tomboy352
regular
Reged: 14/11/2001
Posts: 55
Loc: Humberside
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Three years ago I replaced my second lot of Tudor batteries for Varta wet deepcycle batteries. Each of the Tudors did five years. The Vartas (2 x 180ah) are down in capacity to, I guess less than half .(ManBat of Chesterfield say they are about 60%) I have 150A alternators with an Adverc, 75w solar pannel and 100w Wind genny. Battery monitor by Link. I take my battery maintenance seriously and little has changed in life-style between the Tudor cruising (no longer available) and the Varta cruising. I have to admit that I always had problems trying to get the S.G 's with the Vartas up. The terminal volts would rise and reduce the charging current but the specific gravities got lower and lower. Another yacht in our club has had the same problem with his Vartas. The supplier cannot find any manufacturing fault, which is a shame as the guarantee still has 12 months to run. What did I do wrong? or am I expecting too much from an expensive Battery ?
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S28
regular
Reged: 19/09/2002
Posts: 3922
Loc: South Coast
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Not sure, but were the Solar panels a recent addition?
I've noticed that "fast" charging with the alternators seems to release some lost capacity that trickle charging never seems to find. No idea why this might be the case.
dv.
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freewind
regular
Reged: 26/06/2005
Posts: 572
Loc: N.Yorks
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I don't understand why, if they will not charge to capacity, the supplier says they are ok.
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tomboy352
regular
Reged: 14/11/2001
Posts: 55
Loc: Humberside
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The solar pannel has been on for about 7 years. When I leave the boat, the batteries are always fully charged by the battery charger, then the pannel and wind genny keep nibbling away slowly at that portion of charge you can never seem to replace. Im not talking of overcharging, but topping up. In winter, I might get 20ah plus a week added to the running total of the battery monitor. But it always felt as though the batteries were always needing a forced heavey charge from a source that only auto electricians might have in their workshops. The Tudor cells, I could keep their S.G's up but not the Varta.
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halcyon
regular
Reged: 20/04/2002
Posts: 2706
Loc: Cornwall
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What voltages are you seeing ? and over what time scale ?
Brian
-------------------- Kddpowercentre designers and purveyors of fine charging systems for 30 years.
Powercentre spares and help line
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dk
regular
Reged: 30/05/2001
Posts: 314
Loc: UK, Somerset
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360Ah of deep-cycle batteries would require a 40A, 3-stage mains battery charger to properly get them up to a fully charged state. Most people have trouble because they buy too much capacity, but don't have a serious enough charger. Your 75W solar panel & 100W wind genny will be pretty much useless on a battery bank of this size, unless first taken to 98% capacity by a hefty mains charger or alternator with smart regulator. If you've let them drop below 30% charge they will be useless by now i'm afraid!
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csail
regular
Reged: 24/08/2005
Posts: 3186
Loc: Rhoose/Cardiff Bay,UK
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Same here, i had to buy a full set of new batteries.
-------------------- Marine grade vinyl boat names & graphics made to order just pm me.
Reduced price for you guys seeing as it is only a hobby. http://www.h2o-marine.co.uk/
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tomboy352
regular
Reged: 14/11/2001
Posts: 55
Loc: Humberside
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I have a 2 stage 20A battery charger.When on long cruises, I have never discharged below 100ah and the 150a alts recover this without problem. I noticed the battery capacity problems this winter,(using the boat as an occasional caravan in the marina) With 50ah discharge and a 10A load,(a typical load is nearer 5A) I was showing 11.9v and the heater was failing with low battery code. The charger cuts out after perhaps a couple of hours, we show 13.2v If I leave the boat and return with a little weak sun, I often see about 13.8 on the monitor but this quickly drops off on discharge. The S.G just reach 1220. A few months ago a attached a Halford's car charger for 60 hours, kicking out 1A or so. and managed to lift th S.G to 1250 but this was not a cure. We are about to embark on a 5 month cruise of Ireland where we will spend most of it on anchor. Tryinf to rejuvinate my vartas with some heavey charging might not give me the peace of mind that new batteries would. Culd it be that the marina use of the batteries is not being recharged by my battery charger although I am not deep discharging but recharging at about 50ah discharge ? And that the cruising system I emplay is probably ok?
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wotayottie
regular
Reged: 01/07/2007
Posts: 1856
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Quote:
I don't understand why, if they will not charge to capacity, the supplier says they are ok.
Simple. Batteries are like shoe leather - they wear with use and capacity continually falls. They are not like a piece of electronics which either works or doesnt. And the extent to which battery capacity falls and the time it does it in depends on the way they are used.
Usually a very small number of cycles to full discharge are sufficient to bugger up a battery entirely.
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wotayottie
regular
Reged: 01/07/2007
Posts: 1856
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The obvious question is how far are you typically discharging the batteries?
Two 150 amp alternators sounds like too much for the size of the bank. Cant remember what the rule of thumb is now, but I'm sure it isnt 1 for 1. My 200 AH of batteries works fine with one 60A alternator.
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