Solar charge controller

[Adamhagan]

I just installed a 100W ramsond solar panel and a Sunforce 10amp charge controller. I have it routed through a control switch for either solar or wind generator, then to a circuit breaker and amp meter.

My question: The charge controller put the batteries at 14volts at which point I shut it down fearing overcharging. My bank is 2 optima bluetop AGM. I called Sunforce and they state the controller will switch to maintain at 14.2volts.

Will this controller damage the sensitive AGM's? My 110 volt battery charger only charges to 12.5volts. I will be transitioning from a slip to a mooring so the solar will be necessary.

Thanks and sorry for my ignorance in advance.

[Paul D.]

This page may help clarify the charging pattern for the Optima AGM's Scroll down for the Bluetop

http://www.optimabatteries.com/us/en/su ... /charging/

You may check with Sunforce again and describe the recommended pattern and see what the charge controller will do. If that is not helpful I would check with Ham Ferris at Hamilton Ferris. I have used their SMR on this page for ten years with a 60w panel while on a mooring and it has been terrific. I imagine your controller would be similar.

http://www.hamiltonferris.com/products/ ... ontrols/73

I have T-105 lead acid batteries however. Ham will sort your situation out if needed.

Good luck,

[Russell]

14.2 is fine, I would be much more concerned about your shore power charger only charging to 12.5, constant undercharging damaging as well.

If you are going to be dependent on your solar for primary charging, I would consider a better charge controller, especially since you are using a sensitive type of battery. Those Sunforce controllers are as basic as they get, they are not MPPT and I dont even think they are 3 stage "smart" controllers. BlueSky controllers have generally been considered the better controllers out there, though some new brands may have come up in the last few years that I am unfamiliar with that might be good as well.

[svreleaseme]

This page will help as well. http://www.emarineinc.com/pages/Batteries-101.html

[Adamhagan]

This page may help clarify the charging pattern for the Optima AGM's Scroll down for the Bluetop

http://www.optimabatteries.com/us/en/su ... /charging/

You may check with Sunforce again and describe the recommended pattern and see what the charge controller will do. If that is not helpful I would check with Ham Ferris at Hamilton Ferris. I have used their SMR on this page for ten years with a 60w panel while on a mooring and it has been terrific. I imagine your controller would be similar.

http://www.hamiltonferris.com/products/ ... ontrols/73

I have T-105 lead acid batteries however. Ham will sort your situation out if needed.

Good luck,

Thanks everyone!

I spoke with Sunforce and there is no adjustment and it will not work. They did have good customer service. From the specs on my batter I will need a float charge to maintain 13.2-13.8. The guys at Hamilton ferris were extremely helpful and I should have it installed shortly after my arrival in NYC.

[hilbert]

MPPT controllers allow for input voltage conversion that boosts the current over wider operating conditions.
Very cool, but more importantly the higher priced units generally have better float control.

Beware of inexpensive commercial ON-OFF regulators.
They have a simple switching device (mechanical relay, transistor or MOSFET), that cycles the full current on/off.
This is not good for the batteries or sensitive electronic devices.

I found schematics for an elegant linear shunt regulator. As the author writes:
"The circuit presented here uses linear shunt regulation. Simply spoken, it burns off all excess energy
from the panel, keeping output voltage constant. At times when the solar panel output is equal or greater
than the load, and the battery is fully charged, the load gets its power from the panel, while the battery
rests at full charge. Five years battery lifetime are entirely normal with this system, while the same
batteries last only two to three years when used with pulsing regulators!"
http://ludens.cl/Electron/solarreg/Solarr~1.htm

I built Ludens 7 amp circuit and I was surprised at how well it works. The float voltage is constant and easily adjusted to 1/100 of a volt.
This is about as good as it gets for a shunt regulator.

[Maine Sail]

Here's a comparison I did of an MPPT and a shunter/on/off controller.

http://www.youtube.com/watch?v=-uhj6dgj ... 3RpGnxVwFw

[hilbert]

Maine Sail, Thanks for another informative video.

