Load dump - Lifepo4 - Generator - battery charger

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At the same time got the quote on the hydraulic generator

HYDRAULIC GEN 3.5KW SINGLE PHASE
NO OUTLET $2,694.40

HYDRAULIC GEN 5KW SINGLE PHASE
NO OUTLET $3,444.80

Really are a nice set up, I could plug this into the gearbox with ball valve on-off
And remote mount on the other side of the bulkhead with the inverter charger feet away from it.

Would definately have this over a Balmar/Wakefield type arrangement.
 
A quote from a thread back in 2017.
Phil Fill said:
We have a 5KW cruise gen powered by the main 671. I had to re sheave/pulley on the 671 bigger to be able to maintain the required gen rpm at the cruise RPM of the main 671. One we are out in open water and will be cruising for hours at a constant 1500 rpm I switch to the cruise gen. In the marina and at slower speed use the main gen set which power the bow thruster and the get home. So the gen set is back up for the main 671 and the main 671 is back up for the gen set.

Cruise gen sets are some what popular on for sail boats and even small trawlers as an option. Our is a Auto-gen – 120/240 AC 60 Hz 5500 wt – requires minimum of 1750 RPM. Mfg by Mercantle Manufacturing company, Minden Louisiana.
Click to expand...

Some links to some other devices in that thread
https://www.trawlerforum.com/forums/s6/belt-driven-generators-12404.html#post190903
 
Simi 60 said:
Well, just had a quote come back from the generator shop that was selling these heads.
A 10kva Mecc Alte brand made in Italy and set up to be belt driven.

With outlet fitted, $395 + gst

Reckons he's sold plenty over the years, never had a return

10kva 50hz 240v is only 245mm wide and 460mm long

Think it'll be worth further investigation.
Click to expand...

Sounds pretty good. Which distributor was that? Does that include an AVR?
 
Simi 60 said:
Well, just had a quote come back from the generator shop that was selling these heads.
A 10kva Mecc Alte brand made in Italy and set up to be belt driven.

With outlet fitted, $395 + gst

Reckons he's sold plenty over the years, never had a return

10kva 50hz 240v is only 245mm wide and 460mm long

Think it'll be worth further investigation.
Click to expand...


If you decide to do this, either directly driven, or hydraulically drive, I'd be real interested to follow along with the project. I spent a little bit of time looking at a variant of this that you might want to consider.


As discussed here and elsewhere, the constraint with this approach is that you need to operate the engine at a specific rpm to get 50hz (or 60hz) power that will be usable my AC appliances. I know you are OK with that constrain, but at a minimum it will require switching the thing on/off when you are operating off-rpm, and there might be some risk of appliance damage if you forget. I personally didn't want something that required that much attention.


The alternative I considered was to rectify the AC to make DC, but it would be at a much higher voltage. It would end up in the 340VDC range with a 230VAC generator end, and you would use that as the DC power source for an inverter and for chargers. The Victron chargers can already operate off a DC power source, and there are high voltage inverters available as well - just not "marine" devices, whatever that means. The advantage of this approach is that the chargers and inverter would operate independent of main engine RPM.


In the end I didn't pursue it because it seemed to add up to a more complicated system without significant gain.
 
From the cheap seats here, it looks like the cheapest solution to the concern about BMS dump is as rslifkin said is a FLA battery, maybe behind an ACR. I have no dog in this hunt since I am sticking with AGMs on my smallish boat.
 
twistedtree said:
If you decide to do this, either directly driven, or hydraulically drive, I'd be real interested to follow along with the project. I spent a little bit of time looking at a variant of this that you might want to consider.


As discussed here and elsewhere, the constraint with this approach is that you need to operate the engine at a specific rpm to get 50hz (or 60hz) power that will be usable my AC appliances.
.
Click to expand...
Not with the hydraulic one you don't
Engine can be at any rpm and output is the same

I know you are OK with that constrain, but at a minimum it will require switching the thing on/off when you are operating off-rpm, and there might be some risk of appliance damage if you forget. I personally didn't want something that required that much attention.
Click to expand...

And I'm not convinced that should be an issue as the gen head is putting power into the inverter charger and the inverter would be powering the appliances , so that power should be clean if that's the right word?

The alternative I considered was to rectify the AC to make DC, but it would be at a much higher voltage. It would end up in the 340VDC range with a 230VAC generator end, and you would use that as the DC power source for an inverter and for chargers. The Victron chargers can already operate off a DC power source, and there are high voltage inverters available as well - just not "marine" devices, whatever that means. The advantage of this approach is that the chargers and inverter would operate independent of main engine RPM.


In the end I didn't pursue it because it seemed to add up to a more complicated system without significant gain
Click to expand...
Oh I agree, have read that several times and still can't get my head around it

Feeling a bit annoyed at the moment
Had never heard of the hydraulic Genset option before
Did some research and it sounds ideal
And found a second hand but seemingly unused one in Australia at an acceptable price

Contacted seller about it and he is in disbelief
Has been sitting there on the shelf for two years with no bites and now he gets 2 enquiries in week.
Seems I missed out by a day.
 
