Improving BMC engine charging

[Tony Brooks]

The photo seem to show one of the horrible pressed tin alternator pulleys.  If so I think you can get a smaller cast one but it would need a notched/cogged belt.

[dmr]

3 hours ago, Poppin said:

Thanks for all the replies in such a short timeframe!

 

I have been on the phone with Adverc and they've sent me over some documentation. Seems they do a reasonable discount if you purchase both a 90A alternator and Adverc controller. Just trying to absorb all the info in what they've sent. 

 

To quickly answer some of your questions: 

 

I base the SOC on the Smart bank advance system I have installed. 

 

Hopefully this picture will give you an idea of pulley ratio (I KNOW THE POWDER RESIDUE IS FROM THE BELT, this is an old pic)

 

Looks like you might be pretty much stuck with that pulley ratio unless you want to spend a lot of money.

 

There is a lot of "wisdom" on this forum, partly derived from the Smartgage website, that says that its not worth fitting an Adverc. My own experience (backed up with some knowledge of electricity) is that the Adverc usually gives a huge improvement in the charging current. However because of this it will make the alternator work quite a lot harder so a good alternator is required. I suspect Adverc only sell suitable alternators. 90 amps is about the maximum for your single belt arrangement, and as said, a good quality notched belt would be a good idea.

 

If you want even more current then fitting a second alternator might be the best approach but this could be quite expensive.

 

................Dave

[Tony Brooks]

4 minutes ago, dmr said:

Looks like you might be pretty much stuck with that pulley ratio unless you want to spend a lot of money.

 

There is a lot of "wisdom" on this forum, partly derived from the Smartgage website, that says that its not worth fitting an Adverc. My own experience (backed up with some knowledge of electricity) is that the Adverc usually gives a huge improvement in the charging current. However because of this it will make the alternator work quite a lot harder so a good alternator is required. I suspect Adverc only sell suitable alternators. 90 amps is about the maximum for your single belt arrangement, and as said, a good quality notched belt would be a good idea.

 

If you want even more current then fitting a second alternator might be the best approach but this could be quite expensive.

 

................Dave

 

It all depends upon what voltage the Adverc is set to and the alternator regulator voltage. When I bought an Adverc plus "ready wired" Paris Rhone regulator I later found they supplied a 13.8 ish regulator with the Adverc set to 14.2V. This was no improvement over the battery sensed 14.4 regulator that was already fitted. It also depends upon battery type. If the OP has open cell lead calcium batteries then setting the Adverc voltage to about 14.7 is likely to improve charging. An Adverc will also improve charging if there are wiring shortcomings on a machine sensed alternator but is likely to be of marginal or no benefit with a 14.5 V plus regulated voltage.

 

At least Advercs can't go into float too early like a certain other battery charging enhancer.

[Tacet]

4 hours ago, Poppin said:

 

 

4 hours ago, philjw said:

How would you calculate the pully ratio when the water pump is also driven by the crankshaft pully? Is it simply ignored?

 

4 hours ago, Mike the Boilerman said:

 

Yes. 

 

Unless the alternator was being drive by  the outboard water pump pulley.

 

Which it isn't

[MtB]

31 minutes ago, Tacet said:

 

 

Unless the alternator was being drive by  the outboard water pump pulley.

 

Which it isn't

 

Disagree. You measure the diameter of the pulley actually doing the driving. So if the outboard pulley was driving the alternator you STILL ignore the water pump drive!

[dmr]

1 hour ago, Tony Brooks said:

 

It all depends upon what voltage the Adverc is set to and the alternator regulator voltage. When I bought an Adverc plus "ready wired" Paris Rhone regulator I later found they supplied a 13.8 ish regulator with the Adverc set to 14.2V. This was no improvement over the battery sensed 14.4 regulator that was already fitted. It also depends upon battery type. If the OP has open cell lead calcium batteries then setting the Adverc voltage to about 14.7 is likely to improve charging. An Adverc will also improve charging if there are wiring shortcomings on a machine sensed alternator but is likely to be of marginal or no benefit with a 14.5 V plus regulated voltage.

 

At least Advercs can't go into float too early like a certain other battery charging enhancer.

 

The unanticipated factor in my case was that some alternators have a very "soft" or low loop gain regulator. This was the case with both of the alternators that I have used, especially the Iskra/Letrika 100amp unit.  We might expect the alternator to run flat out in bulk mode then to switch to absorption mode (when the regulator kicks in). What actually happens is that the regulator starts to back off the current long before the regulated voltage is reached. In fact the current started to reduce when the engine had only run for a few minutes. This might be in part why the OP sees such low currents. The Adverc overcomes this.

 

I also suspect that the Adverc cycling method probably has some advantages, it gives the benefit a high charge voltage without too much water loss or battery stress, which as you say is a better approach than including a float mode.

 

A possible disadvantage of the Adverc is that I recently developed a bad connection on the main charge lead and did not notice this because the Adverc just increased the charge voltage to maintain the expected charge current. When I did eventually spot it there was evidence of things getting very hot ?.  A check on alternator voltage is now part of my annual maintenance!