Here is a graph of current vs. voltage for my linear shunt controller. There is a drain on the battery until the sun hits the panel at about 10:00 am. The current and voltage rise until the voltage reaches 13.8. Then the current begins decline while the battery voltage remains at 13.8 volts and the panel supplies current to the load.


This was a good solution for maintaining batteries with a low capacity and relatively low voltage panel.
MPPT controllers don't always work efficiently with low capacity panels or in low light conditions.

I am now in the process of replacing a 20 watt panel.
The new panel is 200 watts with an open circuit voltage Voc of 33.2 volts, which is ideal for an MPPT controller.
I will be using BZ Products MPPT250 in this installation.

[Maine Sail]

Please do your homework on the BZ MPPT's before plunking down... I have removed two of these units, one failed and one had so much interference on the VHF that the VHF was literally unusable. Replaced it with, Genasun and zero issues and better harvesting per day on average.

They also take their sweet time checking the OCV of the panel and seem to spend a lot of time OFF rather than ON. Perhaps they've gotten better but I hear an awful lot of grumbling about them and have witnessed these issues myself. In fact last year at Annapolis I was speaking with another marine electrical systems guy who is also manufacturer of water makers, alternators etc. who had a BZ on his own boat. His failed on him three times IIRC. He said BZ was good about repairing it but he was in Mexico and spent nearly as much as the unit costs in shipping to and from BZ for repairs....

I would be glad to give you his contact info off line....

A dynamic tacking MPPT will almost always perform better as it is constantly testing the voltage/capability of the panel. Instead of disconnecting the loads, to check the panel voltage to maximize current, they test what it can push to, multiple times per second, and recalculates on the fly.

The Genasun MPPT's work tremendously well even on small panels, it is what they were designed for, and also kick on bright and early in the morning. They use top shelf products inside the controller, build it specifically for the marine environment, and they are extremely efficient thus a plastic case due to minimal wasted heat. The only draw back to Genasun right now is that they stop at a 10A controller. They are coming out with bigger versions and ones that will have a computer interface for unlimited custom programming.

I have yet to have any install where a good dynamic tracking MPPT did not outperform a PWM or shunting controller in every case. I do about 1-2 solar installs per week during the season.

If you want a really, really sweet MPPT controller Rogue will be shipping their new model in a few weeks. While not inexpensive they are very, very sweet controllers. He sells direct so there are not multiple layers of distribution. Essentially you get more quality for your money. I suspect the street price on the new one will be in the $330.00 range... I can't wait to get my hands on the new model!!

If I am not using Genasun MPPT's, Rogue is my next choice above Outback, Morningstar & Blue Sky (in order of what I think of them)..

Again just do some homework on BZ. I am NOT suggesting you don't buy one, just urging you to do some home work on the product. Perhaps they've addressed noise issues etc. but once you get bitten or have issues you tend to get gun shy. I do like that they are made in the US but so are Genasun, Rogue and others...

The only other solar controllers I have seen physically fail are eBay Chinese units... Controllers are usually extremely reliable..

For marine installations these are some of my Favorite brands of controllers, from not just an engineering & performance perspective, but these companies all have good support & are very reliable products too.

Genasun (for smaller arrays): http://genasun.com/products-store/mppt- ... ntrollers/

Rogue Power Technologies (one controller/one guy EXCELLENT PRODUCT): http://www.roguepowertech.com/index.htm

Outback (For larger arrays): http://www.outbackpower.com/products/ch ... s/flexmax/

Morning Star (all size ranges): http://www.morningstarcorp.com/en/products

Blue Sky (all size ranges): http://www.blueskyenergyinc.com/products/

[Brian2]

Hello,

I see from the Genasun GV-5 Lead-Acid online manual that it has two ouputs and can be connected to a battery and also to a load. Can the "load" be another battery?

I have a 50W 3A panel and use a Sunforce controller. The Sunforce has been good for my small needs, but once the battery is charged, the controller constantly (well, frequently) switches on and off so I am thinking of changine to the Genasun GV-5 Lead-Acid controller.

Brian

[hilbert]

Please do your homework on the BZ MPPT's before plunking down...

