Alternator problems?

[aturi83]

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]

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

[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?

[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.

[patrolman pete]

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]

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]

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]

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.---:eek:

[patrolman pete]

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]

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??!

[COLVERT]

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??!

I always do---------------------:D:D:D

[slovcan]

I always do---------------------:D:D:D

On my bike forums we always say IATB{It's Always The Battery}(unless it's the carbs) :D .

[COLVERT]

On my bike forums we always say IATB{It's Always The Battery}(unless it's the carbs) :D .

Not the Honda CB 1,000 forum by any chance ???

[slovcan]

Not the Honda CB 1,000 forum by any chance ???

No, but I did have a CB900 Custom I bought new in 1982. The forums are V4Hondabbs and V4Musclebike. Lots of us are members on both.

Cheers,
Glenn

[MSS]

..............Why do we never just blame the battery first??!

We normally do! :D;)