 

..........Dave

[WotEver]

17 minutes ago, dmr said:

The unanticipated factor in my case was that some alternators have a very "soft" or low loop gain regulator.

I wonder if this is intentional in order to reduce the load on the alternator. 

 

[dmr]

11 minutes ago, WotEver said:

I wonder if this is intentional in order to reduce the load on the alternator. 

 

Selling a 100amp alternator with a regulator designed to limits its output to 50 amps most of the time would be a bit underhand ?.

 

However without the Adverc the alternators runs nicely warm, with the Adverc it runs scarily hot!

 

..............Dave

[WotEver]

1 minute ago, dmr said:

Selling a 100amp alternator with a regulator designed to limits its output to 50 amps most of the time would be a bit underhand ?.

 

However without the Adverc the alternators runs nicely warm, with the Adverc it runs scarily hot!

 

..............Dave

Does the Adverc have a temp sensor for the alternator?

[Tacet]

1 hour ago, Tacet said:

 

 

Unless the alternator was being driven by  the outboard water pump pulley.

 

Which it isn't

 

37 minutes ago, Mike the Boilerman said:

 

Disagree. You measure the diameter of the pulley actually doing the driving. So if the outboard pulley was driving the alternator you STILL ignore the water pump drive!

If it had two belts (which it doesn't) such that the inboard pulley of the water pump was driven by the crankshaft (which it is) and the outboard water pump pulley was driving the alternator (which it isn't) ...............

[cereal tiller]

17 minutes ago, WotEver said:

Does the Adverc have a temp sensor for the alternator?

The Sterling ones do................Easy to strap on the Stator with a Hose Clip.

Edited November 21, 2018 by cereal tiller

[MtB]

12 minutes ago, Tacet said:

 

If it had two belts (which it doesn't) such that the inboard pulley of the water pump was driven by the crankshaft (which it is) and the outboard water pump pulley was driving the alternator (which it isn't) ...............

 

Yes, and?

 

Ignore the one driving the water pump, like I keep saying!

 

[dmr]

30 minutes ago, WotEver said:

Does the Adverc have a temp sensor for the alternator?

No.  The Adverc is quite a dated design and has very limited safety checks. Its all done in analog and discrete logic chips. The Sterling looks to be a processor based device and has all the bells and whistles, but the Adverc has the better basic charging strategy and is very well made. The Adverc could really do with an update and some of its logic moving into software but sadly Adverc are not really interested, they want to just keep selling the existing device with no further development. I guess their argument is that it still does its job pretty well.

 

.................Dave

 

[Tacet]

24 minutes ago, Mike the Boilerman said:

 

Yes, and?

 

Ignore the one driving the water pump, like I keep saying!

 

Err (not sounding so sure now)  - wouldn't that change the effective ratio between the crankshaft and alternator pulleys?  The linear speed of the two belts would differ due to the varying diameters of the stepped pulleys on the water pump operating as a reduction gear.

 

 

  

[cereal tiller]

Just now, Tacet said:

Err (not sounding so sure now)  - wouldn't that change the effective ratio between the crankshaft and alternator pulleys?  The linear speed of the two belts would differ due to the varying diameters of the stepped pulleys on the water pump operating as a reduction gear.

 

 

  

The Crankshaft Pulley is the DRIVING one and the Alternator Pulley is the DRIVEN one.those two alone determine the Ratio. any other that the Belt runs around are immaterial.

[Slim]

7 hours ago, Poppin said:

Thanks for all the replies in such a short timeframe!

 

I have been on the phone with Adverc and they've sent me over some documentation. Seems they do a reasonable discount if you purchase both a 90A alternator and Adverc controller. Just trying to absorb all the info in what they've sent. 

 

To quickly answer some of your questions: 

 

I base the SOC on the Smart bank advance system I have installed. 

 

Hopefully this picture will give you an idea of pulley ratio (I KNOW THE POWDER RESIDUE IS FROM THE BELT, this is an old pic)

I've got a BMC 1.8 with an A127 (70a) alternator and an Adverc and I get a significantly higher charge rate than you quote. To be honest I can't recall figures. I also have the smallest alternator pulley I could source. The whole system is some years old now and originally I had 2 x 70 a alternators. When the mounting bracket failed on the 2nd alternator failed I ditched it with little or no adverse effect. The best improvement I achieved was when I tweeked the Adverc to get 14.8 v output.

 

and it's not made by Sterling

Edited November 21, 2018 by Slim
additional point

[WotEver]

2 hours ago, Mike the Boilerman said:

 

Disagree. You measure the diameter of the pulley actually doing the driving. So if the outboard pulley was driving the alternator you STILL ignore the water pump drive!

Nahhh... you’re wrong. 

 

If the crank drives the water pump at 2:1 (for instance), and the water pump drives the alternator at 2:1 then the alternator is driven at 4:1 regardless of the ratio between the crank and alternator pulleys. Why do you think that pillar drills have idler pulleys at different sizes between the motor and the quill?

1 hour ago, cereal tiller said:

The Crankshaft Pulley is the DRIVING one and the Alternator Pulley is the DRIVEN one.those two alone determine the Ratio. any other that the Belt runs around are immaterial.

