C5 OEM 0 Posted August 5, 2010 If its left for a few days needs to use jump leads and fires up straight away... measured battery after 3 days and 11.5v and turned over.. went to start this morning and dead...? checked battery and 11v`s... took battery out to charge but when checked the voltage it measured 14.5...? but still wouldn`t start...? just took the voltage straight down to 7-8v when i tried it..? The earth cable that bolts to the body was heavily corroaded,very green...could this cause the issues starting...it took a few tries with the jump leads to get it going... mainly reconnecting the earth lead in different positions... when the car is running it measures 18.5v andy Quote Share this post Link to post Share on other sites
Supercharged 2 Posted August 5, 2010 If you're seeing 18.5 with the car running then it's likely to be an alternator issue. You could take the battery to Halfords to be checked but I wouldn't buy a new one until the car has been looked at... Quote Share this post Link to post Share on other sites
dr_mat 0 Posted August 5, 2010 yeah, the alternator's output regulator has gone. putting 18.5v through a battery on a long term basis will somewhat knacker it. You can use such high voltages for very short periods only, if you're attempting to desulphate a degraded battery. step 1) new regulator (or whole new alt.), step 2) new battery..! Quote Share this post Link to post Share on other sites
C5 OEM 0 Posted August 5, 2010 so when i`m attempting to start it whats happening....? alternator draining it...? my work car was showing 18v when running...? so whats the deal with jump leads then.../ ? Quote Share this post Link to post Share on other sites
Supercharged 2 Posted August 5, 2010 my work car was showing 18v when running...? so whats the deal with jump leads then.../ ? Maybe your multimeter is screwed... If you can start it then just take the car to Halfords and get them to test the batt and car - the AA will also do this if you are a member. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted August 5, 2010 A screwed lead acid battery will show good volts, but hold no actual charge. A VR6 wanting to start will pull between 120 and 200 amps, the battery needs to be healthy. If your work car also shows 18v it either has a screwed alternator or you have a screwed voltmeter.. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted August 5, 2010 AH - have you got the metre on AC rather than DC? Quote Share this post Link to post Share on other sites
C5 OEM 0 Posted August 6, 2010 Just tested them both this morning..work car had 14v then 16.9 charging corrado had 10.5v then 20v when charging but went down to 16.9v when still charging...? andy ideas...? Quote Share this post Link to post Share on other sites
dr_mat 0 Posted August 6, 2010 Your votlmeter is telling you bullshit. Get another one. No lead acid car battery will put out 14v, ever. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted August 6, 2010 Yeah it's fooked - what does it show when you touch the 2 probes together? Quote Share this post Link to post Share on other sites
dr_mat 0 Posted August 6, 2010 Yeah it's fooked - what does it show when you touch the 2 probes together? My guess is it says "hey, dude, buy a new voltmeter"! It might be worth replacing the battery in it, see if that makes it speak sense. Quote Share this post Link to post Share on other sites
C5 OEM 0 Posted August 6, 2010 Got an old school friend to have a look at it... he fits alarms ect, battery read 9.5v and then 14.1 charging...he said 14.4v was ideal but 14.1 was ok. checked the amp drop and it only measured 0.2amps...tested by turning interior light and it went to .3amps and setting the alarm went to 10amp then back down to 0.2 So come to the conclusion that due to the car not being used alot its slowly drained the battery and weakened it...so on charge now and hopefully should be all working for sunday..?!! replaced battery in my multi-meter...!!! all working normal now..ha ha Quote Share this post Link to post Share on other sites
Supercharged 2 Posted August 6, 2010 Ah that explains it then! Nice one... Yeah 14.1V is fine - most I've measured only see 13.8V due to resistances of cables etc. 0.2A is quite a lot though - should be 0.05 to 0.09 Max (usually with an aftermarket alarm fitted) You may have a faulty window / central locking control unit - these seem to fail and draw an extra 0.1A all the time. A standard Corrado 54Ah battery will only last 270 Hours with a 0.2A drain, this equates to 11 Days although you probably won't be able to start the car after 7 and that's if the battery is good and fully charged when last parked up. (Should last 4-6 Weeks really!) Maybe buy a solar trickle charger if it's outside or a mains one if garaged... Quote Share this post Link to post Share on other sites
C5 OEM 0 Posted August 6, 2010 Ah that explains it then! Nice one... Yeah 14.1V is fine - most I've measured only see 13.8V due to resistances of cables etc. 0.2A is quite a lot though - should be 0.05 to 0.09 Max (usually with an aftermarket alarm fitted) You may have a faulty window / central locking control unit - these seem to fail and draw an extra 0.1A all the time. A standard Corrado 54Ah battery will only last 270 Hours with a 0.2A drain, this equates to 11 Days although you probably won't be able to start the car after 7 and that's if the battery is good and fully charged when last parked up. (Should last 4-6 Weeks really!) Maybe buy a solar trickle charger if it's outside or a mains one if garaged... how would i know if those have failed...? just pull the fuses and test the ampage...? my mate mentioned about the solar tricle chargers...have you ever used one..? Quote Share this post Link to post Share on other sites
KIPVW 0 Posted August 6, 2010 I use this one but only any good if you have mains in the garage, http://www.airflow-uk.co.uk/Battery-Conditioner.html a few others on here do too :wink: Quote Share this post Link to post Share on other sites
RW1 0 Posted August 7, 2010 I use this one but only any good if you have mains in the garage, http://www.airflow-uk.co.uk/Battery-Conditioner.html a few others on here do too :wink: Yup, had one since 1996 and still going strong. Bought a second cos it works well. An alternative is the Ring Automotive SmartCharge8 Code: RSC8 which will handle a Corrado battery. I have the SmartCharge4 version and it works well but will not shut off to cycling mode on a Corrado battery from experience. It's not powerful enough electrical output (amps) to charge a 50 amp plus battery hooked up to a Corrado. (Used on a 45 amp battery on another car and its fine.) . Quote Share this post Link to post Share on other sites
dr_mat 0 Posted August 7, 2010 There's also the optimate series chargers, also good. TBH no matter what the rating of the charger or battery, if you start from a reasonably well charged battery, it'll keep it sorted in the long term. If you expect to pull a flat battery back to life, you need to pay the money required to get a capable enough charger.. or use a bulk charger to do the grunt work then put it on a trickle charger to top it up or keep it fresh. Quote Share this post Link to post Share on other sites