Support Team Shaun_E Posted June 22, 2005 Support Team Share Posted June 22, 2005 I thought that I had solved my battery drain problem but apparently not. Although I could only measure a 13mA drain, my brand new (replacement) Red Top 15 battery is still losing charge. I bought a new Optimate charger/conditioner to keep it in good condition and it's fine with the charger connected. I left the car without the Optimate connected for 24 hours and the battery voltage has dropped to 12V - this is a huge reduction in the battery capacity so there must still be a large current drain and I must have not measured it properly ☹️. What are the most likely suspects? i.e. what should I disconnect to eliminate as the cause? I'm at the end of my tether on this . Who can I take the car to to get it fixed? Should I use a Cateham service agent or an Autoelectrician? Help please before I go off the car completely. Yellow SL #32 Link to comment Share on other sites More sharing options...
JampJ Posted June 22, 2005 Share Posted June 22, 2005 Connect a small bulb in series with the battery, then you can disconnect fuses etc. until it goes out. This may help find the problem. Cheers J&J Link to comment Share on other sites More sharing options...
Sheds Moderator Posted June 22, 2005 Share Posted June 22, 2005 I would start with the connection to the alty. Then one fuse at a time as suggested. Link to comment Share on other sites More sharing options...
Sheds Moderator Posted June 22, 2005 Share Posted June 22, 2005 Oh, obviously while doing this you leave the multitester in circuit between batt earth terminal and batt earth wire. Maplin's yellow multitester (a fiver, sometimes available with one free) is a great tool and small enough to carry everywhere if you want to. Link to comment Share on other sites More sharing options...
JampJ Posted June 22, 2005 Share Posted June 22, 2005 Maplins are doing a nice hand held MM for £6.99 reduced from £24.99 at the moment. Don't know if it's all stores. Shelf full in the Manchester branch. Cheers J&J Link to comment Share on other sites More sharing options...
Rob Walker Posted June 22, 2005 Share Posted June 22, 2005 Immobiliser especially if you leave the keys in the ignition with the Toad system Link to comment Share on other sites More sharing options...
Support Team Shaun_E Posted June 22, 2005 Author Support Team Share Posted June 22, 2005 I bought a good digital multimeter from maplins a few days ago to try and resolve the problem. With the multimeter in circuit it showed a current flowing of 13mA - I pulled every single fuse in turn and no change to the reading so I suspect the problem is the battery side of the fuse box. I'll try the alternator connection first then. I presume the immobiliser (standard Rover MEMS) draws the same current whether armed or not. Yellow SL #32 Link to comment Share on other sites More sharing options...
LazerBrain Posted June 22, 2005 Share Posted June 22, 2005 I don't think there was much difference in current between the immobiliser being armed or not when I tested recently. I'm also sure my current reading went down to zero when I pulled the ECU fuse... cheers, Darren. Link to comment Share on other sites More sharing options...
Mike Molloy Posted June 22, 2005 Share Posted June 22, 2005 IIRC the 5AS immobiliser still draws quite a lot of juice in standby - around 10mA. Pull the grey plug out and re-check your current drain (won't do any harm, but you probably will have to re-sync the keys afterwards). I would recommend a battery conditioner if the car is left unused for more than a few days. Link to comment Share on other sites More sharing options...
Sheds Moderator Posted June 22, 2005 Share Posted June 22, 2005 Calculations show that a 13mA drain will take 96 days to kill a 30 Ah battery. Even a partial discharge (say 20%) will take 19 days and the battery should handle this. Are you sure the battery isn't, like Howling Wolf, "going down slow"? Link to comment Share on other sites More sharing options...
Support Team Shaun_E Posted June 22, 2005 Author Support Team Share Posted June 22, 2005 Quick potted history: 1. Car left without conditioner for 3 weeks - 4 week old Red Top 15 battery goes flat 2. Recharged battery and now made sure that I put it on the conditioner when not in use 3. Go away for weekend with car and car not driven for 48 hours (boozy weekend 😬) - battery goes flat 4. Get home and recharge - battery will last 24 hours but not 48 5. Buy multimeter and test current drain - only 13mA so should be OK for weeks without conditioner 6. Battery manufacturer (DMS) say that letting it go completely flat will have reduced it's capacity - I buy new battery and an Optimate charger/conditioner 7. Drove car and left without conditioner for 24 hours - new battery drops to 12V So basically my measurement of 13mA must be complete rubbish. This was between the battery earth terminal and the earth strap. I will re-measure the current drain again tonight but either it is an intermittent fault or I just can't read an ammeter . Assuming I can finally measure a high current drain I need to look for potential sources. I'll start with pulling all the fuses again and failing that check the alternator and starter connections. If I still can't find it then I am going to have to call in a professional . Oh and anyone want to buy a 2 month old Red Top 15? Yellow SL #32 Link to comment Share on other sites More sharing options...
