48v alternators

[IanD]

1 hour ago, cuthound said:

The smallest (and most common are in the 10-25kVA range. Most telephone exchanges (which are rapidly being lost due to VOIP) are small rural ones.

 

I agree larger ones (up to 3MVA) and often based on ship propulsion diesel engines would be to large as they are bigger than even a full length narrowboat.

But in reply the OP said 10kVA was too big for him... 😉

 

(probably physical size as well as power)

Edited October 18, 2022 by IanD

[cuthound]

21 minutes ago, IanD said:

But in reply the OP said 10kVA was too big for him... 😉

 

(probably physical size as well as power)

 

Strange, I thought he had a 14 hp engine and wanted electric drive. 14hp is about 10kVA at unity pf.

Edited October 18, 2022 by cuthound
To unmangle the effects of autocorrect.

[Antrepat]

2 hours ago, cuthound said:

Which is why I suggested to OP looked at ex-BT gensets. Cheap, reasonably well maintained and usually very low hours (typically 12 per annum).

@cuthound: I don't suppose you have any links to post to brokers selling these?  When I looked, all I could find were clapped-out builders' generators and giant ones for backing up hospitals.

[IanD]

21 minutes ago, cuthound said:

 

Strange, I thought he had a 14 hp engine and wanted electric drive. 14hp is about 10kVA at unity pf.

Being picky, about 9kVA allowing for 85% efficiency... 😉

 

If it's an AC generator (like the ex-BT ones) then something like a Victron Multiplus/Quattro is needed to charge the LFP batteries. Even the 48/10000 models can only charge at 100A maximum which is 7kW and cost getting on for £4k each, which is likely to be out of the OPs budget. For a 10kW generator he'd need the 48/15000 which costs even more... 😞

 

(or just don't use the full output of the generator)

 

Since he (unusually!) seems to want high power mainly for propulsion and battery charging not running 230Vac gear on the boat, a 48V DC generator plus a much smaller inverter would probably be the best solution, the problem is finding one (new ones are scarce and expensive) or building one (needs significant electrical system design skills).

 

Having several DC sources (generator/alternator/solar/charger) all of which need controlling presents several problems, some obvious and some not so obvious, to prevent possible battery/component damage under all circumstances -- overcharging from solar, protection against a battery disconnnect/alternator load dump, battery over/undercharging, temperature protection of battery and alternator. I know people like nicknorman are aware of all these issues and capable of designing a system to deal with them, but it's not as easy as it first appears.

 

It's why the more conventional (but expensive) route is to have a master controller which oversees everything including battery management, alternator charging, protection, MPPT control, and where an AC generator is just another input to deal with, and the core of the system is a big inverter/charger like a Victron, often with an external controller like a Cerbo. It's not cheap but it works and has been extensively debugged, and includes all the features needed.

Edited October 18, 2022 by IanD

[Antrepat]

2 hours ago, cuthound said:

The smallest (and most common are in the 10-25kVA range. Most telephone exchanges (which are rapidly being lost due to VOIP) are small rural ones.

 

I agree larger ones (up to 3MVA) and often based on ship propulsion diesel engines would be to large as they are bigger than even a full length narrowboat.

 

That's what I should do, cut off the cabin, strip out all the fittings, and just mount a 1MVA engine directly to the propeller.  Or maybe paddlewheels?

24 minutes ago, cuthound said:

 

Strange, I thought he had a 14 hp engine and wanted electric drive. 14hp is about 10kVA at unity pf.

I do have a (broken) 14hp engine at the moment and it's not really powerful enough - it is 40 years old and nothing special.  That's driving the propeller, though, whereas I'm wanting to convert it to or replace it with a generator or with an engine that can be converted to a generator later (with electric drive to the propeller).

[cuthound]

24 minutes ago, IanD said:

Being picky, about 9kVA allowing for 85% efficiency... 😉

 

If it's an AC generator (like the ex-BT ones) then something like a Victron Multiplus/Quattro is needed to charge the LFP batteries. Even the 48/10000 models can only charge at 100A maximum which is 7kW and cost getting on for £4k each, which is likely to be out of the OPs budget. For a 10kW generator he'd need the 48/15000 which costs even more... 😞

 

(or just don't use the full output of the generator)

 

Since he (unusually!) seems to want high power mainly for propulsion and battery charging not running 230Vac gear on the boat, a 48V DC generator plus a much smaller inverter would probably be the best solution, the problem is finding one (new ones are scarce and expensive) or building one (needs significant electrical system design skills).

