Adjustible Solar PV Controllers

[mitiempo]

Originally Posted by rgleason

Yes Alternator will charge to 80-85%
Solar will charge batteries to 98% over 1.5 days.
225ah battery bank.

Solar PV will probably be Soliban SR https://www.bruceschwab.com/solar-po...ian-flex-high/

For SR-62watt
Cells no. 14
Voc 8.9 V
Vmp 7.2 V
Isc 9 A
Ipm 8.6 A
For SR-50watt it is likely to be a little less.

Genasun controllers are very good.

But, why use such a low voltage panel with a boost controller (expensive) that cannot be adjusted to the correct voltage for the batteries?

You would be much better off with higher voltage panels and a controller or controllers that can be adjusted to any voltage - such as the voltage the battery manufacturer requires, like the Victron MPPT which are also much less expensive. It will definitely lead to longer battery life.

[john61ct]

Originally Posted by noelex 77

The absorption phase is not just the time after the absorption voltage is first reached, but the time when the absorption voltage is maintained.

Interesting, but in practice irrelevant to my main point, so to re-iterate that:

Assuming bank longevity is a high priority,

drop to Float, end of charge cycle should occur at 100% Full,

which is the ideal, should occur at least a few times per week,

very common failure to do this AKA premature infloatulation, murders many (most?) banks.

**If** endAmps does not directly control the drop to Float - which is the ideal

**then** the user should extend Absorb Hold Time setting(s)

until the problem has been eliminated.

The bank needs what it needs, getting to the 100% Full point as measured by trailing amps at Absorb V.

The volts and amps variations up to that point may help or hurt how often and how efficiently that happens.

And that is on the regulation circuitry of the charge source, as adjusted for that situation by the owner.

Now, the above is not solar specific, and assumes overall energy inputs are sufficient, obviously adding energy inputs or reducing consumption may be required.

___
As to the enormous variations in SC's AHT algorithms, and how it is counted, not really going to get into the weeds on that, too many variables.

My experience has been that as panel input watts decline, that is usually reflected as a drop in SC output **current**.

SC output voltage should **not** be affected, until you get to the point where hardly any useful energy is being produced.

____
Now if the **battery** voltage (negotiated between SC output current level and SoC, resistance) is periodically dropping below then rising to the Absorb setpoint

And your SC is tracking that and counting Absorb time that precisely, then great, but really not relevant to the more general case, 99% of charge sources do not include such features.

Obviously then the settings for AHT will nominally be much lower numbers than the more usual primitive ones.

If that difference is the source of our difference, Aha!

But does not change the main point above, the need for the user to adjust AHT in order to ensure endAmps is regularly reached at Absorb before Float.

[rgleason]

I am following Ocean Plant suggestions, and will ask about this, but I expect that I'll be told that the Genasun Boost controller will enable a longer and more effective charge period (longer hours). Splitting the areas of the dodger on port/starboard side help to solve the boom shadow problem. It will be interesting to learn more from them.


I would like to extend the panels with additional ones, but much of the cabin top is broken into small areas by handrails, hatches etc. There is one possible location just forward of the dodger about 32" x 32" which covers the companionway slider, but I think this area is lower and subject to shade at different times than the dodger. If used it should be separately connected and controlled. I suppose I could use some areas of deck up towards the bow, but those surfaces need to be non-skid.

Originally Posted by mitiempo

Genasun controllers are very good.

But, why use such a low voltage panel with a boost controller (expensive) that cannot be adjusted to the correct voltage for the batteries?

You would be much better off with higher voltage panels and a controller or controllers that can be adjusted to any voltage - such as the voltage the battery manufacturer requires, like the Victron MPPT which are also much less expensive. It will definitely lead to longer battery life.

[mitiempo]

Originally Posted by rgleason

I am following Ocean Plant suggestions, and will ask about this, but I expect that I'll be told that the Genasun Boost controller will enable a longer and more effective charge period (longer hours). Splitting the areas of the dodger on port/starboard side help to solve the boom shadow problem. It will be interesting to learn more from them.


I would like to extend the panels with additional ones, but much of the cabin top is broken into small areas by handrails, hatches etc. There is one possible location just forward of the dodger about 32" x 32" which covers the companionway slider, but I think this area is lower and subject to shade at different times than the dodger. If used it should be separately connected and controlled. I suppose I could use some areas of deck up towards the bow, but those surfaces need to be non-skid.

