big_kev Posted January 5, 2007 Report Posted January 5, 2007 OOPs ! Almost forgot to mention ............have you checked the obvious....swap youre battery with a mate's KNOWN GOOD ONE and see who ends up with the flat battery after a few days....only way to be sure ! I think you have a charging problem....let me know if I am wrong
Guest greenfingers Posted January 6, 2007 Report Posted January 6, 2007 Shucks, it's not the alternator. It was totally disconnected overnight, and this morning the voltage had still dropped .2Volts! Thanks for all your efforts, but the saga continues. I'm going to start disconnecting a few new things each night now, because it'll take till next Christmas if I try things one by one! I have already removed all non original wiring to the battery terminal (previous owner had a subwoofer and amp).The DVD player and screen are wired into the stereo circuit, so that if I pull the stereo fuse, they all switch off. I have had this fuse out overnight already, and it didn't make any difference.There are no other non factory bits in the car except the newish (fitted last August) towbar with twin electrics - now I'm suddenley thinking, could this be a factor, and if so how would I check?One thing in the fusebox which did puzzle me, was finding two fuses with an 'interior light' symbol, which seemed to have no effect on the interior lights. Instead there is a thickish red cable coming out of the loom, which has a push fit plug on it, and when unplugged, this turns off all the interior lights. My plan so far for tonight is: unplug the interior lights and stereo fuse, and leave the car unlocked without the immobiliser and alarm on. However, it seems unlikely to be any of these, since I have already done the ammeter test on them. Is it conceivable that a relay or circuit in the engine bay is the culprit? Is there anything else I could check?
big_kev Posted January 6, 2007 Report Posted January 6, 2007 OK I have re-read the thread again. Battery dropping 0.2v overnight, perfectly normal don't worry about it. Battery drawing 200mA...probably about right..clock..alarm system etc. Only issue seems to be battery going flat after a few days.Only 3 possible causes. 1: Faulty battery....you changed battery so that is unlikely. 2: Drain on battery...only showing 200mA so that is unlikley. 3:Battery not being charged sufficiently.... faulty Alternator...seems most likely ? Voltage reading is a guide but "a guide only"ie if alternator is not putting out 14+ volts it is definitly faulty.If it is putting out 14.4 volts it may still be faulty, diodes gone high resistance or similar.You will still get the voltage but no current to charge battery ( remember it is the current that charges the battery not the voltage ).eg you get several thousand volts out of your spark plugs and only a couple of hundred out you mains electrics which one will send the most electrons through your body ! ( please feel free to try this if you still disbelieve ) obviously the coil is very high resistance and can only deliver milliamps as opposed to the mains which can deliver a lot of amps . Only way to be sure is to use a known good battery and see if this still goes flat. Will be honest and say I am not 100% sure on the various battery types CA etc.Would advise to stick with original as the charging circuits may treat them differently...doubt it though.
Guest greenfingers Posted January 6, 2007 Report Posted January 6, 2007 Hate to admit that I may have previously misreported the readings, but when I pulled the stereo fuse this evening, the drain eventually dropped from 220mA to 100mA. Maybe the readings had been less accurate before, because I hadn't waited for everything to stabilise properley - since as soon as the ammeter is connected, it fires up all the circuits, and then bounces around for a while. Anyway, when I left it tonight the drain was 100mA, so tomorrow morning will tell if this 120mA difference will stop the battery going through a 20 per cent discharge. I would be very surprised though. Big Kev, if this does not make a difference, then tomorrow night I will put the battery from my van in - just to be absolutely sure that is not the problem.
Guest greenfingers Posted January 7, 2007 Report Posted January 7, 2007 Well, it did make a difference. The battery voltage dropped .13Volts over the same 15 hour period, instead of .20Volts.So with 55 per cent less drain (.1A instead of .22A), the voltage drops 35 per cent less than with the rad/cassette, CD changer and DVD connected. The relevance of these figures baffles me, but it does suggest that a drain of .1 or .2Amps is having a significant effect on the state of the battery - enough to discharge it in a few days. A number of people on this forum and elsewhere have suggested that this amount of drain should not run the battery flat so quickly, so after all my insistance and the battery supplier's that the battery is fine, I may have to eat my hat. Tonight, I will swap it with my van battery, and pray that this issue can finally be resolved!
