Guest Tracker Posted February 12, 2010 Share Posted February 12, 2010 After a short spell with the transformer bunging in 16.V - but at unknown amps - I then left them on a 'maintainance' charge for 36 hours then let them stand off carge and disconnected from everything overnight. At the time the charging stopped both were reading 13.03V and after 12 hours standing they showed 12.95 and 12.97V. They have now been standing linked in parallel for two hours and the voltages remains at 12.95. This, to me anyway, suggests that both batteries are good and that there is no inter reaction or compatibility between the different types? Will now do a discharge test and also see what current leakage there is when the batteries are in situ on the van and everything is allegedly turned off. I could consider a battery isolating switch for use when the van is not in use I suppose to conserve power. I know that many amongst us suffer with battery issues and I hope that the info from this thread will help others to understand what goes on in the battery department as it has me and I thank everyone for their ongoing contributions. Link to comment Share on other sites More sharing options...
spospe Posted February 12, 2010 Share Posted February 12, 2010 Tracker The voltage readings of your batteries give some cause for optimism. It’s normal for a fully charged ('fizzing') battery to quickly drop from the 14.xx volts to around 12.xx when the supply voltage is removed. What matters now is the test load and how long it can be maintained to the 70% discharged point. Something to bear in mind is that a failing battery will often show a good terminal voltage and will often seem to charge-up quickly. In practice, such a battery has lost most of its capacity and so when recharged seems to reach a state of full charge in a short time. You can only really determine its actual capacity by a test discharge. Have you checked the electrolyte levels? If the plates are not covered, then a) the exposed part will be prone to crumbling and b) the actual capacity of the battery will be reduced. Low maintenance dos not equal no maintenance. Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 12, 2010 Share Posted February 12, 2010 Good points Michael, thanks. The Elecsol electrolyte level is fine but the Moura is sealed and I can't get it off with sensible force although nothing ever seems to have exuded from the overflow tube as there are no stains in or around where it vents. Maybe my digital multimeter ist kaput! Test discharge time methinks! Link to comment Share on other sites More sharing options...
Brambles Posted February 12, 2010 Share Posted February 12, 2010 Have a suggestion for you tracker. You mentioned you has lots of bulbs. Put yoru two batteries in series so 24 volts. Put your lamps in sets of two in series, and use them to load the batteries. This way you are loading both batteries identically and both will supply exactly the same power (current). Then during and after the test you will have a direct comparison between the batteries from the voltages measured across each battery and see how balanced they are. Also cuts the time to do the test. Removing the battery cover, it could well be glued but even that can be overcome with perseverance. Sometimes though they are just impossible without something breaking. Link to comment Share on other sites More sharing options...
Brambles Posted February 12, 2010 Share Posted February 12, 2010 Just noticed you said you where bunging in 16 volts from your transformer which you said earlier was 1 Amp. If it was 16 volts connected then your batteries have high resistance and are kaput. Ahall assume there is confuson here and les see what yoru doscarge test shows. Still fascinated by this Moura battery - it is either an extremely good battery, or one bought in from another manufacture and just rebadged to complete the Moura range on offer. My feeling at moment is it is a Silver starter battery. Is there no other descriptions on the label like intelligent, leisure, LOG, or nuffink? Link to comment Share on other sites More sharing options...
spospe Posted February 12, 2010 Share Posted February 12, 2010 Tracker A couple of points: a) many batteries have translucent cases, enabling the level of the electrolyte to be checked without opening anything, is your Moura battery of this type? If not and if there are no removable plugs (sometimes hidden under sticky labels which cover the top of the battery), then you are stuck with what you have. b) A pedantic point (but being pedantic is one of the joys of life), Brambles said in his reply above: "will supply exactly the same power (current)". This is wrong; current is not the same as power. For example, a current of 2 amps at 12 volts equals 24 watts of power, whereas a current of 2 amps at 230 volts equals 460 watts; a major difference. Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 12, 2010 Share Posted February 12, 2010 No translucent cases Michael - sods law again - I already looked under the label as I've been here before with batteries! Currently on a discharge test and it does not look good. After 90 minutes with a 7amp discahrge (4 x 21 w bulbs in parallel) the Moura dropped from 12.95 no load / 12.45 under 7A load down to 12.30 no load / 12.1 with load. That seems a lot for what I calculate to be only about 126 watts (7 x 12 x 1.5) of use? Early indications are that the Elecsol is not faring much better and this more or less mirrors what happens on the van with it starting reasonable but very quickly falling away under load. Link to comment Share on other sites More sharing options...
Brambles Posted February 12, 2010 Share Posted February 12, 2010 spospe - 2010-02-12 3:31 PM Tracker A couple of points: a) many batteries have translucent cases, enabling the level of the electrolyte to be checked without opening anything, is your Moura battery of this type? If not and if there are no removable plugs (sometimes hidden under sticky labels which cover the top of the battery), then you are stuck with what you have. b) A pedantic point (but being pedantic is one of the joys of life), Brambles said in his reply above: "will supply exactly the same power (current)". This is wrong; current is not the same as power. For example, a current of 2 amps at 12 volts equals 24 watts of power, whereas a current of 2 amps at 230 volts equals 460 watts; a major difference. part b, you are being pedantic, I wrote power , but because the voltage might vary by a small amount decided to be more accurate and put current in brackets. Yes you are right, it is the current that will be identical. And the power which is volts times Amps will vary slightly depending on the voltage of the battery. Link to comment Share on other sites More sharing options...
Brambles Posted February 12, 2010 Share Posted February 12, 2010 your discharge on Moura is 10.5 Ah. (approximate and good enough for this purpose) 7 Amp x 1.5hours. It is totally Kaput. Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 12, 2010 Share Posted February 12, 2010 I don't mind anyone being pedantic when info is being given as it all helps! The results of the 90 minute 7 amp discharge on the Elecsol are almost identical so maybe both batteries are kaput after all? At the risk of displaying my ignorance what's the difference between watts (W) and amp hours (AH) please? If a battery has a theoretical capacity of 110ah is that not the same as 12v x 110ah = 1320w? Link to comment Share on other sites More sharing options...
spospe Posted February 12, 2010 Share Posted February 12, 2010 Rich (Tracker), there is a joke here! Having worked with batteries since 1961, I say with some feeling that when a battery is failing, the best thing to do with it, is replace it. Given that your test at the moment seems to indicate a lack of capacity, I would continue the test discharge until the on-load voltage reaches 11.5 volts. It is then just a case of multyplying the amps by the hours and that will be as near as dammit the capacity. I agree with Brambels that it does seem that the batteries have failed, but it will not cost you anything to run the test to its end point. You ask ........... "At the risk of displaying my ignorance what's the difference between watts (W) and amp hours (AH) please? If a battery has a theoretical capacity of 110ah is that not the same as 12v x 110ah = 1320w?" The simple answer is that you have just quoted two measures of battery storage capacity. Batteries have (as far as I know) always been quoted as having capacities of so many Ampere Hours, but they could just as easilly be quoted as having a power delivery of so many Watt Hours. Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 12, 2010 Share Posted February 12, 2010 Thanks for the info Michael - The batteries have just recoverd after an hour or so to 12.5 and 12.6 volts which looks good but I have the feeling would not last long under load? I agree with what you say that failing batteries really are not worth faffing about with in the long term as they tend to be more aggro than they are worth! I am happy - well almost - to buy two new batteries and will be delighted if that cures the problem. I will be less enamoured - well sick as a parrot actually - if buying two new batteries does not cure the problem so I will continue the test to the end to be sure! I did the same discharge test on my booster starter pack and although that only has a 20ah capacity a half hour run at 7 amps = 3.5ah - about 17.5% of it's theoretical capacity took the voltage from 12.82 to 12.42 - about 80% of it's capacity remaining - remarkably accurate I thought and further indicative of the Leisure batteries being Kaput. Mind you during that test the on load voltage was down to around 11.5v! Link to comment Share on other sites More sharing options...