The solar controller should be set to the voltage your battery manufacturer states. Genasun controllers (I sell them) are not adjustable. Victron controllers are fully adjustable.

On another point were the controller to ever fail when cruising good luck finding a boost controller outside of the US. With conventional higher voltage panels this is not a real issue.

[rgleason]

Mitiempo, you've helped me a lot with the electrical system diagram. Can I get higher voltage panels that small?
Aren't the panels just cells 5" or 6" square that produce between 2.8w and 4.5w that are joined in series to increase the voltage?

Gosh I thought solar would be easier choices.

[newhaul]

Originally Posted by rgleason

Mitiempo, you've helped me a lot with the electrical system diagram. Can I get higher voltage panels that small?
Aren't the panels just cells 5" or 6" square that produce between 2.8w and 4.5w that are joined in series to increase the voltage?

Gosh I thought solar would be easier choices.

there are several panels that are made that will fit in your available area that won't require a boost controller. Quick eBay search for 50 watt panels .
https://www.ebay.com/b/Solar-Panels/...59%2520W&rt=nc
Just take a look

[rgleason]

Newhaul. Yes, I was going to check out your suggestions and links. Thanks.

Three that might work:
Renology 50w flexible 18v $118
Sunpower 50w 25.5"x21.5" SPR-E-Flex-50 $118
Renology 50w 12v 26"x23.6" $117

I have a couple of questions about size, one of them has EFTE covering. I have no idea about quality or how long these will last, how much they will really output, if they are intended for marine environment, etc and there is no way that I know of being sure about who actually made these panels etc.

I know Bruce, supported his campaign in a minor way, and I know he sells products that he has tested and believes in. He is reasonably local (ME) and I have confidence in Ocean Planet. The panesl are expensive, but they are most likely to work as expected.

[rgleason]

We have so many controllers (charger, solar, regulator, etc) I'm interested in the idea of having a single good BM Battery Meter/Moniter that:
1. Acts as a Ah Counter.
2. State of Charge SOC meter.
3. Measures trailing amps properly.
4. Has Temperature compensation.

5. Has an No/Nc contact signal for when the batteries are Full,
so that all devices can be set on long enough absorption times so that they go to float once this signal is sent.
6. Has bluetooth communication to reduce wiring.



SC = Smart Controller?

AHT = Absorption Time?

Originally Posted by john61ct

Interesting, but in practice irrelevant to my main point, so to re-iterate that:


Assuming bank longevity is a high priority, drop to Float, end of charge cycle should occur at 100% Full, which is the ideal, should occur at least a few times per week, very common failure to do this AKA premature infloatulation, murders many (most?) banks.


**If** endAmps does not directly control the drop to Float - which is the ideal **then** the user should extend Absorb Hold Time setting(s) until the problem has been eliminated.

The bank needs what it needs, getting to the 100% Full point as measured by trailing amps at Absorb V. The volts and amps variations up to that point may help or hurt how often and how efficiently that happens.
And that is on the regulation circuitry of the charge source, as adjusted for that situation by the owner. Now, the above is not solar specific, and assumes overall energy inputs are sufficient, obviously adding energy inputs or reducing consumption may be required.
___
As to the enormous variations in SC's AHT algorithms, and how it is counted, not really going to get into the weeds on that, too many variables. My experience has been that as panel input watts decline, that is usually reflected as a drop in SC output **current**.
SC output voltage should **not** be affected, until you get to the point where hardly any useful energy is being produced.
____
Now if the **battery** voltage (negotiated between SC output current level and SoC, resistance) is periodically dropping below then rising to the Absorb setpoint
And your SC is tracking that and counting Absorb time that precisely, then great, but really not relevant to the more general case, 99% of charge sources do not include such features.

Obviously then the settings for AHT will nominally be much lower numbers than the more usual primitive ones.
If that difference is the source of our difference, Aha!
But does not change the main point above, the need for the user to adjust AHT in order to ensure endAmps is regularly reached at Absorb before Float.

[newhaul]

Originally Posted by rgleason

Newhaul. Yes, I was going to check out your suggestions and links. Thanks.

Three that might work:
Renology 50w flexible 18v $118
Sunpower 50w 25.5"x21.5" SPR-E-Flex-50 $118
Renology 50w 12v 26"x23.6" $117

I have a couple of questions about size, one of them has EFTE covering. I have no idea about quality or how long these will last, how much they will really output, if they are intended for marine environment, etc and there is no way that I know of being sure about who actually made these panels etc.

