post by Telemachus on Nov 1, 2016 17:48:09 GMT
Well how long did the generic crap last ? How long do you expect the Varta or Hankook to last? I fitted new batteries about this time last year, so I suppose they have done about 250 cycles. However, I recently read this article www.caravanclub.co.uk/media/13871919/ccmnovtechnical.pdf?type=archive which clearly shows that most batteries sold as leisure batteries are not constructed as leisure batteries at all, but are re-labelled starter batteries. In fact, Varta was one of only two brands tested which was a true leisure battery, and Varta are the preferred choice of battery in the road transport industry. Hankook too is regarded as a reliable manufacturer (they supply Toyota and Lexus with batteries). As for whether they would last any longer, I don't know. This is why I dispensed with "leisure batteries" 3 years ago. They're rubbish!
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Post by Mr Stabby on Nov 1, 2016 17:59:20 GMT
Do you have any idea as to the DoD that you discharge your batteries to each time before charging Unfortunately no, I have an analogue and digital voltmeter but nothing to indicate the state of the batteries as a percentage of capacity. I just judge their condition by how long I can run the electrical equipment on the boat before the inverter's low voltage alarm kicks in.
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Post by Deleted on Nov 1, 2016 18:05:16 GMT
I fitted new batteries about this time last year, so I suppose they have done about 250 cycles. However, I recently read this article www.caravanclub.co.uk/media/13871919/ccmnovtechnical.pdf?type=archive which clearly shows that most batteries sold as leisure batteries are not constructed as leisure batteries at all, but are re-labelled starter batteries. In fact, Varta was one of only two brands tested which was a true leisure battery, and Varta are the preferred choice of battery in the road transport industry. Hankook too is regarded as a reliable manufacturer (they supply Toyota and Lexus with batteries). As for whether they would last any longer, I don't know. This is why I dispensed with "leisure batteries" 3 years ago. They're rubbish! I'm beginning to come to that conclusion too. I've got 2 newish 6v Trojans in series at the moment. They seem to struggle with coping with more than 50w a few hours after being fully charged. Might try 2 x 12v car batteries in parallel next time. Probably cheaper too.
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Post by Telemachus on Nov 1, 2016 18:10:53 GMT
This is why I dispensed with "leisure batteries" 3 years ago. They're rubbish! I'm beginning to come to that conclusion too. I've got 2 newish 6v Trojans in series at the moment. They seem to struggle with coping with more than 50w a few hours after being fully charged. Might try 2 x 12v car batteries in parallel next time. Probably cheaper too. Hmmm well what I meant was I've switched to Trojans and they're so much better. How many cycles have yours done? I did find mine surprisingly poor for the first 20 cycles or so and only got to full capacity after 50. But if you are not fully charging them, perhaps they are sulphating? We have 4 T105s and they happily run the 2kw electric kettle (190A or so), the toaster and Nespresso machine (not all at the same time!) in the morning after a night of watching telly and boat lit up with LED lighting strips. They're just coming up to 3 years old.
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Post by naughtyfox on Nov 1, 2016 18:12:10 GMT
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Post by Graham on Nov 1, 2016 18:22:34 GMT
This is why I dispensed with "leisure batteries" 3 years ago. They're rubbish! I'm beginning to come to that conclusion too. I've got 2 newish 6v Trojans in series at the moment. They seem to struggle with coping with more than 50w a few hours after being fully charged. Might try 2 x 12v car batteries in parallel next time. Probably cheaper too. There maybe your problem, you are discharging them too far. How many days do they do? Have you any idea what the off load voltage is when the inverter screams?
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Post by Deleted on Nov 1, 2016 18:54:02 GMT
I'm beginning to come to that conclusion too. I've got 2 newish 6v Trojans in series at the moment. They seem to struggle with coping with more than 50w a few hours after being fully charged. Might try 2 x 12v car batteries in parallel next time. Probably cheaper too. Hmmm well what I meant was I've switched to Trojans and they're so much better. How many cycles have yours done? I did find mine surprisingly poor for the first 20 cycles or so and only got to full capacity after 50. But if you are not fully charging them, perhaps they are sulphating? We have 4 T105s and they happily run the 2kw electric kettle (190A or so), the toaster and Nespresso machine (not all at the same time!) in the morning after a night of watching telly and boat lit up with LED lighting strips. They're just coming up to 3 years old. www.batterystuff.com/batteries/golf-cart-products/6-volt-deep-cycle/t-105-6-volt-trojan-golf-cart-batteries.html2 of these. I thought they are sold as leisure batteries.
