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Old 05-09-2011, 15:42   #31
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Re: 14.6 V Bulk 13.6 Float so what charge rate?

Quote:
Originally Posted by wolfaroo View Post
Thanks for clearing that up. I assumed the 'constant voltage' stage, which kicks in when the batteries reach a preset voltage according to the manual, could be used as a float stage. I guess it can but would render the absorbtion stage ineffective too with the voltage set so low. In any case, their wording is highly misleading!:

" e Solar Boost 2000E provides a precision Multi-stage Pulse Width
Modulation (PWM) charge control system to ensure the battery is
properly and fully charged, resulting in enhanced
battery performance with less battery maintenance. "
Yes that’s correct
I agree the wording is very misleading , your quote says it all, they claim multi state charging and enhanced battery performance, with just one voltage point for normal use.
It is a shame when for a very small extra cost , by adding a float stage, they could have produced a much better regulator.
Its particularly annoying that they disguise the deficiency with marketing hype. Rant over.
.
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Old 05-09-2011, 16:12   #32
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

I think they are accomplishing with the PWM system what other chargers accomplish with a voltage setting. They just average it out by varying the width of the pulse.
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Old 05-09-2011, 17:04   #33
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

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Originally Posted by DeepFrz View Post
I think they are accomplishing with the PWM system what other chargers accomplish with a voltage setting. They just average it out by varying the width of the pulse.
All solar regulators, other than the very cheapest, use PWM. PWM is a means of switching the solar panels off and on very rapidly to maintain the voltage required.
For the best charging of lead acid batteries the charger needs to keep the voltage at several levels. When the battery is charged the voltage needs to be reduced to a float level. This is done by altering the PWM cycle.
Some regulators only have one voltage, which compromises the ability to charge the batteries effectively. This is the problem with the 2000E.
Even regulators that have only one level , like the 2000E,generally employ PWM. Some very cheap regulators employ a slow switching of voltage, but these are unlikely to be seen in even low end regulators for boat applications
Almost every solar regulator suitable for a boat solar panel will be PWM
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Old 12-09-2011, 07:11   #34
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

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Originally Posted by noelex 77 View Post
All solar regulators, other than the very cheapest, use PWM. PWM is a means of switching the solar panels off and on very rapidly to maintain the voltage required.
For the best charging of lead acid batteries the charger needs to keep the voltage at several levels. When the battery is charged the voltage needs to be reduced to a float level. This is done by altering the PWM cycle.
Some regulators only have one voltage, which compromises the ability to charge the batteries effectively. This is the problem with the 2000E.
Even regulators that have only one level , like the 2000E,generally employ PWM. Some very cheap regulators employ a slow switching of voltage, but these are unlikely to be seen in even low end regulators for boat applications
Almost every solar regulator suitable for a boat solar panel will be PWM
Uh...I don't think the Genasun MPPT are PWM.
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Old 12-09-2011, 11:10   #35
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

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Originally Posted by OceanPlanet View Post
Uh...I don't think the Genasun MPPT are PWM.
Genasun have got some very useful charge controllers for boats.

There are really only 3 common ways to reduce the panel output
Switch it off and on
Switch it off and on very rapidly . This is PWM.
Bypass the power to a dump resistor.

The dump resistor requires a lot of heat sinking which the Genasuns do not have. That leaves the first and second option. PWM is far superior to much slower switching.

There manuals are very short on technical details , but PWM is the way all similar regulators function. There are other technical possibilities that could be used and Gensun an are innovative company
If Gensun do not use PWM how is the regulation done?
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Old 12-09-2011, 18:31   #36
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Quote:
Originally Posted by noelex 77
Genasun have got some very useful charge controllers for boats.

There are really only 3 common ways to reduce the panel output
Switch it off and on
Switch it off and on very rapidly . This is PWM.
Bypass the power to a dump resistor.

The dump resistor requires a lot of heat sinking which the Genasuns do not have. That leaves the first and second option. PWM is far superior to much slower switching.

There manuals are very short on technical details , but PWM is the way all similar regulators function. There are other technical possibilities that could be used and Gensun an are innovative company
If Gensun do not use PWM how is the regulation done?
Let's clear up some stuff here. Solar controllers are PWM regulators. That does not mean that they (a) charge the battery using a PWM or pulse output. Nor (b) does it mean that it regulates by switching tbs panels " on and off".