LazerBrain Posted June 22, 2005 Share Posted June 22, 2005 If you are measuring current using one meter probe to the battery -ve and the other to the ground cables removed from it (ie no other connections to the battery -ve terminal) then that's correct. Perhaps you could repeat step 7 with the battery disconnected and see if it still drops to 12v? I might have some free time on Sunday if you want a 2nd pair of eyes, but I've not spent time checking over starter/alternator problems before. cheers, Darren. Link to comment Share on other sites More sharing options...
Sheds Moderator Posted June 22, 2005 Share Posted June 22, 2005 Loads of stuff on batts and alts in FAQ, top right. If it's dying in 24 hr and you measure 13mA, the batt is US. If you discon it totally and charge it overnight, what is it 24 hr later? This will give you your answer. Also, what is the voltage across the batt when cranking? If under 9V, goodnight Vienna. Link to comment Share on other sites More sharing options...
Support Team Shaun_E Posted June 22, 2005 Author Support Team Share Posted June 22, 2005 BOSS - thats what I don't understand . I measured 13mA yet the battery still drains. The battery is brand new. I put it on charge when it was delivered and then fitted it. Cranking is fine - even after 24 hours and a drop to 12V it still starts the car easily. I have the previous battery sitting in the garage so will check the voltage on that but suspect that it will be fine too and that I wasted my money replacing it. Darren - thanks for the offer but I'm not around on Sunday. I will be trying to fix it again tonight and will post back on here with my results. Somehow, between me reading the 13mA and closing the garage door the Amp pixies arrive and start draining the battery. ☹️ Wish me luck! Yellow SL #32 Link to comment Share on other sites More sharing options...
Pooh_R Posted June 22, 2005 Share Posted June 22, 2005 It seems suprising that the current is such a constant 13mA. As already stated this current shouldn't drain a new (healthy?) battery in 48 hours. Is it worth checking the meter and measurement procedure are both working correctly? e.g. a 60W headlight would draw about 5A. I second the suggestion to check the voltage after 24 hours with the battery disconnected, and in addition, check the cranking voltage. Good luck! Pooh A Bear of little Brain! Link to comment Share on other sites More sharing options...
zak Posted June 22, 2005 Share Posted June 22, 2005 Hi Shaun, I had a similar problem. Wasted money on two batteries and then got a trickle charger 12 volt socket wired in. Dont remember to use it. My solution was to get a battery cutout wired in. I decided to go round the problem - besides its not a bad idea to have one anyway. Zak www.zak7.com Link to comment Share on other sites More sharing options...
Colin Mill Posted June 22, 2005 Share Posted June 22, 2005 Hi Shaun Just on the offchance that the battery is a duffer and if you have not already tried it, it could be worth standing the battery disconnected for 48 hours after charging it and see if it can then crank the motor. Link to comment Share on other sites More sharing options...
Support Team Shaun_E Posted June 23, 2005 Author Support Team Share Posted June 23, 2005 Thanks for all your suggsetions here's an update: Left the ammeter in series with the battery for several hours last night and the reading wavered between 16 and 17mA - the difference being that the immobiliser was armed this time - I guess the flashing LED was causing the fluctuation. I removed each fuse one at a time and found that removing the flasher unit fuse (or the unit itself) dropped the current draw by about 3mA - I will get a new flasher unit just to be sure. I checked my previous battery that has been stood for a week and that was reading ove 13V so I have indeed wasted my money on a new battery. I have left the new battery disconnected so will see what happens to that. Zak - I think a cut off switch may be my only (easy) solution. If I fit this according to the instructions there will still be power to the ECU - might this still cause a problem? How did you fit yours? I will check the ammeter is OK. I will check the cranking voltage again but it was over 9V last time I checked it. Yellow SL #32 Edited by - Shaun_E on 23 Jun 2005 08:27:13 Link to comment Share on other sites More sharing options...
Ferrino Posted June 23, 2005 Share Posted June 23, 2005 J&J - do you know if this discounted Maplin multimeter is available from the website? I can't seem to spot it...... cheers. Bite me 😬 Link to comment Share on other sites More sharing options...
cat boy Posted June 23, 2005 Share Posted June 23, 2005 Hi shaun Had probs with my batt a few weeks ago, old batt no good got new batt wouldnt start ,AA checked new batt that was sh*ged rest of the car was fine 2nd new batt now fine. Any way when switching off ignition their is an electrical buzzing from engine bay untill i switch off batt master switch. Dont know if this helps but that buzzing has got to be a drain??? Any way good luck cat boy Ex acadamy car 2002, yellow and black 😬 Link to comment Share on other sites More sharing options...
JampJ Posted June 23, 2005 Share Posted June 23, 2005 Ferrino, the meters are in the Manchester, Oxford road branch. 0161 237 1977. Don't know if they are in the reduced catalogue, I haven't got one. It's a UT30, NOOBX Palm size digital multimeter. Cheers J&J Link to comment Share on other sites More sharing options...
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