With only one belt, yes. But the discussion was about the alternator being fed from the outside pulley on the water pump by a second belt. 

[cereal tiller]

2 minutes ago, WotEver said:

Nahhh... you’re wrong. 

 

If the crank drives the water pump at 2:1 (for instance), and the water pump drives the alternator at 2:1 then the alternator is driven at 4:1 regardless of the ratio between the crank and alternator pulleys. Why do you think that pillar drills have idler pulleys at different sizes between the motor and the quill?

With only one belt, yes. But the discussion was about the alternator being fed from the outside pulley on the water pump by a second belt. 

Did not read that bit....will read it now and try hardest not to diss it.

[rusty69]

2 minutes ago, cereal tiller said:

Did not read that bit....will read it now and try hardest not to diss it.

Tis ok CT its a Diss-cussion forum.

[MtB]

5 minutes ago, WotEver said:

With only one belt, yes. But the discussion was about the alternator being fed from the outside pulley on the water pump by a second belt. 

 

Like CT, I missed that bit. I thought the photo was of a twin groove crankshaft pulley.

Just now, rusty69 said:

Tis ok CT its a Diss-cussion forum.

 

For dissing and cussing?

3 hours ago, Tacet said:

Unless the alternator was being drive by  the outboard water pump pulley.

 

Ah now I see what you mean. 

 

Apologies for being snippy !

[Sir Nibble]

It amazes me how much crap is still talked about alternators.

[Alan de Enfield]

1 minute ago, Sir Nibble said:

It amazes me how much crap is still talked about alternators.

As 'they' say "a little knowledge is a dangerous thing" (and I'm as guilty as the next man).

 

May I suggest that as you have a good knowledge / experience of these devices you could write an actual 'guidance to alternators' thread which could even be pinned as a reference document and would remove all the 'crap talked about alternators'.

 

I would welcome it, and I'm sure many others would as well.

[Tony Brooks]

7 minutes ago, Alan de Enfield said:

As 'they' say "a little knowledge is a dangerous thing" (and I'm as guilty as the next man).

 

May I suggest that as you have a good knowledge / experience of these devices you could write an actual 'guidance to alternators' thread which could even be pinned as a reference document and would remove all the 'crap talked about alternators'.

 

I would welcome it, and I'm sure many others would as well.

Well as a certain very vocal member is adamant that alternators can't regulate for current there may not be much point.

 

Unless the designers have fouled up then an alternator should not be able to burn itself out because during the first stage of charging where the batteries are demanding more current than the alternator can deliver the alternator design reduces the current so the V x A always equals the rated alternator output. It is us that talk about so and so amp alternators when we should be saying Watts. This holds true at whatever charging voltage.

 

If an alternator is designed to no fail during that first stage than it should also be fine, although hot, once that stage has passed even though the charging voltage may be elevated, its is still V XA = W.

 

Think about the alternator load on a car with all the electrical heated features running, powerful lights, blower motors flat out and electric power steering. That's a lot of amps ignoring the battery demand yet the alternator copes.

 

I think there may be an issue if the alternator is not driven fast enough for the fan to produce sufficient air flow for cooling but that comes back to what is in effect a designer (of the installation) foul up.

[dmr]

1 hour ago, Tony Brooks said:

Well as a certain very vocal member is adamant that alternators can't regulate for current there may not be much point.

 

Unless the designers have fouled up then an alternator should not be able to burn itself out because during the first stage of charging where the batteries are demanding more current than the alternator can deliver the alternator design reduces the current so the V x A always equals the rated alternator output. It is us that talk about so and so amp alternators when we should be saying Watts. This holds true at whatever charging voltage.

 

If an alternator is designed to no fail during that first stage than it should also be fine, although hot, once that stage has passed even though the charging voltage may be elevated, its is still V XA = W.

 

Think about the alternator load on a car with all the electrical heated features running, powerful lights, blower motors flat out and electric power steering. That's a lot of amps ignoring the battery demand yet the alternator copes.

 

I think there may be an issue if the alternator is not driven fast enough for the fan to produce sufficient air flow for cooling but that comes back to what is in effect a designer (of the installation) foul up.

But Tony, if an alternator can't over heat when charging a big bank of discharged batteries why do the likes of Sterling and Balmar feel a need to include temperature sensors on their controllers?

 

Any alternator, marine or automotive, will spend almost all of its life running at below its rated speed and so have some reduction in airflow, its not really a design failure, its a fact of what narrowboat engines have to do.

 

I know the maximum permitted winding temperature for my alternator and what temperature the windings are running at.

 

A lot of design effort goes into automotive alternators, its a big big issue, and some vehicles fit large frame alternators, on boats we mostly use the smaller frame alternators and drive them to their limit.

 

...............Dave.

[alan_fincher]

2 hours ago, Sir Nibble said:

It amazes me how much crap is still talked about alternators.

It would be genuinely interested to know which bits in this thread you consider to be talking the most crap.

If I'm guilty of talking any of it, I would not be in the east offended to have it publicly pointed out.

I'm sure most of us are only keen to learn, rather than to hang on to beliefs that may actually be wrong.