The pwm solar regulator is a normal buck regulator. This chops up the incoming DC from the panel feeds it to an inductor, uses a voltage error ( or current error) feedback loop and controls the output voltage by varying the PWM duty cycle. The resulting output waveform is filtered to produce pure DC ( with a small switching ripple)

This method is very common in electronic power supplies. It's more efficient ( ie less heat loss) then series pass or shunt regulation

There's never any need to switch the panel on and off ( though some crude regulators did that) in a PWM buck regulator reducing output current effectively causes the input impedance to rise. Hence the panel only supplies what the load needs. This makes buck regulation efficient.

In series pass a lot of heat is generated in the resistance of the series pass regulation penance. In shunt regulation this is improved but at high levels of regulation similar heat losses occur in the shunt resistor. ( or the active shunt semiconductor)

MPPT controllers typically use PWM buck regulators as it makes it easy to employ the "perturbate and measure " method of determining the Mppt of the panel. By adjusting the PWM the input impedance changes and hence the voltage and current point of the panel. By measuring the output current you can determine if that combination ( ie watts) is better then the previous operating point. If it is keep making the changes in that direction until the watt output falls. If not then make the impedance change in the opposite direction.

Mppt doesn't have to use PWM switching technology but it's the simplest for it to xo so.

Dave
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Old 13-09-2011, 08:05   #37
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

Quote:
Originally Posted by noelex 77 View Post
Genasun have got some very useful charge controllers for boats.

There are really only 3 common ways to reduce the panel output
Switch it off and on
Switch it off and on very rapidly . This is PWM.
Bypass the power to a dump resistor.

The dump resistor requires a lot of heat sinking which the Genasuns do not have. That leaves the first and second option. PWM is far superior to much slower switching.

There manuals are very short on technical details , but PWM is the way all similar regulators function. There are other technical possibilities that could be used and Gensun an are innovative company
If Gensun do not use PWM how is the regulation done?
Here's what I got from the head engineer at Genasun:

"PWM still charges the battery with brief pulses of full current; we
smoothly regulate the voltage/current to ensure very low ripple in
both.

Think of it as PWM on crack: the panel current is switched on and off
at tens to hundreds of kilohertz (most PWM is on the order of 300Hz),
then put it through a filter so the battery see almost pure DC voltage
and current."


And great info from gotboating now...
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Old 13-09-2011, 10:00   #38
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

Quote:
Originally Posted by OceanPlanet View Post
Here's what I got from the head engineer at Genasun:

"PWM still charges the battery with brief pulses of full current; we
smoothly regulate the voltage/current to ensure very low ripple in
both.

Think of it as PWM on crack: the panel current is switched on and off
at tens to hundreds of kilohertz (most PWM is on the order of 300Hz),
then put it through a filter so the battery see almost pure DC voltage
and current."


And great info from gotboating now...
Thanks its always good to get technical info, but what they are saying is that use PWM, but at a higher frequency than most. Its still PWM.

The higher frequency may help reduce the voltage ripple, but I cannot see that making much difference to lead acid batteries. Some would even argue that the small voltage fluctuations are helpful.

Still it seems to me they are a company that thinks innovatively which is always welcome.

Goboatingnow will probably take issue with them describing PWM as the panel current is switched on and off”
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Old 13-09-2011, 15:31   #39
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It's just a standard PWM buck regulator Typical switching frequencies these days are 300khz to 1Mhz. The battery is charged with pure DC. The panels are not switched off and on why would they. Solar panels supply only the power the source needs.

Solar companies constantly try and bamboozle users with PWM buzzwords. All it is is simple common or garden switch mode dc dc conversion.

Nor does PWM indicates one stage,yea stage or any stage battery charging either.

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Old 13-09-2011, 15:39   #40
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Gensuns. Descriptions are laughable. A sort of baby talk for electrical toddlers. " the little elections all run downhill to the resistor " sort of techno babble, usually written by a marketing exec, whose exposure to electronics consists of random
Jabbering at his or her iPhone

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Old 13-09-2011, 16:02   #41
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

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Originally Posted by goboatingnow View Post
The panels are not switched off and on why would they. Solar panels supply only the power the source needs.
Dave
Dave I am I puzzled by these comments.
Is not the essence of PWM, which is used by nearly all solar regulators, to switch the panels rapidly off and on when regulation is required ?
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Old 13-09-2011, 16:20   #42
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

