Another Smartgauge question.

[Graham.m]

 

 

 

I suspect Tony was referring to your post #9 as above. You clearly state your alternator produces an initial charge voltage that later drops, and also mention minimal (0.1 volt) voltage drop on cable run to batteries. This is at odds with the norm hence comments.

 

I notice the OP has now revised his findings to show a rising battery voltage under charge as one would expect.

In #9 I wrote "My alternator's initial charge voltage is in the area of 14.7 volts and drops eventually to about 14. I suspect this is a function of the regulator." ie over the charging cycle the smart regulator drops it to about 14 volts at the end of the charge, similar to a battery charger.

 

Re 0.1V I wrote "Mine is at batteries, of course, although the volt drop is less than 0.1V A to B" where does minmal come from and why is this at odds with the norm?

Yeabut you'd need a midpoint current figure to be able to estimate the shape of the curve, otherwise your method is as much guesswork as mine was!

 

As mine was

Edited December 7, 2015 by Graham.m

[Graham.m]

Rob

 

Is this the beasty ? http://sterling-power.com/products/universal-advanced-digital-alternator-regulator-pro-reg-dw-waterproof

[dmr]

I have only scan read this thread, but surely.....

most of us know that smartgage works pretty well.

Its a bit weak during charge as it can only guess at the current going in, but it still gets close.

So, if the Smartgage is giving bad readings its almost certainly because the batteries are in very poor condition where the various assumptions that it makes are no longer valid.

 

All this high initial charge voltage is very odd, bulk mode by definition means less than full voltage.

A full initial charge voltage has only one cause...a sick battery not accepting charge.

 

Nick likes to say "concave asymptotes" but now we can add "graphical numeric integration" to the list of forum impressive phrases!

 

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

[WotEver]

Nick likes to say "concave asymptotes" but now we can add "graphical numeric integration" to the list of forum impressive phrases!

 

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

 

Dave's post had my mind wandering and caused me to ponder the fact that I can still remember minus-b-plus-or-minus-the-square-root-of-b-squared-minus-4-ac-all-over-2-a when I haven't used it since A-level maths well over 40 years ago.

[Graham.m]

 

Dave's post had my mind wandering and caused me to ponder the fact that I can still remember minus-b-plus-or-minus-the-square-root-of-b-squared-minus-4-ac-all-over-2-a when I haven't used it since A-level maths well over 40 years ago.

lol Your better than me but then last time I used it was over nearly 50 years ago

[MtB]

 

Dave's post had my mind wandering and caused me to ponder the fact that I can still remember minus-b-plus-or-minus-the-square-root-of-b-squared-minus-4-ac-all-over-2-a when I haven't used it since A-level maths well over 40 years ago.

 

 

Hey I was only the other day trying to remember that. The roots of a quadratic equation IIRC.

 

I've also forgotten that really long 27 turn move needed to complete the solving of a Rubiks Cube!!

[WotEver]

 

 

Hey I was only the other day trying to remember that. The roots of a quadratic equation IIRC.

 

Yup, the solve for a quadratic.

 

What a shock to the system I had when moving from O Level Maths to A Level. In O Level quadratic equations were a subject all on their own, in A level, first lesson, they were simply a tool!

[dmr]

 

 

Hey I was only the other day trying to remember that. The roots of a quadratic equation IIRC.

 

I've also forgotten that really long 27 turn move needed to complete the solving of a Rubiks Cube!!

 

Quadratic equations are easy, numerical integration is ok, and I can cope with all that Fourier transform stuff, but the Rubik cube was totally beyond me.

If you can remember you could show me over a pint!

 

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

[by'eck]

In #9 I wrote "My alternator's initial charge voltage is in the area of 14.7 volts and drops eventually to about 14. I suspect this is a function of the regulator." ie over the charging cycle the smart regulator drops it to about 14 volts at the end of the charge, similar to a battery charger.

 

Re 0.1V I wrote "Mine is at batteries, of course, although the volt drop is less than 0.1V A to B" where does minmal come from and why is this at odds with the norm?

 

 

Ok so you have a smart multi-stage alternator regulator with float mode. That explains the lower voltage at end of charge period, although 14.1 volts seems tad high for such - would expect in the order of 13.3- 13.8v dependant on battery setting of course. The minimal volt drop you have on charge cables means you have no issues there and that alternator and battery voltage under charger are nominally the same. We are just left with the unusually high initial charge voltage as an abnormal then.

