Alternator problems?

aturi83 · 24th January 2018, 19:13

Hi guys having bother with starting, jumping the car, starting well and then driving without problems. No charge lights etc. Took it for a 2 hour drive to the midlands and back, radio/heater/heated seats etc all running. No hint of a problem.

Next day, flat as a ......

Jump it again, no issues drives fine.

Today had a chance to look over it. Battery has been on charge over night, so nice and fresh. Connected it to the car and checked voltage with a meter, found it was going UP.

Put multimeter in line, set to amps (10A) and it was drawing around 0.29, which is 290ma???

Checked the obvious things, interior lights etc, nothing there. Jumped the car, started no problems.

Took battery off the car tonight to mains charge it again. Couldn't turn the car over, put it on the charger.

Connected the multimeter and found the car had 0.5volts with the battery disconnected? Does this indicate alternator leak back. It had a new one a couple of years ago, not an OEM one unfortunately! - This explains why the battery voltage was going UP when i was checking it in situ.

Hopefully the answer is obvious to someone!

Devilish · 24th January 2018, 19:55

Sounds like a dead cell to me, hard to get a true drain reading if your battery is up the creek.

aturi83 · 25th January 2018, 11:21

Just checked the battery after an all night charge. Its at 12.85v. 5 minutes later it was at 12.83.... Going to give it a couple of hours. Whats it need to turn it over? 12.7 ish?

patrolman pete · 25th January 2018, 16:48

Voltage doesn't crank an engine , you need amps . When I test batteries at work , we measure available amps against the rated amps of the battery eg ( 540 amps EN) using a midtronics battery tester. A typical end of live battery may only have 1/4 of it's rated power but can be showing 12.4 volts. that'll put your lights on but won't crank your engine.

patrolman pete · 25th January 2018, 16:53

Quote:

Originally Posted by aturi83

Just checked the battery after an all night charge. Its at 12.85v. 5 minutes later it was at 12.83.... Going to give it a couple of hours. Whats it need to turn it over? 12.7 ish?

12.2 volts = 50% charged

12.5 volts = 75% charged

12.7 volts = 100% charged

aturi83 · 25th January 2018, 19:09

Quote:

Originally Posted by patrolman pete

Voltage doesn't crank an engine , you need amps . When I test batteries at work , we measure available amps against the rated amps of the battery eg ( 540 amps EN) using a midtronics battery tester. A typical end of live battery may only have 1/4 of it's rated power but can be showing 12.4 volts. that'll put your lights on but won't crank your engine.

Disconnected from the charger, sat in the garage its now at 12.66 volts.... Can the amps be checked with a multimeter??

COLVERT · 25th January 2018, 19:27

Quote:

Originally Posted by aturi83

Disconnected from the charger, sat in the garage its now at 12.66 volts.... Can the amps be checked with a multimeter??

Go up to the top of the main page and have a look at two posts I've put in the ----Really, really useful ----thread.

It will tell you lots about your battery and how and when to test it.---

COLVERT · 25th January 2018, 19:32

Quote:

Originally Posted by patrolman pete

12.2 volts = 50% charged

12.5 volts = 75% charged

12.7 volts = 100% charged

These figures are, of course, only a rough guide.

A half charged battery will easily start your car engine.

In fact during the winter months many cars are running around the roads with a half charged battery but will easily start up and run well.---

patrolman pete · 25th January 2018, 19:41

Quote:

Originally Posted by aturi83

Disconnected from the charger, sat in the garage its now at 12.66 volts.... Can the amps be checked with a multimeter??

Only amps you can check with the multimeter is the drain once the car has been locked up by connecting it between the negative post and the disconnected lead.

A good load test of a battery is to disable the engine ie unplug a fuel pump or pull out a fuse so that the engine will crank but not start. Then crank for 10 seconds and see if the cranking speed starts to slow which would indicate a failing battery. If it doesn't drop, the battery is still serviceable.

aturi83 · 31st January 2018, 07:37

Finally convinced Tayna batteries to send a replacement battery. Started first click and has done ever since. Touch wood, sorted! Why do we never just blame the battery first??!

24th January 2018, 19:13	#1
aturi83 Loves to post Peugeot 508 Join Date: Jan 2012 Location: Guisborough Posts: 255 Thanks: 9 Thanked 18 Times in 8 Posts	Alternator problems? Hi guys having bother with starting, jumping the car, starting well and then driving without problems. No charge lights etc. Took it for a 2 hour drive to the midlands and back, radio/heater/heated seats etc all running. No hint of a problem. Next day, flat as a ...... Jump it again, no issues drives fine. Today had a chance to look over it. Battery has been on charge over night, so nice and fresh. Connected it to the car and checked voltage with a meter, found it was going UP. Put multimeter in line, set to amps (10A) and it was drawing around 0.29, which is 290ma??? Checked the obvious things, interior lights etc, nothing there. Jumped the car, started no problems. Took battery off the car tonight to mains charge it again. Couldn't turn the car over, put it on the charger. Connected the multimeter and found the car had 0.5volts with the battery disconnected? Does this indicate alternator leak back. It had a new one a couple of years ago, not an OEM one unfortunately! - This explains why the battery voltage was going UP when i was checking it in situ. Hopefully the answer is obvious to someone!

24th January 2018, 19:55	#2
Devilish Been round the block 75 Tourer Join Date: Apr 2009 Location: Cannock Posts: 4,126 Thanks: 3 Thanked 189 Times in 121 Posts	Sounds like a dead cell to me, hard to get a true drain reading if your battery is up the creek. __________________ If at first you don't succeed, hide the evidence

25th January 2018, 16:48	#4
patrolman pete Posted a thing or two Rover 75 club se tourer CDT and a Connoisseur SE Diesel Auto Saloon Join Date: Nov 2006 Location: Houghton - le - Spring Posts: 1,422 Thanks: 618 Thanked 333 Times in 197 Posts	Voltage doesn't crank an engine , you need amps . When I test batteries at work , we measure available amps against the rated amps of the battery eg ( 540 amps EN) using a midtronics battery tester. A typical end of live battery may only have 1/4 of it's rated power but can be showing 12.4 volts. that'll put your lights on but won't crank your engine. Last edited by patrolman pete; 25th January 2018 at 16:50.. Reason: Error

25th January 2018, 11:21	#3
aturi83 Loves to post Peugeot 508 Join Date: Jan 2012 Location: Guisborough Posts: 255 Thanks: 9 Thanked 18 Times in 8 Posts	Just checked the battery after an all night charge. Its at 12.85v. 5 minutes later it was at 12.83.... Going to give it a couple of hours. Whats it need to turn it over? 12.7 ish?

31st January 2018, 07:37	#10
aturi83 Loves to post Peugeot 508 Join Date: Jan 2012 Location: Guisborough Posts: 255 Thanks: 9 Thanked 18 Times in 8 Posts	Finally convinced Tayna batteries to send a replacement battery. Started first click and has done ever since. Touch wood, sorted! Why do we never just blame the battery first??!