Dashboard Alternator light
Hi all, The MPPT controller on my coach will deliver 14.6 volts in bulk mode which is fine. In fact it’s exactly what the specs on my GC2 house batteries call for. But when I turn on the engine and...
Forum Discussion
eric,
Alternators are rated in amps. Mine is 130 amps. However they are not made to run 'flat out'. The "usual" number (so I'm told by others) is about 1/3 continuous. So my 130 amp alternator can really only provide about 43 amps continuous. Of course, some amps are needed to keep the engine and other devices working.
There ARE continuous output alternators, but they may be a big chunk of change.
There are also external diodes that can be added on. But that is beyond my skill set.
That is why one needs to know the peak output of the alternator--and then not take it up to that for very long.
Generally with modern vehicles the computer (ecu) decides what alternator output needs to be to recharge the chassis battery after starting. That doesn't take very long, so house bank charging is often slow.
I do have a dc to DC charge controller--but it is not yet installed. I chose to use one that is limited to 20 amps output, because the input may well be 30 amps. The dc to DC boosts the voltage so that the house bank will charge faster. In other words, it over rides the ecu and draws more amps from the alternator. It does this by raising the output voltage--so more amps will flow.
Renogy makes one that is a 40 amp output--but which has a jumper that can be removed to limit it to 20 amps.
If you want a "top drawer" device Victron makes one, too.
BFl13 has a unit from Renogy and it works well for him.
Alternators are rated in amps. Mine is 130 amps. However they are not made to run 'flat out'. The "usual" number (so I'm told by others) is about 1/3 continuous. So my 130 amp alternator can really only provide about 43 amps continuous. Of course, some amps are needed to keep the engine and other devices working.
There ARE continuous output alternators, but they may be a big chunk of change.
There are also external diodes that can be added on. But that is beyond my skill set.
That is why one needs to know the peak output of the alternator--and then not take it up to that for very long.
Generally with modern vehicles the computer (ecu) decides what alternator output needs to be to recharge the chassis battery after starting. That doesn't take very long, so house bank charging is often slow.
I do have a dc to DC charge controller--but it is not yet installed. I chose to use one that is limited to 20 amps output, because the input may well be 30 amps. The dc to DC boosts the voltage so that the house bank will charge faster. In other words, it over rides the ecu and draws more amps from the alternator. It does this by raising the output voltage--so more amps will flow.
Renogy makes one that is a 40 amp output--but which has a jumper that can be removed to limit it to 20 amps.
If you want a "top drawer" device Victron makes one, too.
BFl13 has a unit from Renogy and it works well for him.