 

I suspect that its less than this at the start of a charge period or you are quoting the charge voltage of batteries near fully charged anyway. Since it would be pointless to mention voltages in the former case, I can only assume you have a very high alternator charge current v battery capacity ratio when charging discharged batteries. This relates to a large alternator and/or low battery capacity allowing plate surface charge saturation which quickly allows battery voltage to rise to the regulated limit well before full charge is reached.

 

Unless you have a really large alternator would be inclined to check out battery capacity - it may be a fraction of what you think.

[Graham.m]

 

Ok so you have a smart multi-stage alternator regulator with float mode. That explains the lower voltage at end of charge period, although 14.1 volts seems tad high for such - would expect in the order of 13.3- 13.8v dependant on battery setting of course. The minimal volt drop you have on charge cables means you have no issues there and that alternator and battery voltage under charger are nominally the same. We are just left with the unusually high initial charge voltage as an abnormal then.

 

I suspect that its less than this at the start of a charge period or you are quoting the charge voltage of batteries near fully charged anyway. Since it would be pointless to mention voltages in the former case, I can only assume you have a very high alternator charge current v battery capacity ratio when charging discharged batteries. This relates to a large alternator and/or low battery capacity allowing plate surface charge saturation which quickly allows battery voltage to rise to the regulated limit well before full charge is reached.

 

Unless you have a really large alternator would be inclined to check out battery capacity - it may be a fraction of what you think.

Think I need to lend you my glasses I did not say 14.1 I said about 14. Please define about 14, what range would that cover, also what type of batteries do I have as that is relevant to the voltages. As for the alternator it is a perfect match for my system.

 

With reference to the beginning of the sentence "charge voltage is in the area of 14.7 volts "

 

I know the capacity of my batteries is to within about 5% and they are 4 years old hence it is not design capacity but they are still healthy. I know the Ahs that come out and the Ahs that go back in.

 

Glad you agree that less than 0.1V is acceptable, I had to rewire the system to get that and the voltage when finally finished was considerably less than 0.1V. Had to make sure all the terminations mated properly and used silver soldered rather than crimped. But I am lucky enough to have the tools to do it. Shalom

Edited December 7, 2015 by Graham.m

[ROBDEN]

Morning all.

 

This mornings strange charging figures.

 

The PDAR is disconnected.

 

SG reads 12.2v. 60%.

 

Engine run at 1000 revs

 

Start. 14.05. @62amps. SG….60%

+20 minutes. 14.2 @47amps

+20 minutes. 14.25 @35amps

+20 minutes. 14.5 @10amps

+20 minutes. 14.5 @2amps SG….76%

+20 minutes. 14.5 @ jumping between 3 and 8amps. SG….80%.

 

Still running.

 

Later today I’ll see if I can remove the top from one of the sealed batteries

to check the water level.

Rob....

[Graham.m]

 

Morning all.

 

This mornings strange charging figures.

 

The PDAR is disconnected.

 

SG reads 12.2v. 60%.

 

Engine run at 1000 revs

 

Start. 14.05. @62amps. SG….60%

+20 minutes. 14.2 @47amps

+20 minutes. 14.25 @35amps

+20 minutes. 14.5 @10amps

+20 minutes. 14.5 @2amps SG….76%

+20 minutes. 14.5 @ jumping between 3 and 8amps. SG….80%.

 

Still running.

 

Later today I’ll see if I can remove the top from one of the sealed batteries

to check the water level.

Rob....

 

 

Unfortunately those are the figures I would expect for a low capacity battery.

 

Ref the last reading that looks like something on the DC boats circuits is switching on, maybe a fridge or waterpump or the like and the charger is just adjusting to the demand.

 

I think it is unlikely that you will be able to see the water level in the battery, it depends on the construction and whether they have used a gel in a surrounding envelope etc. Do be careful if you do attempt to remove the battery top, there is acid and that battery will still have a lot of energy in it if shorted etc, safety glasses and clothing please

Oh if you see this in time. Stop charging wait 30 minutes and restart the charger and see what the figures are

[ROBDEN]

 

Unfortunately those are the figures I would expect for a low capacity battery.

 

Ref the last reading that looks like something on the DC boats circuits is switching on, maybe a fridge or waterpump or the like and the charger is just adjusting to the demand.

 

I think it is unlikely that you will be able to see the water level in the battery, it depends on the construction and whether they have used a gel in a surrounding envelope etc. Do be careful if you do attempt to remove the battery top, there is acid and that battery will still have a lot of energy in it if shorted etc, safety glasses and clothing please

Oh if you see this in time. Stop charging wait 30 minutes and restart the charger and see what the figures are

Thanks for your concern Graham.

Just going to stop now.......back in 30.

 

Rob....

