solar disconnect switch

Hi,

You need to be able to do 20% charge rate for AGM. 10% may allow history to repeat itself. Charge until only 1/2 amp per 100 amp-hours of battery bank is being shown (i.e. for a 220 amp bank, 1.1 amps)

Yes, replace the converter.

You can go for a Grape Solar Controller with temperature compensation which will handle up to 40 amps of input. It has blue tooth for programing. Available at Home Depot for approximately $70 bucks.

https://www.homedepot.com/p/Grape-Solar-COMET-12-24-Volt-40-Amp-Solar-Charge-Controller-GS-PWM-COMET-40/305498558

wopachop wrote:
Now im thinking a better converter would be the way to go. Since i only have a single 155w panel i would need much more if i wanted to consider my solar the main charge source.

Other option, like i posted before, is using my RC charger. Thing was like $300. Im trying to figure out if i can make it do a constant voltage equalization charge. If thats the case i can discharge the batts at home and then blast them with a strong charge. My RC charger does have a Pb setting and i can choose 6v. I think you guys told me i want 10% so around 20amps would be ideal?

(the trailer has AGM currently, but switching to 6v)

Call Randy but I believe this PD4655 is a direct replacement for the WFCO board.

http://www.bestconverter.com/4655L-Wildkat_c_229.html

So it sounds like you guys are saying its possible the AGMs died under 2 years because of being undercharged.

Yes the solar controller is cheap. GoPower 30amp Pwm. Max i see at the batteries is about 8amps. No temp compensation.

It is the wfco converter. Previous owner said they would run the genny practically 24/7 while camping. So there is a chance the batteries were never really discharged and hit with a big amp charge. I measured 14 or 17amps from the wfco. But with solar and genny power there is a chance the converter was mostly in float mode?

Plan was to invest in a better solar charge controller. Now im thinking a better converter would be the way to go. Since i only have a single 155w panel i would need much more if i wanted to consider my solar the main charge source.

Other option, like i posted before, is using my RC charger. Thing was like $300. Im trying to figure out if i can make it do a constant voltage equalization charge. If thats the case i can discharge the batts at home and then blast them with a strong charge. My RC charger does have a Pb setting and i can choose 6v. I think you guys told me i want 10% so around 20amps would be ideal?

(the trailer has AGM currently, but switching to 6v)

For a switch, do pay attention to check that the current ratings are valid for DC current. Many switches are only rated for AC operation, or have a much lower DC current than AC current rating. The reason is simple: as the AC waveform crosses zero volts 120 times each second, any internal arcing that starts is quickly stopped at that point. Switching DC, even lower voltage DC, is rather harder on the switch.

That being said, you probably could get away with an AC switch in practice, especially since this won't be used too frequently. The failure mode would typically be that the switch fails to switch off when toggled because the internal contacts have become welded together. It's not at all likely to cause a fire or anything like that, and this is hardly a life safety critical sort of application where the switch not working is going to pose a genuine danger to someone.

The "panel voltage" is Vmp with MPPT only in Bulk. Vmp is about 17 with a "12v" panel and about 30 with a "24v" panel. Imp will be less than Isc in Bulk.

With PWM you have to use the IV curve for battery voltage to get the amps. With MPPT in PWM (Absorb and Float) it depends on the load too what the "apparent" voltage will be on the panel to controller line.

The current you have on the panel to controller line is sometimes over the panel Isc value

No power while sun is down, no power from covering panel completely, and no power past a switch to the controller are all the same. But a dc rated switch is a lot more convenient than the first two.

BFL13 wrote:
Switch is good for isolating panel from controller before disconnecting battery. Idea of using a cover on the panel without disconnecting it does not seem the same somehow, but not sure.

wopachop wrote:
Everything i read says a constant float charge is harmful to both flooded and sealed.

Maybe disconnect the converter to avoid constant float.
Solar cycles daily with the sun and clouds.

Is that a WFCO by any chance? All the more reason to disconnect.

I'll have to tell my cousin his fluke meter was wrong and we were not getting 33 volts presented to the MPPT controller, as well as 17 amps @ 14.4 volts to the battery bank. Such a shame when you can't trust measuring devices.

You don't know me Ski Pro 3, but I rarely speculate preferring real life measurements with the best equipment I can borrow or afford.

Ski Pro 3 wrote:

pianotuna wrote:
Ski Pro 3,

Panels are often 17 volts. Much higher voltage panels are also available. Mine are wired in series/parallel giving a nominal voltage of 33 on the input side of the controller.

That is the open circuit rating for the panel voltage. No current. Once the circuit is configured, the measured voltage at the solar panel won't be 17 volts, or 33 as the case may be. A switch isn't rated on it's voltage as much as it's rated on it's amperage.

Hi,

90 days in campgrounds over the last 1900 days of full time.

What MAY have shortened the Marine batteries life was a lousy solar controller that does not have temperature compensation, nor adjustable voltage set points.

I'd point out to you that solar is NOT a constant float. There is no charging going on when the sun is down.

My previous bank was 875 amp-hours of Marine jars. The were solar floated from day one and lasted for 9 years. I was able to equalize them via solar using bank switching.

My current bank is used AGM telecom jars that have been in service for 5 years. They, too, have been solar floated since the day I got them. I push them HARD (up to 225 amps draw).

For AGM to last one needs to be able to charge them at 0.2 C (20 amps for each 100 amp-hours of capacity). If this is not done, they will sulfate. It is MUCH harder to recover an AGM from such abuse and requires the end user to "dance on the needles".

A disconnect switch between the panels and the controller is a good plan, but it has almost nothing to do with charging. It is to protect the controller from letting out the magic blue smoke.

wopachop wrote:

It seems like most people on this site go to campgrounds. So their trailer is either stored or hooked to shore power. If you have solar without a disconnect that means your batteries are always fully charged and every morning get cooked at 14.4v. I still think that is what killed my deep cycle marine batteries premature. I read the trojan link many times over the last few years. It does not recommend a constant float on both sealed and flooded.

pianotuna wrote:
Ski Pro 3,

Panels are often 17 volts. Much higher voltage panels are also available. Mine are wired in series/parallel giving a nominal voltage of 33 on the input side of the controller.

That is the open circuit rating for the panel voltage. No current. Once the circuit is configured, the measured voltage at the solar panel won't be 17 volts, or 33 as the case may be. A switch isn't rated on it's voltage as much as it's rated on it's amperage.