 

Having several DC sources (generator/alternator/solar/charger) all of which need controlling presents several problems, some obvious and some not so obvious, to prevent possible battery/component damage under all circumstances -- overcharging from solar, protection against a battery disconnnect/alternator load dump, battery over/undercharging, temperature protection of battery and alternator. I know people like nicknorman are aware of all these issues and capable of designing a system to deal with them, but it's not as easy as it first appears.

 

It's why the more conventional (but expensive) route is to have a master controller which oversees everything including battery management, alternator charging, protection, MPPT control, and where an AC generator is just another input to deal with, and the core of the system is a big inverter/charger like a Victron, often with an external controller like a Cerbo. It's not cheap but it works and has been extensively debugged, and includes all the features needed.

 

As you say, no need to use the full output of the generator, just fuse the input appropriately for your chosen cable size.

 

After all you don't choose an electric vehicle charger to match the rating of the incoming mains supply of a house do you.

[IanD]

1 minute ago, cuthound said:

 

As you say, no need to use the full output of the generator, just fuse the input appropriately for your chosen cable size.

 

After all you don't choose an electric vehicle charger to match the rating of the incoming mains supply of a house do you.

 

All true. But the fact remains that the ex-BT 10kVA generators are AC, need a big/expensive inverter to charge the batteries, are physically quite large so not easy to fit into a boat -- much bigger than a compact 7kW marine generator, for example -- and will need converting to keel cooling.

 

The OPs idea of a small engine directly linked to an inline 48V alternator like the Manel ones looks likely to be a lot smaller and cheaper and more like what he wants, but presents a lot of control/protection challenges, including many that he may not have thought of... 😉

[Antrepat]

16 minutes ago, cuthound said:

 

As you say, no need to use the full output of the generator, just fuse the input appropriately for your chosen cable size.

 

After all you don't choose an electric vehicle charger to match the rating of the incoming mains supply of a house do you.

Good point, but it's more a matter of physical size than electrical capacity.

[Antrepat]

10 minutes ago, IanD said:

The OPs idea of a small engine directly linked to an inline 48V alternator like the Manel ones looks likely to be a lot smaller and cheaper and more like what he wants, but presents a lot of control/protection challenges, including many that he may not have thought of...

Hence why I come here, asking my naive, ill-informed, damn-fool questions of those who have fallen into these pits themselves...

 

Here's the latest reckoning, if anyone is interested:

 

Alternator	Sincro	E3 2-48/150	Manel	€988.20	£851.90
Engine	Kubota	BZ482	Beta		£4,000.00
Batteries	EVE	64 @ 105Ah	Fogstar		£3,806.98
BMS	REC	REC Q	Off Grid SS	$938.80	£823.51
Motor			Voltsport		£2,500.00
Misc.					£500.00
					£12,482.39

 

Misc. would include cabling, fusing, switches and breakers, battery assembly and stowage.  A power relay is included in the cost of the BMS.  Big questions remaining: electrical protection design, BMS "charge enable" output interface with engine start/stop and alternator voltage control, physical arrangement in engine bay (battery adjacent but in a separate compartment).  I haven't heard from Beta again about supplying a BZ482 without alternator so I can fit the Sincro one, and I worry that they're getting tired of my silly questions.  In the meantime I found a new Z482 for sale elsewhere and I do wonder what's involved in making it use a skin tank for cooling...

[IanD]

23 minutes ago, Antrepat said:

Hence why I come here, asking my naive, ill-informed, damn-fool questions of those who have fallen into these pits themselves...

 

Here's the latest reckoning, if anyone is interested:

 

 

Alternator	Sincro	E3 2-48/150	Manel	€988.20	£851.90
Engine	Kubota	BZ482	Beta		£4,000.00
Batteries	EVE	64 @ 105Ah	Fogstar		£3,806.98
BMS	REC	REC Q	Off Grid SS	$938.80	£823.51
Motor			Voltsport		£2,500.00
Misc.					£500.00
					£12,482.39

 

Misc. would include cabling, fusing, switches and breakers, battery assembly and stowage.  A power relay is included in the cost of the BMS.  Big questions remaining: electrical protection design, BMS "charge enable" output interface with engine start/stop and alternator voltage control, physical arrangement in engine bay (battery adjacent but in a separate compartment).  I haven't heard from Beta again about supplying a BZ482 without alternator so I can fit the Sincro one, and I worry that they're getting tired of my silly questions.  In the meantime I found a new Z482 for sale elsewhere and I do wonder what's involved in making it use a skin tank for cooling...