I know Bruce, supported his campaign in a minor way, and I know he sells products that he has tested and believes in. He is reasonably local (ME) and I have confidence in Ocean Planet. The panesl are expensive, but they are most likely to work as expected.

these are the same panels.
https://www.ebay.com/itm/Sunpower-18....c100005.m1851
Offer them $50 each for 2 or 4 bet they say yes on 4 panels for $50 each.

[rgleason]

Also perhaps acts as the battery sensor and control for all Controllers, setting when Bulk, Absorption and Float occur.

[OceanPlanet]

Originally Posted by newhaul

is there actually a legitimate reason for not using panels made for 12 v systems?
The Hqst panels I linked to are very good little panels that will easily maintain your batteries with a standard charge controller without the need for the expense for the boost charge controller.

Actually, yes. With small panels, for a given wattage, the full size cells in the low voltage high current panels lose less output in minor shading than the smaller cut cells in the higher voltage low current panels.

Because the cells are in series, and because in the higher voltage panels a higher percentage of the area of the smaller cells are shaded by the shade of lines, etc, a higher percentage of the current flowing through the cells is blocked.

Also, the higher voltage panel would need a good mppt controller anyhow to realize it's max potential output, the additional cost of a boost controller isn't much at all.

[john61ct]

Originally Posted by rgleason

Also perhaps acts as the battery sensor and control for all Controllers, setting when Bulk, Absorption and Float occur.

To Dream, the Impossible Dream. . .

Actually there are FOSS projects going in that direction, but few charge sources enable open standard interfaces to their proprietary comms protocols.

Victron does though. . .

And the combo I suggested above comes pretty close.

[rgleason]

Originally Posted by OceanPlanet

Actually, yes. With small panels, for a given wattage, the full size cells in the low voltage high current panels lose less output in minor shading than the smaller cut cells in the higher voltage low current panels.

Because the cells are in series, and because in the higher voltage panels a higher percentage of the area of the smaller cells are shaded by the shade of lines, etc, a higher percentage of the current flowing through the cells is blocked.

Also, the higher voltage panel would need a good mppt controller anyhow to realize it's max potential output, the additional cost of a boost controller isn't much at all.

Thank you for the explanation. Bruce.

Since we are trying to reach 100%SOC with solar, it has become clear that the solar controller needs to be adjustable so that it can be set for the battery manufacturer's specified settings, or 100%SOC is unlikely to be reached.

The Genasun GVB-8 Boost controllers (about $107) are not adjustable, however I expect that they do enable more extended operation of the the lower voltage gaining greater effective "sun" hours in the day, as well as wringing more amps out of partially shaded cells. - Is this true?

Also, since GVB-8 Boost is not adjustable, it the best way to assure achieving a full 100%SOC charge, to complete the process with an engine/alternator session of 1hr-30min (whatever time period uses up all the timed stages in the regulator programming for bulk and absorption) and then manually check the voltage and the trailing amps with both a reliable amp meter and a clampon amp meter at the batteries, until you are totally familiar with the process and have reached 0.005C (1/2 amp per 100ah Battery Capacity)?

(Also then it is time to push "RESET" on your AH Counter to set it to Full).

It's too bad Victron doesn't make a similar Boosting Controller, particularly with its other capabilities.

[rgleason]

John, help me. What is
SC?
AHT?
I have a hard time with these things.

[rgleason]

Originally Posted by newhaul

these are the same panels.
https://www.ebay.com/itm/Sunpower-18....c100005.m1851
Offer them $50 each for 2 or 4 bet they say yes on 4 panels for $50 each.

Max power:50W
Working voltage:18V
Open circuit voltage: 20V
Working current: peak near 2.5A
Short circuit current:2.8A
Size of panel:550*540*3mm
Material of solar panel: 1/2 sunpower solar cells


It is a very good price, however we don't know about the longevity and reliability. EFTE cover coating? And it probably does not have nearly the same UV layers as Soliban.

So how long is it expected to last? 1 year? 2 years? 3?

It is cheap enough so that you could start with these panels and try them to see how long they actually last, and how well they perform, and then make a decision after that period.

One advantage to this is you will be riding the technology curve down, theoretically (except Trump has disrupted that expectation recently with his changes to trade agreements), so the next purchase will be better and at less cost. Also since they are higher voltage panels you could use Victron mppt controllers.

At this point I have no idea which way is best. I expect they both will work to a certain extent. I believe Soliban will provide more output at greater cost, and probably be more reliable.