DC to DC charger - not needed for boats with proper alternators.

[Pete7]

Originally Posted by terry298656

DC to DC charger - not needed for boats, not all

Well I disagree. I have the Victron DC>DC and its handy at keeping the lid on a standard Valeo alternator so it doesn't self destruct.

Pete

[sailorboy1]

and here I thought this thread topic was fully answered 100 posts ago

[Ballsnall]

Originally Posted by sailorboy1

and here I thought this thread topic was fully answered 100 posts ago

Thread topic is wrong, should have read.

DC to DC chargers not needed on boats with,

High output alternators
AND
External regulation
AND
Temperature sense control
AND
Serpentine belt drive
AND
HVD protection
AND
Does NOT have a small engine.

For everyone else they are fine to use.
See, a simple change of heading could have resolved so much disagreement.

[hjohnson]

Originally Posted by Ballsnall

Thread topic is wrong, should have read.

DC to DC chargers not needed on boats with,

High output alternators
AND
External regulation
AND
Temperature sense control
AND
Serpentine belt drive
AND
HVD protection
AND
Does NOT have a small engine.

For everyone else they are fine to use.
See, a simple change of heading could have resolved so much disagreement.

I'd simplify that to just "external regulation"

I have a comparatively small output alternator (85A hitachi) running on a tiny engine (Yanmar 1GM10) with a standard v-belt and the combination works beautifully, mostly because the alternator can manage the load on the engine, especially at low RPMs. Thus, when I'm putt-putting into a marina or into an anchorage, the alternator is putting basically zero drag on the engine.

[Ballsnall]

Originally Posted by hjohnson

I'd simplify that to just "external regulation"

I have a comparatively small output alternator (85A hitachi) running on a tiny engine (Yanmar 1GM10) with a standard v-belt and the combination works beautifully, mostly because the alternator can manage the load on the engine, especially at low RPMs. Thus, when I'm putt-putting into a marina or into an anchorage, the alternator is putting basically zero drag on the engine.

You will need more than just external regulation with a "proper alternator" although with your engine you would have to forego propulsion I would suspect. What size lithium bank do you have?

[hjohnson]

Originally Posted by Ballsnall

You will need more than just external regulation with a "proper alternator" although with your engine you would have to forego propulsion I would suspect. What size lithium bank do you have?

I've had my system on the boat for 1.5 years, it works perfectly. I've got a 460Ah 12v bank, managed by a REC ABMS. This controlls the Wakespeed WS500 beautifully.

I have the WS500 to slowly ramp up the power starting at about 1200rpm and achieving full power by 2800rpm, though I also use the feature-in port to limit the field current to 50% most of the time. This generally means I get about 45A out of the alternator, which is more than enough for most purposes.

If I need to dump a lot of power into the battery, I flip the switch, and the WS500 now will hapilly pump between 75 and 80A into the battery, but probably limits me to 4kts rather than my 5.5kt hull speed (and it really works the engine hard if I'm not in neutral).

We will likely eventually repower with a Beta 16 engine and order it with the 120A alternator, but for now what we have works better than I could have ever expected.

[Ballsnall]

Originally Posted by hjohnson

I've had my system on the boat for 1.5 years, it works perfectly. I've got a 460Ah 12v bank, managed by a REC ABMS. This controlls the Wakespeed WS500 beautifully.

I have the WS500 to slowly ramp up the power starting at about 1200rpm and achieving full power by 2800rpm, though I also use the feature-in port to limit the field current to 50% most of the time. This generally means I get about 45A out of the alternator, which is more than enough for most purposes.

If I need to dump a lot of power into the battery, I flip the switch, and the WS500 now will hapilly pump between 75 and 80A into the battery, but probably limits me to 4kts rather than my 5.5kt hull speed (and it really works the engine hard if I'm not in neutral).

We will likely eventually repower with a Beta 16 engine and order it with the 120A alternator, but for now what we have works better than I could have ever expected.

Sounds like a great setup on a small engine. 80A from a 85A alternator is impressive.

[hjohnson]

Originally Posted by Ballsnall

Sounds like a great setup on a small engine. 80A from a 85A alternator is impressive.