 

Is that "motor" price from Voltsport just the motor (which one?) or does it also include the controller? Does it also include mounting hardware? (raw motors are just cylindrical blobs)

 

IIRC their quote to me a couple of years ago was more than that, and prices have risen since then...

 

FYI if you're looking at their "narrowboat drive kit" which uses the Engiro 205W_0816 motor I wouldn't recommend this, at 48V it's 12kW/81nm/1320rpm which needs a tiny "eggbeater" prop. A much better choice is the bigger (and more expensive...) Engiro 205W_12013 which at 48V is 14kW/129nm/1080rpm which gives a much more sensible prop size... 😉

 

(I doubt that Voltsport realise this, they're not experts in boat/prop design as I found out when I talked to them)

Edited October 18, 2022 by IanD

[Antrepat]

Just now, IanD said:

Is that "motor" price from Voltsport just the motor (which one?) or does it also include the controller? Does it also include mounting hardware? (raw motors are just cylindrical blobs)

They quoted £1,935 in March 21 for a complete drive kit including ME1616 motor, Gen4 Size6 48v controller, and something called an SU280 though I don't recall what that is.  £2500 is an uplift from that.  A power handle is extra.

[IanD]

4 minutes ago, Antrepat said:

They quoted £1,935 in March 21 for a complete drive kit including ME1616 motor, Gen4 Size6 48v controller, and something called an SU280 though I don't recall what that is.  £2500 is an uplift from that.  A power handle is extra.

 

If you really want to go for a belt drive motor like this because it's cheaper then that's your decision; given the cost of the whole system, it's not a shortcut I'd take... 😉

[Antrepat]

11 minutes ago, IanD said:

 

If you really want to go for a belt drive motor like this because it's cheaper then that's your decision; given the cost of the whole system, it's not a shortcut I'd take... 😉

"I have also quoted you for a ME1616 Gen4 size6 48V kit, this will give you a direct drive."

 

Perhaps they were mistaken.

 

They quoted for their "dayboat drive system", ME1117 motor, Gen4S2 controller, £2,200; their "Small Yacht Drive Kit", ME1114 Motor, Gen4 Size4 controller, £2,400, and the ME1616, which they described as above.

 

The Direct Drive kit currently comprises:

- Engiro 205W_08016 Motor
- Gen4 Size6 48V Motor controller
- SU280 Contactor.

 

So, they changed the motor but otherwise it's the same (and that's what an SU280 is).

Edited October 18, 2022 by Antrepat

[IanD]

22 minutes ago, Antrepat said:

"I have also quoted you for a ME1616 Gen4 size6 48V kit, this will give you a direct drive."

 

Even less suitable for direct drive for a narrowboat, this is 48V/69nm/1850rpm, the prop will be a similar size (and noise) to an outboard motor... 😞

 

As so often, the devil is in the details -- the Vicprop calculator gives the following...

 

ME1616 -- 48V/69nm/1850rpm/14kW=18.7hp ==> 12.5" x 6.7" prop

205W_0816 -- 48V/81nm/1320rpm/12kW=16hp ==> 14.8" x 9" prop

205W_12013 -- 48V/129nm/1080rpm/14kW=18.7hp ==> 17.2" x 11.4" prop

 

Small high-speed props are fine for small fast boats...

 

Their "dayboat" and "small yacht" kits uses the MExxxx motors and belt drive, which allows for a bigger/slower prop -- as direct drive motors they're useless for narrowboats.

Edited October 18, 2022 by IanD

[cuthound]

4 hours ago, Antrepat said:

@cuthound: I don't suppose you have any links to post to brokers selling these?  When I looked, all I could find were clapped-out builders' generators and giant ones for backing up hospitals.

 

It is 15 years since I worked for BT but searching the web shows that Hampshire Generators often have ex-BT gennies for sale. You could contact them on 01329 722390 and see if or when they have some in stock 29722390 72239001329 722390

[Antrepat]

5 hours ago, IanD said:

 

Even less suitable for direct drive for a narrowboat, this is 48V/69nm/1850rpm, the prop will be a similar size (and noise) to an outboard motor... 😞

 

As so often, the devil is in the details -- the Vicprop calculator gives the following...

 

ME1616 -- 48V/69nm/1850rpm/14kW=18.7hp ==> 12.5" x 6.7" prop

205W_0816 -- 48V/81nm/1320rpm/12kW=16hp ==> 14.8" x 9" prop

205W_12013 -- 48V/129nm/1080rpm/14kW=18.7hp ==> 17.2" x 11.4" prop

 

Small high-speed props are fine for small fast boats...