Guest greenfingers Posted January 8, 2007 Report Posted January 8, 2007 I really don't get it, but this is my report this morning. Put the battery from my 02 reg Vivaro in at 3pm yesterday. It is a five year old 70Ah battery, and was only reading 12.45Volts when I put it in. Over a 19 hour period, with all fuses in place, it dropped to 12.37Volts, which is a drop of just .08Volts. This still seems too much, but for a smaller, old and partially discharged battery it did better than the new one!Previously I had been measuring the Sharan's new 88Ah battery voltage over a shorter 15 hour period, and it was dropping .2Volts. Before you all start screaming at me, yes I will take it back to the shop, but can anyone shed light on what might be happening?
seatkid Posted January 8, 2007 Report Posted January 8, 2007 Your "new" battery has internal (electrical) leakage - probably one cell...... Several possibilties:- Your "new" battery may have been on the shelf for some time before you got it. If it was stored "wet", these must be kept trickle charged to ensure they dont deteriorate. They also must not be dropped or subject to shock - this damages cells. Numax Batteries may be an inferior cheaper brand
Guest greenfingers Posted January 9, 2007 Report Posted January 9, 2007 At the risk of boring you all to death, here's the latest update. The battery supplier listened to my plight yesterday, and kindly offered to let me try another new Numax battery. So with new battery fitted, last night I did the voltage test at 6.30pm, and got a reading of 12.68Volts. I was so anxious to see if this was a cure that I went out at 9.10pm to see if there was any change. To my horror, it had dropped to 12.55. At 10.40pm it read 12.49, and then at 9.20 this morning it was still 12.49! In other words, the new battery made no difference (about .2V drop in 15 hours). Now I am really fed up this. However there may be a clue in the timing/discharge rate that may help diagnose this problem. My addled brain has almost given up with logic, but there are four things I would love answered:-1) What could drain the battery at a variable rate.2) Could it be due to the twin electrics for the towbar, which were fitted last August?3) Could it in any way be a result of having the cambelt changed last month?4) Is there any explanation which may point to relays behaving differently at different temperatures?
Andrew T Posted January 9, 2007 Report Posted January 9, 2007 Towbar wiring might be a good place to start, I recall this problem having been traced to newly fitted sockets before. It may you have been causing a drain all along but it's only become obvious with the greater demands placed on the battery by the winter weather.
Guest greenfingers Posted January 10, 2007 Report Posted January 10, 2007 Yesterday the towbar fitter told me where to find the fuse to disconnect the permanent live feed to the towbar. So I took it out. Did the usual measurements last night and this morning and guess what - still discharging :blink: Has anyone got any suggestions please?
mumof4 Posted January 10, 2007 Report Posted January 10, 2007 Buy a new car.... :blink: Ok.....at the risk of sounding stupid....one thing my tutor told me....if you cant find a fault.....start again...go slow...check absolutley everything....i mean..if you have a power drain in the house..what do you do.You turn everything off..then turn everything back on one thing at a time till you find the source.I know a car is a little bit different..what stays on when the car is locked.....led lights flash..clock..etc....what i usually do is make a list of things to check....
NikpV Posted January 10, 2007 Report Posted January 10, 2007 okay - what sort of quality is your meter - could it be reading a lower current than actual?? From this point - I think I've read the whole post - I would connect the battery in line with the ammeter and pull enough fuses to get the reading to 0 Zero nothing nowt. Then with this minimum number of fuses out do your overnight test. Assuming its not the battery (2 tried) and the charging circuit it must be the discharging side of things. A precautionary note: different make/design batteries may have varying discharge/p.d. curves (unlikely but possible I know because my 'A' level students used to investigate these for coursework) can you get a different make of battery rather than 2 of the same make?
mumof4 Posted January 10, 2007 Report Posted January 10, 2007 Apart from once when i left the car lights on overnight..i have never had a prob with my calcium battery and that is 3 yrs old...i think....lol...
Guest gooner52 Posted January 10, 2007 Report Posted January 10, 2007 i also have a bad battery drain checked it last night @ 23.30(11.30) :blink:reading 12.65volts checked it today @ 10.15am droped to 12.07..wallop so tonight gonna take the battery off the galaxy see how much she drops. whats the average amount the battery should lose thanks j :lol:
tim-spam Posted January 10, 2007 Report Posted January 10, 2007 I would agree with MO4 - go back to the basics. For example, you have not fitted the recommended battery for your car.....Also, does the second replacement battery actually go flat like the first one did?