Thanks for the heads up.

[Maine Sail]

Hello,

I see from the Genasun GV-5 Lead-Acid online manual that it has two ouputs and can be connected to a battery and also to a load. Can the "load" be another battery?

I have a 50W 3A panel and use a Sunforce controller. The Sunforce has been good for my small needs, but once the battery is charged, the controller constantly (well, frequently) switches on and off so I am thinking of changine to the Genasun GV-5 Lead-Acid controller.

Brian

Brian,

It is a "load" output not a charging output. For example lets say you wanted to leave a 12V powered ventilation fan going 24/7 but did not want it connected direct to the battery bank. You could use the "load" output and wire it direct to the fan. If there was no sun or the battery voltage got too low the load would automatically disconnect where it would not if direct connected to the battery. Also when the battery is full and not taking much current the load terminal can capture solar power that is being wasted. With a controller and panel that small there will be little to no "waste" so the load terminal is often of little use on a sailboat.....

In most instances a "start" battery will not need a top up charge but every three to four weeks, depending upon temps. This you can do manually with the BOTH setting and just feed the solar to the house bank.

Alternatively you can use a latching relay like the Sterling Power Pro-Latch R: http://sterling-power-usa.com/SterlingP ... tch-R.aspx

or a Xantrex Echo Charger: http://www.xantrex.com/power-products/p ... arger.aspx

Or a Balmar Duo Charge: http://www.balmar.net/duo-charge.html

These devices also work with the alternator and shore charger to keep the start bank topped up. The Duo and Echo do require that the alt and all charge sources be directly fed to the house bank though.

[Paul D.]

I have used an Echo Charger for ten years between the house bank (2 T-105's) and the start battery. It has worked fine and there is no need to adjust it as it is all automatic and pretty safe. This device keeps the start battery charged through the winter as I leave the solar panel outside the shrink wrap hooked to the controller. Each spring the batteries are fully charged and ready to go. There has been no trouble with it. I recommend this unit.

[chase]

Same here with the Genasun and Echo Charge. The system works nicely.

Maine Sail, I have not had a chance to re-wire my alternator directly to house bank, but when operating the boat, I am always switched to the house bank, with the echo charge connected to the backup start battery. The Echo Charge seems to work fine this way, with current coming from house bank when under power, and also from the Genasun.

I'm assuming this picture changes as soon as the switch is turned to ALL or directly to the start battery which is normally charged via the Echo Charge? Am I missing something here?

Thx-

Chase

[Maine Sail]

Same here with the Genasun and Echo Charge. The system works nicely.

Maine Sail, I have not had a chance to re-wire my alternator directly to house bank, but when operating the boat, I am always switched to the house bank, with the echo charge connected to the backup start battery. The Echo Charge seems to work fine this way, with current coming from house bank when under power, and also from the Genasun.

I'm assuming this picture changes as soon as the switch is turned to ALL or directly to the start battery which is normally charged via the Echo Charge? Am I missing something here?

Thx-

Chase

The Echo Charger is a one-way device as is the Balmar Duo Charge. This is why they recommend the devices be placed between batteries and then the charge source run to the house bank.

The only time I have ever seen an Echo Charger fail is when it was wired so the charge sources could be switched via the battery switch.

You can always use the BOTH feature if you need to speed charge the second bank and you don't feel the 15A is enough, but this would be a rare situation.

IMHO the failure of that one unit was caused by all the switching of charge sources being done, they are simply not designed to be wired like this.. Also if you have the switch set to bank #2 bank #1 will not get charged because the Echo only works in one direction.

One more point about re-routing the alt to the house bank is that you no longer run a risk of frying the alternator diodes with the battery switch. You essentially turn your battery switch into a use switch and not a charge directing and use switch.

If re-routing the alt to the house bank:

*Fuse the wire within 7" of the house bank

*Install a service disconnect switch so when mechanics are working on the boat they have an easy way to remove power from the alternator. I prefer this switch to be in the engine bay and clearly labeled so guests will never see it nor touch it, but mechanics will..

This is an example of an alternator service disconnect switch: