F
franz47
850 TDI automatic 1996 with 265.000 km
Last year in summer 2008 before a trip through countries with sparse
Volvo-support possibilities I had my mechanic change the brushes-regulator-unit
of the alternator at about 240.000 km kilometrage. I was a bit under time
pressure so he could get hold only of one from a Volvo dealer, cost about 100
Euros more than from a "normal" shop, though probably the same product. I had
bought the car with about 210.000 km kilometrage and had no idea whether the
unit had been changed before. I did not want to get stuck because of worn
brushes. Befor winter I changed the battery - put in a new 75 Ah unit.
Now during summer I have the Eberspächer engine preheater on for about half an
hour in the morning, drive to work about 1 hour 80 km, then back home without
engine preheating the same distance, headlights low beam on during driving, air
condition fan, too. In my opinion that driving should be enough to charge the
battery after the engine preheating current loss in the morning. I was curious
how "charged" my battery actually was and connected my home charging unit, 10 A
max output. I was surprised that it took about 2 hours charging until the
charging current dropped to zero, did not measure voltage, but supposedly
14,something Volts.
So I decided to check the voltage at the battery terminals - according to Haynes
manual it should be 13,5 - 14,8 V during engine operation. The reading was at
idle rpm without anything turned on - 13,8 V, after turning on the headlights
13,7. When turning on all possible stuff - seat heaters, back window heater,
fan, high beam light etc, even with highers rpms the reading dropped to 13,4 V.
I tried to increase my wisdom on battery charging voltages:
http://www.batteryuniversity.com/partone-13.htm.
13,8 V would just fit the 2,3 Volts, but still is the lower limit.
Do I have a faulty regulator unit or does it behave as it should even at the
expense of submaximal battery capacity?
Any other comment on the values measured? Any other check I should do?
Franz47
Last year in summer 2008 before a trip through countries with sparse
Volvo-support possibilities I had my mechanic change the brushes-regulator-unit
of the alternator at about 240.000 km kilometrage. I was a bit under time
pressure so he could get hold only of one from a Volvo dealer, cost about 100
Euros more than from a "normal" shop, though probably the same product. I had
bought the car with about 210.000 km kilometrage and had no idea whether the
unit had been changed before. I did not want to get stuck because of worn
brushes. Befor winter I changed the battery - put in a new 75 Ah unit.
Now during summer I have the Eberspächer engine preheater on for about half an
hour in the morning, drive to work about 1 hour 80 km, then back home without
engine preheating the same distance, headlights low beam on during driving, air
condition fan, too. In my opinion that driving should be enough to charge the
battery after the engine preheating current loss in the morning. I was curious
how "charged" my battery actually was and connected my home charging unit, 10 A
max output. I was surprised that it took about 2 hours charging until the
charging current dropped to zero, did not measure voltage, but supposedly
14,something Volts.
So I decided to check the voltage at the battery terminals - according to Haynes
manual it should be 13,5 - 14,8 V during engine operation. The reading was at
idle rpm without anything turned on - 13,8 V, after turning on the headlights
13,7. When turning on all possible stuff - seat heaters, back window heater,
fan, high beam light etc, even with highers rpms the reading dropped to 13,4 V.
I tried to increase my wisdom on battery charging voltages:
http://www.batteryuniversity.com/partone-13.htm.
13,8 V would just fit the 2,3 Volts, but still is the lower limit.
Do I have a faulty regulator unit or does it behave as it should even at the
expense of submaximal battery capacity?
Any other comment on the values measured? Any other check I should do?
Franz47