Guest greenfingers Posted January 10, 2007 Report Posted January 10, 2007 Thanks everyone. The meter is a cheapo digital one, but I have used it successfully in the past. The battery is the same make as the previous new one, but other forum members have used Numax batteries without problems. I won't know if it will completely discharge over a few days unless we don't use the car - which is not feasible at the moment. I will do as suggested by Mo4 and NikpV, and remove all the fuses in an attempt to achieve the magic 0 figure - then see what happens............
Guest gooner52 Posted January 10, 2007 Report Posted January 10, 2007 quick update spoke to national tyres..they asked me to take the galaxy in to them today he said there was nothing wrong with the battery said it was 81% ok :lol: he tested the volts with engine running 14.04volts after a bit of talk,they changed the battery,new battery on engine running 14.23voltsquite a differnce there will wait and see how it goes,will report back :D first signs are good
seatkid Posted January 10, 2007 Report Posted January 10, 2007 Seesh....this thread is getting like one of those MO4 threads... :D Don't read too much into the minutiae of Voltage readings - those 0.10 volts are not that significant. Voltage on a car battery varies with lots of things..... temperature, state of charge, load, and time - when a load is removed, the voltage will rise over many minutes, when charging is stopped the voltage will fall over a hour or so. Seatkid has an Exide Ultra W017TE battery fitted (850A CCA, 95Ah, 4 year warranty plus an extra year negoiated and signed for...cost
Biscuit Posted January 10, 2007 Report Posted January 10, 2007 A car needs to be running for at least 20 minutes after starting just to replace the drain causedby starting the engine!how long are you running for after starting?biscuit
Guest greenfingers Posted January 10, 2007 Report Posted January 10, 2007 So greenfingers....... :rolleyes: ... I've been trying to avoid this.... :lol: ...what is the model ,year etc of your car? I will look up the electrics and give you a what to disconnect list (bit by bit) to try and isolate this mysteryosity.......no doubt it will be down to the washer leak under your carpet and soaking the ecu or remote...... I've had the offside front carpet up, and the floor is dry as a bone. The ECU is in the engine bay, also dry as a bone. Before you go to great lengths and sufference (I already feel guilty for being so demanding on the forum's resources), I will do as Mo4 and NikpV advised, and remove every fuse until that ZERO appears on the meter. If you really want to put a swift end to this tedium, here is the model info :-Sharan Tdi auto. Production date : 26/3/2001. Traceability no : 10457772.Type definition etc : 7M9 5T9 TRENDL4 85KW TDI AG5.Non factory extras : DVD, Towbar.
big_kev Posted January 10, 2007 Report Posted January 10, 2007 I am still finding difficulty seeing the problem here. The battery drops 0.2V overnight !This is normal and not a problem ! Does the battery continue to drop its voltage...if not don't worry Does the battery still start the car easily....if so don't worry Other than the battery voltage dropping overnight what are the other issues ?
Guest greenfingers Posted January 10, 2007 Report Posted January 10, 2007 If I park the car on a Friday evening, it won't start on Monday morning! (Unless it is used over the weekend). That is a problem isn't it?
big_kev Posted January 10, 2007 Report Posted January 10, 2007 Yep that is a big problem Just for reference mine had a problem ( relay 109, later changed and sorted ).However the temporary fix was to connect a direct feed to the fuel cut-off relay ( which was fred on ignition by relay 109, or would have been if it wasn't faulty ).This direct feed if left connected for a day was sufficient to totally drain a fully charged battery. I would not have thought that the little current required by the cut-off relay would have been sufficient to do this, however it was ( an in-line switch cured the problem, as long as I remembered to turn it off on a night ). OK back to the problem 0.2A for 24 Hrs = 4.8A per day = 9.6A per weekendThis is not going to drain your battery down too much.Unless of course it is not charging sufficiently in the first place. The symptoms would point to sudden failure of the charging system. The scenario is. Everything okSuddenly flat battery.Something has broken ( assuming no coincidal work taken place eg something new added very previously to failure ).Battery replaced with new one......no difference.No additional sudden drain found on battery ( 200mA is negligible )Almost certain then that charging system at fault.......! Can't see any other likely outcome
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