 

Their "dayboat" and "small yacht" kits uses the MExxxx motors and belt drive, which allows for a bigger/slower prop -- as direct drive motors they're useless for narrowboats.

 

OK so which is not a silly one, then?

 

(But I don't think we should hijack this topic about 48v alternators to start discussing motors and propellers, much as I appreciate your point.  If only I'd measured my propeller and the space available for one when I had the boat out for blacking last year.  Keelblack seems to be fine so far, by the way, but that's one for yet another different topic...)

Edited October 18, 2022 by Antrepat

[Alan de Enfield]

9 hours ago, Antrepat said:

OK so which is not a silly one, then?

 

The only 'sensible one' will be the one that IanD is using.

[IanD]

10 hours ago, Antrepat said:

 

OK so which is not a silly one, then?

 

(But I don't think we should hijack this topic about 48v alternators to start discussing motors and propellers, much as I appreciate your point.  If only I'd measured my propeller and the space available for one when I had the boat out for blacking last year.  Keelblack seems to be fine so far, by the way, but that's one for yet another different topic...)

 

There are many people on the forum (including Alan, taking yet another opportunity for a personal dig instead of a sensible comment...) who deride small high-speed "egg-beater" propellers as inappropriate on canals, because they're noisy and prone to cavitation and give poor stopping power, and subscribe to the "bigger and slower is better" view -- which is correct, up to a point. In marine engineering 1000rpm is often recommended as a maximum speed for propellers in low-speed boats like trawlers and tugs (and narrowboats), it's not a hard and fast rule but is good practice.

 

I'd say the discussion is appropriate on this thread because though the OP started off just discussing 48V alternators this has now shifted to the entire proposed hybrid propulsion system including generator (bought or DIY, 48V DC or 230Vac, propulsion motor) -- and this is largely about cost, and the choice of motor has a big impact on this. In spite of being suggested as being suitable for direct drive, the cheap motors suggested from Voltsport are not a good choice for directly propelling a narrowboat (the much more expensive Engiro one is) because the torque is too low and the speed is too high, and this information -- which is not widely understood -- should be useful to both the OP and anyone else proposing to go down the same route to save money -- or they should use belt drive with its disadvantages (and the advantage of being cheaper)...

 

56 minutes ago, Alan de Enfield said:

 

The only 'sensible one' will be the one that IanD is using.

 

Given your expert knowledge about the subject, if you don't like what I suggested what electric motor would you recommend, given the power/torque/rpm/prop facts noted above? 🙂

Edited October 19, 2022 by IanD

[nicknorman]

1 hour ago, Alan de Enfield said:

 

The only 'sensible one' will be the one that IanD is using.

Well let’s be fair, IanD is a great inventor of gadgets. His latest invention is one of those burglar deterrents that, on detection of intrusion, automatically makes a loud barking sound to scare them off. He’s called it the Dog-Matic.

 

(No sulking Ian, it was a joke that I’m sure you will enjoy bouncing back to me!)

[IanD]

1 hour ago, nicknorman said:

Well let’s be fair, IanD is a great inventor of gadgets. His latest invention is one of those burglar deterrents that, on detection of intrusion, automatically makes a loud barking sound to scare them off. He’s called it the Dog-Matic.

 

(No sulking Ian, it was a joke that I’m sure you will enjoy bouncing back to me!)

 

I just get irritated when Alan keeps on making personal digs -- and I could point out that on this subject (unlike Alan...) I spent several months investigating the availability and performance of all the electric motors on the market before coming to a decision -- based on fact, not opinion... 😉

 

For anyone interested in more facts, another good marine engineering "rule-of-thumb" is that optimum propeller tip speed for a slow boat (for low noise/cavitation/good bollard pull) is about 25m/s -- smaller props will be higher than this, bigger props lower...

 

ME1616 -- 48V/69nm/1850rpm/14kW=18.7hp ==> 12.5" x 6.7" prop (31m/s tip speed)

205W_0816 -- 48V/81nm/1320rpm/12kW=16hp ==> 14.8" x 9" prop (26m/s tip speed)

205W_12013 -- 48V/129nm/1080rpm/14kW=18.7hp ==> 17.2" x 11.4" prop (25m/s tip speed)

 

P.S. If you think I'm dogmatic, try asking Alan about anchors... 🙂

Edited October 19, 2022 by IanD

[Antrepat]

@IanD @Alan de Enfield Behave!