spospe Posted February 12, 2010 Share Posted February 12, 2010 Tracker - 2010-02-12 5:58 PM I did the same discharge test on my booster starter pack and although that only has a 20ah capacity a half hour run at 7 amps = 3.5ah - about 17.5% of it's theoretical capacity took the voltage from 12.82 to 12.42 - about 80% of it's capacity remaining - remarkably accurate I thought and further indicative of the Leisure batteries being Kaput. Mind you during that test the on load voltage was down to around 11.5v! Rich, you need to be careful here as your statement above is potentially somewhat awry for the following reasons ..... a) Batteries are always quoted as having their quoted capacity at a particular discharge rate, usually for leisure batteries this will be the 20-hour rate. This is often shown as being the "I 20" rate, i.e. the current, which would totally discharge the battery in 20 hours. Thus a 110 a/h battery would have an I 20 rate of 5.5 amps. If a battery is discharged at a higher than its I 20 rate, it will seem to have a lower capacity. For example if the above 110 a/h battery was to be discharged at say 110 amps load, it would not last anything like 1 hour! If this battery were to be discharged at say 1 amp, it would last considerably longer than 110 hours. What this means for you is that your Booster Starter pack's battery of 20 a/h probably needs a load of about 1 amp if its capacity is quoted at the I 20 rate, not the 7 amps you have used. It is possible that the Booster battery could have its rate at a much higher figure than the I 20 rate because it is intended to be used in a short duration mode. This higher rate could be as high as the I 5 rate, meaning a load of 4 amps, but this is still much less than your test load. b) Calculating the residual capacity on the basis of voltage figures is very inaccurate and will lead to very misleading results. The only accurate method of measuring battery capacity is to use a hydrometer and note the readings. For example with a normal lead-acid battery, a fully charged state is indicated by an S.G. of 1.265, 75% by 1.225, 50% by 1.190, 25% by1.155 and a 'flat' battery by 1.120. What you must remember is that these figures do not tell you how much capacity a battery has left in terms of Ampere Hours; they only tell you the % of capacity remaining. This is becoming a lecture and I am going to stop now and go and watch "Nazi Hunters" on the PVR. Michael Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 13, 2010 Share Posted February 13, 2010 Thanks Michael I don't consider it a lecture - but then I find the whole battery subject fascinating anyway and I welcome all info - but not quite a nerd - yet! The only reason I tried the discharge test on the booster was to try and convince myself to spend upwards of £165 on two new batteries - but my tight streak is showing again and will until I am totally convinced! That said I am almost totally convinced and I just have to decide whether spending an extra £80 to £100 on the suggested Varta batteries would be justified. I need to be convinced or to convince myself that you really do get what you pay for and that the extra money is not just being charged to cover a fancy marketing and sponsorship budget. Then again I would rather have a Toyota than a Fiat if only because my perception is that Toyota are better made, longer lasting and more reliable in return for paying more which strikes me as a fair trade off! I did some current consumption tests this morning on the van and electrical items therein using the booster pack as a temporary leisure battery and I found that the readings were at odds with those taken a year ago, now being much less than then - except for the current draw with everything allegedly off which is much about the same at .018A which I think is 180 milliamps?. I suspect my multimeter to be wrong on amps and have ordered a new one as a double check but could it that the current consumed would be less on a good battery than on a duff one - I don't know eneough to know! The voltage shown using the booster pack as temporary leisure battery was 12.7 without the solar input and 13.5 with it on a dull morning. The solar current input showed as just 340 milliamps - if the meter is accurate. There is also a slight discrepancy on voltage between my meter which showed as .13V more than the Sargent display panel. I don't think that is enough to worry about in the real world but it could be making the batteries look slightly better than they really are! Thanks for you valued input as I'm never too old to learn a bit more. Link to comment Share on other sites More sharing options...
Brian Kirby Posted February 13, 2010 Share Posted February 13, 2010 Now for a real amateur moment! If the currents seem to have changed over time, might that be because the terminals were clean when the batteries were new? A bit of extra resistance has developed at the terminals this would also interfere with that charge rates. So, have you disconnected both batteries, cleaned and greased the terminals and connectors, and then re-connected all tight and clean? Obvious I know, but..........................?The usual safety precautions should be taken, of course! :-) Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 13, 2010 Share Posted February 13, 2010 Thanks Brian - yes the terminals were and are very clean but today's test was carried out with a booster battery pack as it is less aggro than refitting the two heavy leisure batteries and last years check was with the two leisure batteries in situ and in hindsight they were probably in a lower state of charge then than the booster pack is now. Todays test was with using croc clips instead of bolted terminals but nevertheless theay are clean and tight and the current flow was very low so I would not have thought it would make any difference - but I could so easily be wrong! At school I learnt the 'Watts is Volts times Amps' and on that basis if the voltage is lower then the current must be higher - I think! Confuse? You betcha! Link to comment Share on other sites More sharing options...