A lot of Nordhavn's early on were equipped with hydraulic alternators, and all, or nearly all have since been removed. I have no first hand experience with them, but complaints were that they put out a huge amount of heat, and that reliability and repair were problematic. But perhaps the more modern unit that was referenced in this thread will work better.
 
twistedtree said:
A lot of Nordhavn's early on were equipped with hydraulic alternators, and all, or nearly all have since been removed. I have no first hand experience with them, but complaints were that they put out a huge amount of heat, and that reliability and repair were problematic. But perhaps the more modern unit that was referenced in this thread will work better.
Click to expand...
Ah, ok, that's interesting
I would have thought hydraulic to be more reliable if anything
 
Simi 60 said:
Ah, ok, that's interesting
I would have thought hydraulic to be more reliable if anything
Click to expand...


I'm afraid I don't know any details about the actual problems people had, just that the satisfaction level was not good, and most have been decommissioned. But these are 15-20 year old designs, and perhaps the one that was linked in this thread is better.
 
Most inverters can only charge or invert, not both at the same time. So without 2 units, you wouldn't be able to charge without directly powering the AC loads.
 
twistedtree said:
A lot of Nordhavn's early on were equipped with hydraulic alternators, and all, or nearly all have since been removed. I have no first hand experience with them, but complaints were that they put out a huge amount of heat, and that reliability and repair were problematic. But perhaps the more modern unit that was referenced in this thread will work better.
Click to expand...



As the one who posted the original link I’d like to point out that I’ve only seen these hydraulic generators used on equipment that uses hydraulics for other functions. Equipment such as fire apparatus, utility boom trucks, dozers for high wattage lighting etc.

Understanding that a hydraulic driven generator is less efficient than one driven with a straight shaft the idea of using one on a passage maker has always intrigued me. If hydraulics are already being used for stabilization, windlass, boom etc why not also generate power? Would the loss of efficiency be made up from not having to run a separate engine while the main engine is running?

With the availability of large frame alternators and robust high wattage inverters is this the better approach?

John
 
To run a high wattage inverter I would think, would depend on the size of the battery bank. Yes? The math to how long do you want the batteries to last given a certain load. How long would it take to recharge that bank?

This maybe a case where lithium could be used?
 
Iggy said:
To run a high wattage inverter I would think, would depend on the size of the battery bank. Yes? The math to how long do you want the batteries to last given a certain load. How long would it take to recharge that bank?

This maybe a case where lithium could be used?
Click to expand...


Yes, but if you've got a big enough alternator supplying power while running, you wouldn't be drawing down the batteries while underway.
 
Investigating this some more, I only have the capacity to add a generator that would be driven by a sheeve with duplex 1/2" belts. Does anyone have links to a calculator that can tell me the max power that can be drawn from a 200mm/8" driven pulley, turning at 3000rpm and driven by these two 1/2" v belts?

By comparison, my old 10kva dunlite was driven by two 3/4" belts but at 1500 rpm. I'm guessing (with no supporting calculations) that I'll max out at ~5kva but it would be great to crunch some real numbers.

Thanks.

PS I forgot to add that belt wrap is 135°
 
GoneDiving said:
Investigating this some more, I only have the capacity to add a generator that would be driven by a sheeve with duplex 1/2" belts. Does anyone have links to a calculator that can tell me the max power that can be drawn from a 200mm/8" driven pulley, turning at 3000rpm and driven by these two 1/2" v belts?

By comparison, my old 10kva dunlite was driven by two 3/4" belts but at 1500 rpm. I'm guessing (with no supporting calculations) that I'll max out at ~5kva but it would be great to crunch some real numbers.

Thanks.

PS I forgot to add that belt wrap is 135°
Click to expand...

Load on belt before smoke and slippage is what you're after right?
I would have thought the supplier of the Genset head would have that info??
 
As to the comment about single RPM heads being no good or of limited use on a primary engine.

Our engine actually has a large mount/bellhousing on the front of engine
I am guessing at some stage it did have a large shaft driven generator which I believe, a lot of working trawlers have.
I wonder what they did as far as RPM control?

Add: maybe it wasn't a gen head, pic of another trawler, same sort of bell housing
Looks like hydraulics?

3996f157531b61a1b326cec808e5489c.jpg
 
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Simi 60 said:
I would have thought the supplier of the Genset head would have that info??
Click to expand...

I'm sure they can. However I've got a couple of other loads in the same belts so if I can find a calculator then I can also calculate the max load on the drive/crankshaft pulley too

Cheers

PS re your next post, I've had numerous different driven pumps etc off the front of my mains over the years esp when it was a commercial vessel: hydraulics, refrigeration compressor, steering hydraulics, various water pumps, most of which don't need accurate speed control. I don't think I've ever had a AC Genset though....yet ��
 
Last edited:
To address OP:
LiFePo4 batteries have a different 'charge Curve" and you will probably have to re-program your charge controller (I had to do this with my Victron Solar controller w/ 100Ah batt).
If you are worried about large volt spikes over contacts, we used to use capacitors across the relays in various applications like crankcase oil mist detectors. I would say go to one of the custom Audio shops for a 1-Fd can. Will soften the blow across the contacts. Just be sure to put a good phenolic cover.
 
johnrupp said:
As the one who posted the original link I’d like to point out that I’ve only seen these hydraulic generators used on equipment that uses hydraulics for other functions. Equipment such as fire apparatus, utility boom trucks, dozers for high wattage lighting etc. ...

John
Click to expand...

I have been interesting in the idea of hydraulic generators for some time. they just seen to make sense for many reasons. As you said, these generators are being used in vehicles and in applications where they have to be reliable.

Here is a list of suppliers I have found, many who have been in business for quite some time. Figured if they built a product that had quality issues, they would not have survived very long.


I found a European supplier but I can't find the link anymore. :banghead:

Later,
Dan
 
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