Stephanie should know better

[Mike Adams]

I have never felt the need for RCR but I would suggest for most boaters without a strong engineering background they would be good value for money. I think that they would offer a better service than most coastal boatyards due to their familiarisation with canal boats. You come across so many boats in such a nightmare electrical and mechanical condition I for one wouldn't want their job. Maybe they are the ones who call them out? The business probably only works because a lot of people join but don't claim.

[cuthound]

7 hours ago, frangar said:

My thoughts exactly! Just because you have a bit of paper doesn’t meant you know what you are doing! 

 

In my last job the designs for the data centre power and cooling systems were subcontracted out to consultants.

 

They always used newly graduated engineers. Having been at the sharp end of most aspects of critical power for over 40 years, one of my responsibilities was to critique and approve their designs. The ones who would go far took the criticism as a learning point, the others didnt last long...

 

Although I have worked on both AC and DC systems from 5 to 66,000 volts, I feel that after 6 years of boat ownership I am just approaching the end my apprenticeship on boat electrics! ?

Edited June 15, 2020 by cuthound
To add the last paragraph

[WotEver]

4 hours ago, Mike Adams said:

... she did say flat rather than 50% charged and if they the batteries were that low I think that 3 to 5hours with the alternator running fast would put most of the capacity back in the batteries if they were in good condition.

Indeed, she did say flat as opposed to 50%, so her error is even more extreme.
 

In 3-5 hours a 440Ah bank being charged by a 70A alternator will (if the engine is running fast enough) have just about got to about 50-60% SoC from flat, and the alternator will be red hot. Another dozen or so hours would be required to fully recharge them. 

[ditchcrawler]

1 hour ago, cuthound said:

 

In my last job the designs for the data centre power and cooling systems were subcontracted out to consultants. 

Consultants get very pee'd off when you refer to them as contractors.

[Murflynn]

contractors have a bad reputation in many business environments, especially individual agency-recruited contract staff.  

in the oil and gas business the oil company staff resent their presence - 'overpaid and irresponsible' ...............  then the night of the long knives inevitably happens and the staff numbers are cut by half  ....................  suddenly all the redundant staff want to be re-hired as contractors.   

[cuthound]

13 minutes ago, ditchcrawler said:

Consultants get very pee'd off when you refer to them as contractors.

 

True, but that's what they were.

 

The company I worked for contracted to fit-out data centres,  employed about 2% of its own staff directly (I was one), the rest of its employees were individuals or companies subcontracted to them, including project managers, package managers, technical managers, commissioning managers, contract managers, draughtsmen, tradesmen, labourers, delapidation surveyors, specialist suppliers and consultants.

 

As they sought to increase profitability they brought more and more of these services in house giving them to the handful of people they employed directly in addition to their normal work.

[Machpoint005]

7 hours ago, Mike Adams said:

she did say flat rather than 50% charged and if they the batteries were that low I think that 3 to 5hours with the alternator running fast would put most of the capacity back in the batteries if they were in good condition.

 

You can run the engine as long as you like, but it will do you no good if the battery is f*cked.

 

 

Real world experience.

 

[Mike Adams]

2 hours ago, WotEver said:

In 3-5 hours a 440Ah bank being charged by a 70A alternator will (if the engine is running fast enough) have just about got to about 50-60% SoC from flat, and the alternator will be red hot. Another dozen or so hours would be required to fully recharge them. 

I don't think you would actually get much more than say 350Ah useful capacity out of a 440Ah battery bank. When flat at at say 10.5v they probably have 10-15% capacity left according to the manufacturers and most alternators will start to cut out at about 14.4v so it would be painfully slow to get the last bit of charge into the battery with a simple voltage controlled alternator so running for another dozen hours would be a very inefficient way to operate. A 70Ah alternator is not really suitable for that size battery if you are going to use it to capacity. Most are designed for automotive type use where the max current is only supplied after  a large starting discharge.

 

28 minutes ago, Machpoint005 said:

You can run the engine as long as you like, but it will do you no good if the battery is f*cked.

 

A f*cked battery is as much use as a chocolate teapot. Weigh it in and get a new one.

[Arthur Marshall]

32 minutes ago, Machpoint005 said:

 

You can run the engine as long as you like, but it will do you no good if the battery is f*cked.

 

 

Real world experience.

 

As a cheerful electrical ignoramus when I moved onto my boat, I happily ran the engine for an hour every two or three days. That gave me enough oomph to get lights through an evening and even let me watch an hour of TV.  When the lights wouldn't any more I went to bed and ran the engine next day. For an hour. And, to be honest, I don't think the battery died any quicker than subsequent ones when I was cruising.

