solar disconnect switch

[wopachop]

I want to install a switch to disconnect my 155w panel from the controller. The regular battery disconnects are so big. Any harm using a small toggle? Or maybe there are smaller disconnects? I looked around amazon and e bay. Seems like im seeing the same 3 products under different names.

Why?
Trailer is on shore power mostly. No need to float fully charged batteries every single day. I think thats what killed my agm batteries in under 2 years.

[2oldman]

wopachop wrote:
Guess it depends on the type of camping. A lot of my friends have the honda 2000s and run them the entire time.

Yikes.

[wopachop]

Guess it depends on the type of camping. A lot of my friends have the honda 2000s and run them the entire time.

Does anyone make a decent converter with a temp probe? If not then adjusting by hand is doable.

[2oldman]

BFL13 wrote:
Yes, some folks never heard of an inverter.

Perhaps inverters are too complicated. Generators are easy to understand.

[BFL13]

2oldman wrote:

wopachop wrote:
Previous owner said they would run the genny practically 24/7 while camping.

People often take heat on here for wanting to watch TV or use the internet while camping, as if that's just not right.

But running a generator 24/7 ? Ugh. That really isn't right.

Yes, some folks have never heard of an inverter. Too easy. Use the inverter for 120v things during campground "quiet hours" and then recharge the batteries with generator during "generator hours".

[2oldman]

wopachop wrote:
Previous owner said they would run the genny practically 24/7 while camping.

People often take heat on here for wanting to watch TV or use the internet while camping, as if that's just not right.

But running a generator 24/7 ? Ugh. That really isn't right.

[BFL13]

wopachop wrote:
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)

Max 8 amnps is about right for flat on the roof 155w panel. No problem there.

You can get a fancier controller, but not really needed if you get the 6s. Good idea instead of fussy AGMs that you don't have the instruments to look after.

You need new converter for sure, that can do your 6s. The usual 14.4v converter is unsat for that too. A pair of 6s can take 60 amps easy and that can be done with a 2000w gen. My 75 amper needs the 2200w gen.

Since the 6s want 14.8v at 77F and that is 15.2v at 33F, I like my PowerMax (same as a Randy "Boondocker") adjustable voltage LK model converter so I can do it right in the winter outside. YMMV on that.

The PD is easier to operate with just the CW, but lacks the adjustable voltage, so it is only correct at 77F. How much that matters to your scenario is unknown except to you!

EDIT--you can still get older PowerMax and Boondocker models that do not have the adjustable voltage. Beware! Get that clear with Randy if you go there! The newer "LK" models are not expensive anyway. Eg:

https://www.boatandrvaccessories.com/products/powermax-pm3-60lk-12-volts-60-amp-power-converter-batt...

[pianotuna]

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...

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)

[time2roll]

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

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

[wopachop]

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)

[DrewE]

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.

[BFL13]

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

[pianotuna]

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.

[time2roll]

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.

[pianotuna]

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.

[pianotuna]

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.