Keithl Posted February 13, 2010 Share Posted February 13, 2010 Tracker - 2010-02-13 12:39 PM - except for the current draw with everything allegedly off which is much about the same at .018A which I think is 180 milliamps?. Hi Tracker, I have been following this post with interest as a lot of very useful points have come to light, such as Equalisation charge which I had never heard of before. Anyway, my reason for posting is that things are actually far better than you fear as 0.018 A is actually only 18 milliamps. The conversion is 1000 milliamps = 1 amp. I will keep following with interest to see which new batteries you eventually buy, and whether you are then planning a discharge test on them to confirm their capacity? All the best, Keith. Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 13, 2010 Share Posted February 13, 2010 I stand corrected - again - Keith - many thanks - I always did have trouble with me decimal points - and I am glad that you too are learning a bit from this exciting saga! Link to comment Share on other sites More sharing options...
alan Posted February 13, 2010 Share Posted February 13, 2010 Hi Couldn't agree more with Tracker, this is an exciting saga. I was just about to put on a posting about leisure batteries when this thread appeared -can't thank you all enough for the help you've given me and Tracker's questions, of course! Alan Link to comment Share on other sites More sharing options...
Brambles Posted February 13, 2010 Share Posted February 13, 2010 Tracker, Will the Numax at 242mm high being taller than your existing batteries fit where you are placing them? Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 13, 2010 Share Posted February 13, 2010 Brambles - 2010-02-13 2:00 PM Tracker, Will the Numax at 242mm high being taller than your existing batteries fit where you are placing them? Thanks Jon, I had not got as far as checking heights - I looked at length and width and weight - but not height - duh! I think at 242 mm they might welll be too tall but I would need to check. Does that extra 50 mm height mean that the plates are larger and if so would that give an advantage in available power or durability worthy of consideration? Trust me to turn it into another question! Questions - always questions! Link to comment Share on other sites More sharing options...
Brambles Posted February 13, 2010 Share Posted February 13, 2010 Swings and roundabouts. There are no right or wrong ways - just different! to use your signature phrase. Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 13, 2010 Share Posted February 13, 2010 I can't get the lid off the Moura to check as although I can get the top cover to flex there sems no way to get the plugs to come out of any of the cells without destroying the top cover - although they must have gone in at some point - maybe with a barb to prevent nosey buggers like me from getting them out! It and I are continuing our ongoing 'discussion' as to whether it gives in or I do! The Elecsol has caps and after a long charge to around 13.0V and having been standing all day and now showing 12.9V the specific gravity of the cells is - 2 at 1.250, 2 at 1.240, 1 at 1.250 and 2 at 1.20. Not good methinks and further indicative that it (they?) are kaput as they both exhibit remarkably simlar charging and discharging charecteristics? This thread has become so useful as a source of information to me that I think I might print it all out when it ends for future reference and my thanks to all who have participated so far - anyone else care to add their tuppence worth please? Link to comment Share on other sites More sharing options...
Corky 8 Posted February 13, 2010 Share Posted February 13, 2010 Hi Rich, here is a link to the Lucas Battery web page, there is a double battery offer on the page , the two I bought are only 12 month old but have been fine , Dennis http://stores.shop.ebay.co.uk/Lucas-batteries-direct__W0QQ_armrsZ1 Link to comment Share on other sites More sharing options...
Guest Tracker Posted February 13, 2010 Share Posted February 13, 2010 Thanks indeed Dennis - wow, this looks like it is too good to be true - and you know what cynical old me thinks about that don't you! http://cgi.ebay.co.uk/PAIR-OF-PLATINUM-110AMP-LEISURE-12v-LEISURE-BATTERIES_W0QQitemZ280425582773QQcmdZViewItemQQptZUK_Campervan_Caravan_Accessories?hash=item414aaad0b5 I note that these too are 225 mm high! When I were a lad, Lucas auto electrical products were so good that they were known as 'Lucas - prince of darkness' and I still remember it! They seem to be called LC110 and appear to be on a par with many other 'less expensive' batteries? They weigh 24kgs each more or less the same and seem to be Calcium technology - whatever that is? Link to comment Share on other sites More sharing options...
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