vic008
Well-Known Member
My sparky says too slow. No room for bigger crank size, and cant go smaller on alt due to oil filter in the way. Anyone have a way around this? Mount alt differently?
VP 2003 alt speed
- Thread starter vic008
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Tintin
Well-Known Member
Is it as originally installed?
And is he saying too slow because of a charging issue?
And is he saying too slow because of a charging issue?
vic008
Well-Known Member
Yup original set up.
Am told alternator needs to spin at about 2500 to really do anything.
Am told alternator needs to spin at about 2500 to really do anything.
[70521]
Well-Known Member
What voltage is it producing? How many amps are the batteries absorbing?
vic008
Well-Known Member
14.4 v Sometime run engine for an hour and do 40a going down to 6a Sometimes go whole hour at 6 or so amp
Tranona
Well-Known Member
That is because your battery is close to full and that is all it will accept. Nothing to do with the alternator speed, although obviously the higher the engine revs the greater the output. What you are experiencing is quite normal. If you have a charge system that charges the engine start system first you will get high output just after the engine starts then it will fall away to the level that the batteries will accept.
Worth fitting a battery monitor if you have not got one already. This will help you understand your power consumption, charging and battery state of charge.
Worth fitting a battery monitor if you have not got one already. This will help you understand your power consumption, charging and battery state of charge.
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simonfraser
Well-Known Member
yep, mine charges at full power when revs on my engine are 1k and over
a shunt, such as victron provide will show you what is going on
RichardS
N/A
We don't know who your "sparky" is but I'd suggest that you find a new one asap as I've rarely heard such tosh.
Richard
black mercury
Well-Known Member
The alternator on a 2003 will be doing 2500 rpm when the engine revs are at 1450 or thereabouts.
An older dynamo will certainly produce a greater current the faster it turns, not so much an alternator.
An older dynamo will certainly produce a greater current the faster it turns, not so much an alternator.
TernVI
Well-Known Member
Is it getting to 14.4V straight away?
It's quite common for old spec alternators to be current limited and not get to 14.4V at low revs while the battery (or other loads) are taking several amps.
If the battery is getting to 14.4V straight away, then you don't have an alternator problem.
It can be a big ask to expect 14.4V immediately at idle RPM. You may either have to accept giving it a few minutes to get there, or giving it more RPM. If the only gain to be had is reducing your engine run time by a few minutes a week, it may not be worth doing anything.
If you run a lot at low RPM on a river or something, you might gain by changing things.
One boat I had, the original Yanmar alt only made 14.2V and needed 2000RPM of engine to make 14.2V and 25A at the same time. As we were charging house batteries and didn't have much solar back then, we made real improvements with a better alt.
I suspect you may not have done your 'sparks' fair justice?
Tintin
Well-Known Member
That seems fine to me.
I had a 2003. 240amp battery bank. Fitted an Adverc charge controller to charge faster, and replaced diodes block with a VSR.
pvb
Well-Known Member
An Adverc (or other add-on regulator) will compensate for any voltage drop at the diode splitter, so there's no real need to change it for a VSR.
Tintin
Well-Known Member
True.