[ROBDEN]

Restarted engine.

 

SG...86%

14.5 @33amps. After about 5 minutes back to 14.5 @0-1amp.

 

I'd better see if I can find the batteries' invoice.

 

Rob....

[Graham.m]

Restarted engine.

 

SG...86%

14.5 @33amps. After about 5 minutes back to 14.5 @0-1amp.

 

I'd better see if I can find the batteries' invoice.

 

Rob....

 

Email from le company

 

I asked about charging voltages

 

Hi Graham,

 

Thankyou for your email.

 

A full charged battery should be reading anywhere between 12.6v - 13v.

Should be charging at around 14v - 14.5v with 11amp current.

 

Kind Regards

 

Now there are lots on here who are going to disagree with that but they are the recommendations

 

I think you will find that the sterling regulator is adjustable for battery type/voltage.

 

Ed Just a thought when did you fit the Sterling Regulator, how long a go? or did someone fit it for you?

Edited December 8, 2015 by Graham.m

[dmr]

 

Email from le company

 

I asked about charging voltages

 

Hi Graham,

 

Thankyou for your email.

 

A full charged battery should be reading anywhere between 12.6v - 13v.

Should be charging at around 14v - 14.5v with 11amp current.

 

Kind Regards

 

Now there are lots on here who are going to disagree with that but they are the recommendations

 

I think you will find that the sterling regulator is adjustable for battery type/voltage.

 

Ed Just a thought when did you fit the Sterling Regulator, how long a go? or did someone fit it for you?

 

This might sound rude but its not intended to be.....

If you want to know about battery voltages you need to speak to an engineer, not a shop assistant!

 

How often have you been to a garage and given your flat battery to the "battery expert" who puts a drop tester across it and says "its dead you need a new one" ?

 

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

[MtB]

 

This might sound rude but its not intended to be.....

If you want to know about battery voltages you need to speak to an engineer, not a shop assistant!

 

How often have you been to a garage and given your flat battery to the "battery expert" who puts a drop tester across it and says "its dead you need a new one" ?

 

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

 

 

And worse, when the new battery goes flat too, they realise they need to tighten the fan belt?

[Graham.m]

 

This might sound rude but its not intended to be.....

If you want to know about battery voltages you need to speak to an engineer, not a shop assistant!

 

How often have you been to a garage and given your flat battery to the "battery expert" who puts a drop tester across it and says "its dead you need a new one" ?

 

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

 

As the information ties up with other knowledge I have I am quite happy with it. I asked for it from the company for Rob's sake so that he is not having to believe forum experts

 

Also I have an educated guess as to what caused the problems, but waiting for Rob to confirm something

[dmr]

 

As the information ties up with other knowledge I have I am quite happy with it. I asked for it from the company for Rob's sake so that he is not having to believe forum experts

 

Also I have an educated guess as to what caused the problems, but waiting for Rob to confirm something

 

Hang on a bit

Fully charged battery voltage beetween "12.6 and 13"? with goal posts that wide you can't miss!

and you were saying the smartgage is no good because it wont do 0.05% accuracy!.

 

Lets get back to basics, (who needs instruments anyway)

Lights in boat on Battery fully charged

Lights dim and warning buzzers sounding Battery partly charged

No lights all Battery needs charging

 

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

[Graham.m]

 

Hang on a bit

Fully charged battery voltage beetween "12.6 and 13"? with goal posts that wide you can't miss!

and you were saying the smartgage is no good because it wont do 0.05% accuracy!.

 

Lets get back to basics, (who needs instruments anyway)

Lights in boat on Battery fully charged

Lights dim and warning buzzers sounding Battery partly charged

No lights all Battery needs charging

 

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

Oh dear oh dear

[bizzard]

With nothing switched on at all a good battery fully charged should hold at 12.9 to 13v for quite some time.

[Paul C]

He's got a point though - the ranges 12.6-13V and 14.0-14.5V are fairly wide. You could have guessed at those for pretty much any battery - not the precision of information you'd expect for that specific battery, from the battery manufacturer (unless they also qualified those ranges).

[Graham.m]

He's got a point though - the ranges 12.6-13V and 14.0-14.5V are fairly wide. You could have guessed at those for pretty much any battery - not the precision of information you'd expect for that specific battery, from the battery manufacturer (unless they also qualified those ranges).

 

I am only interested in the charging voltage, surely the SG will do the rest

[Paul C]

 

I am only interested in the charging voltage, surely the SG will do the rest

 

Which one - 14V or 14.5V?

[Graham.m]

 

Which one - 14V or 14.5V?

Personally I would use 14,4v