What makes it possible, I think, is that the alternator is essentially floating in free space. Because it’s a single cylinder, there’s no exhaust manifold or heat exchanger blocking airflow into the back of the alternator. It has great ventilation.

Also, it probably helps that when the guy who rebuilt and modified the alternator, he put in a rectifier that would normally be used on a 120A alternator, so its cooling is a bit oversized.

[Ballsnall]

Originally Posted by hjohnson

What makes it possible, I think, is that the alternator is essentially floating in free space. Because it’s a single cylinder, there’s no exhaust manifold or heat exchanger blocking airflow into the back of the alternator. It has great ventilation.

Also, it probably helps that when the guy who rebuilt and modified the alternator, he put in a rectifier that would normally be used on a 120A alternator, so its cooling is a bit oversized.

Still an amazing result and thanks for sharing as it really helps others looking for real world solutions especially on small engines.

[Fuss]

Well, that’s it now, I unplugged the alt temp sensing wire from the regulators, the 2 alternators are running at around 140 degrees C, they seem happy enough.
I didn’t realise that many of you here had plastic alternators, of course with these you would need a dc to dc chargers. No wonder you all got so upset.
Anyway , my proper alternator , made of steel and aluminium with roller bearings is behaving just like it did in the old days before lithium.

[hjohnson]

Originally Posted by Fuss

Well, that’s it now, I unplugged the alt temp sensing wire from the regulators, the 2 alternators are running at around 140 degrees C, they seem happy enough.
I didn’t realise that many of you here had plastic alternators, of course with these you would need a dc to dc chargers. No wonder you all got so upset.
Anyway , my proper alternator , made of steel and aluminium with roller bearings is behaving just like it did in the old days before lithium.

It generally doesn't matter what the alternator case is made out of, virtually all of them are metal. But for most alternators, that kind of heat is going to rapidly break down and destroy the electrical insulation in both the stator windings and rotor windings. You need to be absolutely sure that your alternator is spec'd for those temperatures, as I've not ever seen one that is.

Either way, though, even if you need to limit the temperature to 100c, you don't need a DCDC converter, you just need a suitable regulator.

[newhaul]

Originally Posted by Fuss

Well, that’s it now, I unplugged the alt temp sensing wire from the regulators, the 2 alternators are running at around 140 degrees C, they seem happy enough.
I didn’t realise that many of you here had plastic alternators, of course with these you would need a dc to dc chargers. No wonder you all got so upset.
Anyway , my proper alternator , made of steel and aluminium with roller bearings is behaving just like it did in the old days before lithium.

And will you tell us when they fry the electrical varnish on the wire won't stand up for long at that kind of heat.
Most electrical varnish has a melting point of 150°C and will breakdown rapidly anywhere near that temperature

[noelex 77]

Originally Posted by Fuss

Well, that’s it now, I unplugged the alt temp sensing wire from the regulators, the 2 alternators are running at around 140 degrees C, they seem happy enough.

Routine temperatures of 140°C or 284°F are too high for long term reliable operation.

[Fuss]

they are more than 1500hrs old… do we now want to discuss that with lead they did not get that hot. i measured after 30 mins and 1 hr, both were at the hottest spot 130 on 1 and 140 on the other.
that’s what bulk is all about … full output and as i said before they did this often with lead in the past and now lithium.

see, it’s clear , plastic alternators can’t handle heat, that’s why you don’t understand…

[CaptainRivet]

Originally Posted by newhaul

And will you tell us when they fry the electrical varnish on the wire won't stand up for long at that kind of heat.
Most electrical varnish has a melting point of 150°C and will breakdown rapidly anywhere near that temperature

Exactly. The isolation lacquer of the coils starts to deteriorate at 120-140C. Its well known that you reduce the lifespan by half of your alt each 10degrees above 110C coil temp.
Yes they are as always some exceptions with very low rpm high amps that have a higher temp range but these are mid 4 digits price tag.
But let him ruin his alts and LFP starter....all told him its a bad idea but well he doesn't listen. Will get a very expensive lessons learned, hope the boat is not burning down...