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Post by tonyqj on Nov 1, 2016 19:00:13 GMT
This is why I dispensed with "leisure batteries" 3 years ago. They're rubbish! I'm beginning to come to that conclusion too. I've got 2 newish 6v Trojans in series at the moment. They seem to struggle with coping with more than 50w a few hours after being fully charged. Might try 2 x 12v car batteries in parallel next time. Probably cheaper too. Just because no-one else has asked (and because it's important) how are you determining 'fully charged'?
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Post by Telemachus on Nov 1, 2016 19:09:58 GMT
Hmmm well what I meant was I've switched to Trojans and they're so much better. How many cycles have yours done? I did find mine surprisingly poor for the first 20 cycles or so and only got to full capacity after 50. But if you are not fully charging them, perhaps they are sulphating? We have 4 T105s and they happily run the 2kw electric kettle (190A or so), the toaster and Nespresso machine (not all at the same time!) in the morning after a night of watching telly and boat lit up with LED lighting strips. They're just coming up to 3 years old. www.batterystuff.com/batteries/golf-cart-products/6-volt-deep-cycle/t-105-6-volt-trojan-golf-cart-batteries.html2 of these. I thought they are sold as leisure batteries. Yes they are leisure batteries in a sense, however they are normally called "semi-traction" batteries. "Leisure" batteries are normally taken to be dual purpose ones that are often nothing more than re-labelled lorry starter batteries. The clue is whether a CCA figure is quoted, if so they are probably starter batteries.
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Post by Deleted on Nov 1, 2016 20:11:07 GMT
I'm beginning to come to that conclusion too. I've got 2 newish 6v Trojans in series at the moment. They seem to struggle with coping with more than 50w a few hours after being fully charged. Might try 2 x 12v car batteries in parallel next time. Probably cheaper too. Just because no-one else has asked (and because it's important) how are you determining 'fully charged'? 12.8 volts, 12 hours after letting them settle after a charge seems about as close as you can get to 'fully charged'. You will never get 100%!
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Post by tonyqj on Nov 1, 2016 20:22:22 GMT
Just because no-one else has asked (and because it's important) how are you determining 'fully charged'? 12.8 volts, 12 hours after letting them settle after a charge seems about as close as you can get to 'fully charged'. You will never get 100%! Nope, you'll never get to 100%, I was wondering if you were monitoring tail current.
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Post by Graham on Nov 1, 2016 20:34:40 GMT
12.8 volts, 12 hours after letting them settle after a charge seems about as close as you can get to 'fully charged'. You will never get 100%! Nope, you'll never get to 100%, I was wondering if you were monitoring tail current. What is 100% defined as?
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Post by Deleted on Nov 1, 2016 20:42:50 GMT
Nope, you'll never get to 100%, I was wondering if you were monitoring tail current. What is 100% defined as? No further capacity to take a charge given current conditions. The actual capacity is dependent on all sorts of stuff. Temperature, electrolyte, age, number of cycles, charging rate.... sorry, in pub with mate so may have to come back to this.
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Post by IainS on Nov 1, 2016 20:47:23 GMT
If the voltage is (nearly) constant, then AmpHours can be used to measure of energy (V x (I x T)), But that is the problem, V isn't constant. It varies from perhaps 13v shortly after charge, to <11v under heavy discharge. Anyway the battery is fundamentally (due to the way the chemistry works) a charge store not an energy store. I agree up to a point. (TBH, I think we're only discussing semantics!), but what most people are interested in is how much energy they get out of a battery, and how much they need to put back in.
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Post by tonyqj on Nov 1, 2016 20:52:09 GMT
No further capacity to take a charge given current conditions. The actual capacity is dependent on all sorts of stuff. Temperature, electrolyte, age, number of cycles, charging rate.... sorry, in pub with mate so may have to come back to this. Yup. But you can always squeeze just a bit more in if you try for long enough. Nick has the posh word for that: asymptotically.
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