It may be different now, with people having six batteries and a pile of electronics, but was perfectly manageable then, and, on my tub, still seems to be.

[David Mack]

12 hours ago, Tracy D'arth said:

I think I would have more faith in an RAC man than a lot of the guys RCR use.

Some years ago I had to call out the RAC in the middle of the night, to deal with a WRG diesel land rover which wouldn't start. We suspected it just needed the fuel system bleeding, but we didn't have any tools with us. The mechanic who turned up from a local garage on behalf of the RAC hadn't a clue about diesel engines, and didn't know anything about bleeding the system. In the end we had to borrow his tools and do the job ourselves while he waited! Once bled it started first time.

[Arthur Marshall]

17 minutes ago, David Mack said:

Some years ago I had to call out the RAC in the middle of the night, to deal with a WRG diesel land rover which wouldn't start. We suspected it just needed the fuel system bleeding, but we didn't have any tools with us. The mechanic who turned up from a local garage on behalf of the RAC hadn't a clue about diesel engines, and didn't know anything about bleeding the system. In the end we had to borrow his tools and do the job ourselves while he waited! Once bled it started first time.

Like when I had gearbox trouble and the guy RCR sent just said he knew nowt about Listers and refused to even take the top off. I showed him the manual, told him what needed doing, and he just shrugged and buggered off. RCR then sent my usual guy from halfway across the country on a consultancy basis and it took him longer to take the cover off than to fix the problem. I wouldn't do it, being terminally cack-handed.

But I have also had great service from them, as well as two grand towards repairs.

[smiler]

On 15/06/2020 at 16:41, WotEver said:

Indeed, she did say flat as opposed to 50%, so her error is even more extreme.
 

In 3-5 hours a 440Ah bank being charged by a 70A alternator will (if the engine is running fast enough) have just about got to about 50-60% SoC from flat, and the alternator will be red hot. Another dozen or so hours would be required to fully recharge them. 

Shhhh......

Don't tell everybody or there will be even more numpties running their engines every night until the early hours ???

[tree monkey]

On 15/06/2020 at 17:27, Murflynn said:

contractors have a bad reputation in many business environments, especially individual agency-recruited contract staff.  

in the oil and gas business the oil company staff resent their presence - 'overpaid and irresponsible' ...............  then the night of the long knives inevitably happens and the staff numbers are cut by half  ....................  suddenly all the redundant staff want to be re-hired as contractors.   

I worked in a few roles as a contractor for none arb company's since I came off the tools and I was a bit shocked at the attitude I got from some of the direct staff.

Ok yes, I did have a company van for private use and maybe earned a touch more weekly but no early retirement on index linked pay, a lot less generous sick pay and holiday entitlements, no double bubble for Sunday plus day off in lieu, no out of hours bonus.

That van really upset some people

[Sir Nibble]

On 15/06/2020 at 18:38, Mike Adams said:

 Most are designed for automotive type use where the max current is only supplied after  a large starting discharge.

 

 

This is absolutely not the case. An automotive alternator is not sized according to what's needed to charge the battery, it's specified to cover the electrical loads. Cold wet night,  Fuel pump, engine ignition and electronics, cooling fans, full lighting load, wipers, heater, heated windows, mirrors seats. Modern cars have a huge electrical demand. When this is met an extra 5A for the battery and there's your charging system specification. A vehicle alternator can easily run close to full output for hours at a time. it can easily take 20A just to keep the engine running, another 20 for headlamps, it all mounts up.

[Mike Adams]

16 minutes ago, Sir Nibble said:

This is absolutely not the case. An automotive alternator is not sized according to what's needed to charge the battery, it's specified to cover the electrical loads. Cold wet night,  Fuel pump, engine ignition and electronics, cooling fans, full lighting load, wipers, heater, heated windows, mirrors seats. Modern cars have a huge electrical demand. When this is met an extra 5A for the battery and there's your charging system specification. A vehicle alternator can easily run close to full output for hours at a time. it can easily take 20A just to keep the engine running, another 20 for headlamps, it all mounts up.