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Originally Posted by goboatingnow View Post
Gensuns. Descriptions are laughable. A sort of baby talk for electrical toddlers. " the little elections all run downhill to the resistor " sort of techno babble, usually written by a marketing exec, whose exposure to electronics consists of random
Jabbering at his or her iPhone

Dave
Well, they don't really even have a marketing exec. Just a few MIT engineers, and the one answering my question obviously dumbed it down for me. Which I appreciate, all things considered...
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Old 13-09-2011, 16:57   #43
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Quote:
Originally Posted by noelex 77

Dave I am I puzzled by these comments.
Is not the essence of PWM, which is used by nearly all solar regulators, to switch the panels rapidly off and on when regulation is required ?
No it doesn't switch the panel on and off. ) well not in the way you mean, in switching convertors the input Sourve does see some complex current sinks especially transients, switched mode is hard on the source ) The PWM is just a standard buck convertor. The PWM is the internal switching signal used to switch the inductor current. Read up a little on buck boost conversion

Anyway why would you want to turn the panel off and on. It's a current source it only delivers what the load needs.

Think of it like this. Connect a 5w bulb of suitable voltage across say a 100 watt panel. The bulb lights. So the panel is producing 5 watts what's happening to the other 95. It's not actually producing any more then 5 watts. Yet if I connect a 50 watt bulb the same panel powers it. (both this bulbs have different impedance)

A regulator looks the same if the requirement of the load is high current the input impedance is effectively low. At lower load currents that impedance is higher. Hence you "control" the output current and the input so follows. ( this is all a little simplistic a description, but I have to start somewhere)

People always seem to think the panel produces X amps and somehow those amps "have to be consumed" that's not how it works.

What a solar regulator is doing is output regulation not input regulation. It's not " controlling" the source.

Dave

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Old 13-09-2011, 17:38   #44
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

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Originally Posted by goboatingnow View Post
No it doesn't switch the panel on and off. ) well not in the way you mean, in switching convertors the input Sourve does see some complex current sinks especially transients, switched mode is hard on the source ) The PWM is just a standard buck convertor. The PWM is the internal switching signal used to switch the inductor current. Read up a little on buck boost conversion

Anyway why would you want to turn the panel off and on. It's a current source it only delivers what the load needs.

Think of it like this. Connect a 5w bulb of suitable voltage across say a 100 watt panel. The bulb lights. So the panel is producing 5 watts what's happening to the other 95. It's not actually producing any more then 5 watts. Yet if I connect a 50 watt bulb the same panel powers it. (both this bulbs have different impedance)

A regulator looks the same if the requirement of the load is high current the input impedance is effectively low. At lower load currents that impedance is higher. Hence you "control" the output current and the input so follows. ( this is all a little simplistic a description, but I have to start somewhere)

People always seem to think the panel produces X amps and somehow those amps "have to be consumed" that's not how it works.

What a solar regulator is doing is output regulation not input regulation. It's not " controlling" the source.

Dave

Dave
If we connected a 12v 5w bulb to a 100w nominal 12v panel in full sun witout regulation, it would very rapidly blow. The voltage would immediately rise to close to the VOC which is about 21v.
In a same way the solar panel would increase the voltage of a charged 12v battery to a damaging level (unless it was a very ,very large battery)
By rapidly switching the solar panel off and on with PWM we can reduce the current so the voltage stays at a safe level.
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Old 13-09-2011, 18:07   #45
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Re: 14.6vdc Bulk 13.6vdc Float - So What Charge Rate ?

Quote:
Originally Posted by OceanPlanet View Post
Here's what I got from the head engineer at Genasun:

"PWM still charges the battery with brief pulses of full current; we
smoothly regulate the voltage/current to ensure very low ripple in
both.

Think of it as PWM on crack: the panel current is switched on and off
at tens to hundreds of kilohertz (most PWM is on the order of 300Hz),
then put it through a filter so the battery see almost pure DC voltage
and current."


And great info from gotboating now...
Excellent info! I must be one of those "electrical toddlers".. This is what we were talking about the other day on the phone, and today on the launch.

Thanks for that explanation it makes it much clearer and I can now understand why a friend who I suggested buy one saw such a dramatic improvement in his charging performance compared to a cheap shunting regulator.

As we discussed I will place an order for two tomorrow for upcoming installations. Should I go through you or just call Cambridge..?

Again, really appreciate the "technical" explanation..
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