Battery slow to charge? -Bit of winter advice.... maybe?

[Bowie69]

Finally got round to fixing a problem on my RRC this weekend, I was only getting 13.5/13.6V at the battery whilst running (yes, even at 2000rpm) -which as anyone will tell you is no good for the battery.

I traced the fault down to slightly grubby ring connectors on the :

• Alternator
  
• Through-bulkhead connection bolt
  
• Starter motor
  

The connectors were NOT corroded badly, or muddy, or green, or fluffy white, just not bright metal. Measuring from the back of the alternator to earth gave me 14.1V, bulkhead connector to earth was 13.8V, and starter to earth was 13.5/6V, so clearly voltage was escaping in the connections -not good long term as heat will built up in them causing them to fail (catch fire!).

I also checked the earth in the same way (though only two connection points, chassis and engine) and found them to be good, only losing 0.1V

Once I had cleaned all these up with some contact cleaner and green brillo to avoid removing the plating, I had 14.03V at the battery terminals, and given that it was pretty discharged is a good result.

So... half an hour with a bit of cleaner and brillo may mean it will start in the cold this winter

[robhybrid]

have you ever tried attaching a multimeter(set to voltmeter) on the positive line i.e black at battery + and red at the alternator +,

I guess in your case it would have read 0.5 V when you would be looking for 0.1V or less.

[Bowie69]

Yes, it was doing exactly that between battery positive and alternator stud