Most modern narrowboat engines are marinised plant and industrial engines which would typically not have those loads

[Sir Nibble]

12 minutes ago, Mike Adams said:

Most modern narrowboat engines are marinised plant and industrial engines which would typically not have those loads

They wouldn't normally have the 40A alternator sized for a mini digger either. The alternators used are as you say, automotive units for the most part and intended for automotive loads. The issue with boat installations is fresh air for cooling but the alternator can't tell the difference between 100A for a narrowboat battery bank and 100A for the whistles and bells on a top of the range car. I don't think I've ever seen a marine alternator that's not at least based on an automotive unit.

Edit. Yes I have! The dreadful little 35A SEV brushless jobbies, now long defunct.

Edited June 16, 2020 by Sir Nibble

[Ex Brummie]

I joined R.C.R. 3 years ago, after 30 years of boating without any 'support'.  The only time I've had bother that could have been difficult was when my starter motor went kaput. Fortunately I was in Lincoln, and managed to get on a vacant Pool mooring and get to the local Lucas merchant. (My starter on a 4108M is far from the standard unit on road vehicles).

I can manage lots of jobs, and carry spares, but if my starter should fail again, or the drive plate, and in the middle of nowhere, then I have a phone contact to hand, and insurance to cover the cost of spares and transport home, with the boat to a local repairer. It seems a reasonable bet for me. In comparison to road recovery, it seems to be on a par.

RCR only cover engine faults, your domestic services are not covered, but at least you are still able to cruise somewhere. It's a little petty to criticise the use of fan belt when it is a universally understood term for a common item.

[Mike Adams]

Of course the loads are different in each case. The 'car' load presents an ohmic load while the battery as it charges presents a ever higher EMF as it starts to charge that is why it is so difficult to reach a high state of charge quickly. The voltage/current output curve for the alternator will probably offer is rated output at say 13v but will fall off until it cuts out at say 14.4v. My boat has a 120A car alternator and it never gets the domestic batteries to the charge level that the solar panel does if that  left on for a few days yet if the batteries are very low the alternator soon brings them up to a reasonable charge level. The way to go would be with an intelligent controller but then you run in to problems of over heating and I think AGM batteries are prone to that having crossed the channel once flat out and ended up with two very cooked batteries.

[Sir Nibble]

36 minutes ago, Mike Adams said:

Of course the loads are different in each case. The 'car' load presents an ohmic load while the battery as it charges presents a ever higher EMF as it starts to charge that is why it is so difficult to reach a high state of charge quickly. The voltage/current output curve for the alternator will probably offer is rated output at say 13v but will fall off until it cuts out at say 14.4v. My boat has a 120A car alternator and it never gets the domestic batteries to the charge level that the solar panel does if that  left on for a few days yet if the batteries are very low the alternator soon brings them up to a reasonable charge level. The way to go would be with an intelligent controller but then you run in to problems of over heating and I think AGM batteries are prone to that having crossed the channel once flat out and ended up with two very cooked batteries.

absolutely. It was only this......

On 15/06/2020 at 18:38, Mike Adams said:

Most are designed for automotive type use where the max current is only supplied after  a large starting discharge.

 

 

Which I took issue with.

Indeed, for the reasons you describe a boat alternator has an easier time with the battery presenting a higher and higher back emf to the alternator whereas the load from a motor vehicle system remains as great after 200 miles as it did at startup. If it was only "a large starting discharge" to be concerned with then a C39 dynamo would be overkill. I think the alternator would get the batteries to just as high a state of charge if you left that on for a few days too! I can only speak from my own training and experience and from time to time I come across things like "An automotive alternator isn't designed for high output for long periods" or "marine alternators are derated for reliability" which in my experience are simply untrue.

[Mike Adams]

9 minutes ago, Sir Nibble said:

Most are designed for automotive type use where the max current is only supplied after  a large starting discharge.

I see where there was a misunderstanding. What I meant to say was that the max current is only supplied to the battery after a large starting discharge when the EMF is low.

[Sir Nibble]

18 minutes ago, Mike Adams said:

I see where there was a misunderstanding. What I meant to say was that the max current is only supplied to the battery after a large starting discharge when the EMF is low.

Gotcha.?

It's all about ampere hours and although a lot of people have made a lot of money convincing folks otherwise, you soon come to a point where amps stop being the answer and you have to put in the hours.

[WotEver]

1 hour ago, Mike Adams said:

I see where there was a misunderstanding. What I meant to say was that the max current is only supplied to the battery after a large starting discharge when the EMF is low.

Or when the domestic batteries are 'flat' to bring the thread back onto topic.  And as per the whole point of this thread, a 'flat' 440Ah LA bank will not be fully charged in 4-5 hours with a 70A alternator.