roaringgirl
Well-known member
There were a number of problems related to this particular application, where there's a battery isolator between the alternator output and the 2 separate battery banks:
1. The charge sense wire was attached directly to the output of the alternator. I have moved it to the house-battery post of the battery isolator.
2. Because the alt is behind the batt separator, the internal reg can't know the voltage of the batt, hence it needs to be externally regulated. I rewired the internals to bypass the internal reg, so the external reg can actually decide on the field voltage.
3. Inside the alternator there was a feedback loop (by design) so that once running, the reg took input from the alternator itself, so again, when behind a batt isolator, the alternator was not responding to the batt voltage, only its own output voltage. I removed this internal loop.
It is now giving 14.3V (as requested by the reg) and providing at least 40A (i don't have any more load I can give it right now, but it may provide more).
These are 3 reasons why this installation has never and could never have worked properly. It wasn't me so I can safely say that whoever installed it was a muppet.
1. The charge sense wire was attached directly to the output of the alternator. I have moved it to the house-battery post of the battery isolator.
2. Because the alt is behind the batt separator, the internal reg can't know the voltage of the batt, hence it needs to be externally regulated. I rewired the internals to bypass the internal reg, so the external reg can actually decide on the field voltage.
3. Inside the alternator there was a feedback loop (by design) so that once running, the reg took input from the alternator itself, so again, when behind a batt isolator, the alternator was not responding to the batt voltage, only its own output voltage. I removed this internal loop.
It is now giving 14.3V (as requested by the reg) and providing at least 40A (i don't have any more load I can give it right now, but it may provide more).
These are 3 reasons why this installation has never and could never have worked properly. It wasn't me so I can safely say that whoever installed it was a muppet.