[Jon57]

1 minute ago, Antrepat said:

@IanD @Alan de Enfield Behave!

Whose willy is bigger 🤣🤣🤣

[IanD]

5 minutes ago, Antrepat said:

@IanD @Alan de Enfield Behave!

He started it. And his mother was a hamster and his father smelt of elderberries... 😉

[Antrepat]

3 hours ago, IanD said:

I'd say the discussion is appropriate on this thread because though the OP started off just discussing 48V alternators this has now shifted to the entire proposed hybrid propulsion system including generator (bought or DIY, 48V DC or 230Vac, propulsion motor)

 

Actually I've tried to keep it on-topic and this thread is supposed to be about the generation component.  I've got a different thread for charging termination, though they are of course linked because the power generation needs to be disconnected gracefully and shut down when the charge termination parameters are fulfilled.  Mea culpa, though, because I did begin to digress into the wider system, but that was in part because of remarks about it not being possible for under £10k when I hadn't actually mentioned any specific budget.  I'm happy to shut up about the other stuff and stick to the matter of how to get an effective generator that (1) isn't £20k, (2) isn't going to knacker the engine bearings by putting a massive alternator on a belt rather than axially, and (3) is controllable in response to the measured state of the battery to allow charge termination as required by everyday practicality and the special needs of managing an LFP battery.

 

Easy-peasy 🤪

[IanD]

1 hour ago, Antrepat said:

 

Actually I've tried to keep it on-topic and this thread is supposed to be about the generation component.  I've got a different thread for charging termination, though they are of course linked because the power generation needs to be disconnected gracefully and shut down when the charge termination parameters are fulfilled.  Mea culpa, though, because I did begin to digress into the wider system, but that was in part because of remarks about it not being possible for under £10k when I hadn't actually mentioned any specific budget.  I'm happy to shut up about the other stuff and stick to the matter of how to get an effective generator that (1) isn't £20k, (2) isn't going to knacker the engine bearings by putting a massive alternator on a belt rather than axially, and (3) is controllable in response to the measured state of the battery to allow charge termination as required by everyday practicality and the special needs of managing an LFP battery.

 

Easy-peasy 🤪

 

As I'm sure you've realised, if you're going to go DIY your best bet is an axial alternator/generator -- the Manel one looks to do the job but also doesn't look possible to control externally. All PMAC motors/controllers (e.g. Engiro/Motenergy + Sevcon) can be used in regenerative mode as a generator so this might be a way around this problem, however you need something to tell the controller what to do (current/torque command) over CANbus -- a Raspberry Pi with a CANbus controller could do this, but you'd have to write all the software yourself. This could also control the BMS, but again you'd have to write the software yourself. Unless you're experienced at this it's easy to have either bugs or corner cases that the software can't cope with which could lead to damage to one or several parts of the system.

 

The problems isn't really the hardware, it's tying everything together with software and making this robust and error/idiot-proof. You'd also need a display and code to drive this to let you control the system. None of which is impossible, but neither is it easy.

 

I suspect your only way forward is to do what most people do and separate out the generator function and the BMS, and use off-the-shelf parts for both -- though a DIY generator would be a challenge in itself. Alternatively go the alternator/Wakespeed route and use a BMS which can integrate with the Wakespeed, I believe some of the available standalone BMS can do this (as can Victron gear). If you could find an axial alternator with external field control then this would do the job, but AFAIK all alternators like this are designed to spin much faster than a diesel engine via a belt drive... 😞

 

If you can arrange for 2 polyvee crankshaft pulleys then you could use 2 standard alternators on opposite sides of the crankshaft which would cancel out any lateral loads, and if the engine comes from Beta then they could presumably supply you with the alternators (ready for external control) too -- two of the Iskra 24V 100A ones in series would give you just over 5kW, or you could pay a lot more for two Balmars or similar, all controlled using a Wakespeed.

 

A Beta Greenline 16 (600cc 2-cyl Kubota) can continuously put out 12hp/9kW at 2600rpm (peak torque so also best efficiency) which is what is needed to drive the two 24V 100A Iskra alternators (see plots I posted earlier) to generate 5kW at 48V DC -- assuming Beta can fit 2 polyvee pulleys to the crank, which may not be possible. But I suspect by the time you've done this and added a Wakespeed, the cost will be similar to a Betaset 6/2 (28A/230Vac=6.5kW), and less efficient -- so more fuel used and hot-running alternators...

Edited October 19, 2022 by IanD