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.

[BFL13]

Not clear what the set- up is there, but you can have a situation where the controller thinks it is doing the right thing by getting the battery to 14.x, but the battery is only at less than that. This would be from voltage drop on the controller to battery connection.

This leads to undercharging because the batteries actually never get to the high voltage set point the controller is set to.

Voltage drop is related to the amps on that path and the R of that path. High R is bad, such as with too-thin wire for its length, and loose connections.

Besides a better controller, you should check that controller to battery path ( pos and neg paths--check each one) or the same thing might happen with the new controller.

[wopachop]

Changed the solar controller to charge profile #1 for flooded batteries. Took out 46ah last night and this is what it did.

At 2:30pm today i disconnected the controller to see if it would reset and start charging again. Didnt really work.

Seems like a horrible controller. Charges for like 4 hours and shuts off till the next day.

[BFL13]

wopachop wrote:
On day 3 and 4 it got up to 14.7 measured at the battery post. Isn't that too high and a sign that charge profile #2 isn't working right?

No. First the nominal AGM Vabs of 14.4 might be affected by it being temp adjusted, if it is lower than 77F out. Second, who says a few minutes at 14.7 is bad for your brand of AGMs? Probably doing them good!

What is not working right is the time at 14.x. You need nearly all day in daylight where it holds at that voltage, and it should be at the Vabs your batteries are specified for.

You need to know that Vabs spec first, before getting any charging equipment, so they will match.

You seem to be way too worried about too much time at 14.x, instead of what the battery spec says to do ?

It is clear that your AGMs died from under charging. Not enough time at Vabs mainly. No observation of when reaching 0.5a/100AH before dropping to Float voltage too.

With your new 6v Wets you can take it easier and just use your hydrometer to see if you are on track. If not, change your ways accordingly. Easy peasy. AGMs are not so easy. Eg, with Wets , you don't need the ammeter; you have the hydrometer.

[wopachop]

On day 3 and 4 it got up to 14.7 measured at the battery post. Isn't that too high and a sign that charge profile #2 isn't working right?

[BFL13]

Your charging profile says it does only two hours at 14.4 if the battery falls below 12.3 (about 62% full with Wets, but is under 50% with my AGMS which have 12.4 as 50% and 13 as full resting) It will do 14.4v for only one hour each morning! It takes more like half a day from there at 14.4 to fully recharge the battery bank. Usually there is not enough daylight in a day unless you start early with a mostly high amp generator recharge before going to solar to finish it off.

Your graph shows only brief moments at 14.4 or so, the rest of the time under 14. Is that the one hour you get?

Horrible charging profile! Undercharging badly.

EG, the standard EPSolar charging profile is to stay in Bulk until the batts get to 14.6ish, then hold that as the Absorption voltage for two hours, then drops to 13.6v. It could take all day just to get the bank up to 14.6 and be dark before the two hours is up. It depends! Note that is fixed profile unless you get one you can adjust--some require an extra gizmo to adjust them, or else you stay with the fixed.

AGMs can take 8 hours or whatever it takes AFTER they get to their AbsV of 14.4 or whatever where they need to stay at 14.x until amps to the battery tapers to 0.5a/100AH of bank. Very hard to do on solar even with a 12 hour daylight time.

Lots of better PWM controllers out there than that particular Go-Power one. The Grape seems like a good choice for all its features.

[wopachop]

You guys were right GoPower GP-pwm-30 controller does allow you to choose flooded or gel. I checked and its been set to #2 agm this whole time.

I took 50ah out of my dual 6v flooded batteries and hooked to the solar. The controller is still set to #2 agm.

Here is what it did the last 4 days. Seems like the voltage is a tad high? Maybe thats what killed my AGM in under 2 years.

[wopachop]

Thanks for all the advice. The go power is around 5 years old. Will post a pic of the model later. I'm tracking its performance. Looks like it hit 14.1 and then shut off.

Ashamed to say after 2 years I still havnt read or skimmed all the manuals. Will check the go power solar tonight for settings.

I think the way to go is a new converter. Will have to read back cause a lot of good info to absorb like a battery.

[BFL13]

The problem with "AGM setting" on chargers is that voltage is usually /always lower than the Flooded voltage setting.

AGMs have charging specs all over the map, so a low voltage setting could undercharge a particular AGM. You have to know the actual specs for your AGMs to get it right.

Then you need a charger that can meet those specs. EG, Lifeline wants 14.4v at 77F, but my AGMs specify 14.5 to 14.9 so with them I would use the Flooded setting with a non-adjustable voltage charger.

BTW Go-Power was sold to an outfit in California recently, so they might have changed their ways. They used to be expensive compared with other similar products, which can't be good for business.

[StirCrazy]

wopachop wrote:

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

Go Power is generally known for using higher quality components in there kits, and I also have there stuff and have had the system on my old 6V bank for 4 years now. there is a setting on the charge controller for agm or lead acid, maybe if it was set wrong that could be the issue.

my batteries were 10 years old when I started with the solar, and no issues over the last 4 years at all

is the converter a normal junky 2 stage converter, that is not set up for agm? if it is the first thing I would do is I got them to take that out and put in a proper 3 stage charger with equalization.

Steve

[BFL13]

wopachop wrote:
What about people off the grid? If they have huge battery banks and a smaller solar setup does that mean they suffer from too low of charge current and lower battery life?

I come from RC toys and lipo batteries where low and slow is ideal.

Yes, exactly. One member here , eg, reduced from six batteries to four so he could get the four recharged during daylight time with his solar, where he could not get six done before dark.

[wopachop]

What about people off the grid? If they have huge battery banks and a smaller solar setup does that mean they suffer from too low of charge current and lower battery life?

I come from RC toys and lipo batteries where low and slow is ideal.

[BFL13]

The temps swings don't matter for while using the batts, but you will want to set the proper voltage for when recharging the batteries using the converter and generator.

That would most likely be in the morning daytime, so if 14.4 is about right for what that temp usually is in the forenoon (use less than 14.8 if it is over 77F at the time), you could get a 14.4v PD converter with CW. Or to do it right no matter what, get the PowerMax LK (which is cheaper too).


Solar is just to extend the time between generator/shore power via converter recharges, so upgrading the solar controller is not vital really.

[wopachop]

That sounds great thanks!! We camp in the desert so there are big temp swings. This summer will be 110F+. Winter time is almost freezing.

I have my batteries disconnected. Inside the trailer is a little USB power station that shows voltage.

My wfco was just putting out 14.4v. With no batteries attached. Whats the dealio with that? Its usually 13.4 when on shore power and battery disconnect in the off position.

[BFL13]

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.

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

The Parallax with Temp Assure has that but is based on 14.2v nominal instead of 14.8v, and is expensive in comparison.

Here is how to operate the PowerMax LK. (para 10) You need a small screwdriver and a flashlight to see what you are doing with the screwdriver. You put your multimeter probes in the set-screw converter DC output terminals set for "12v" voltages, and set the voltage with the pot.

It will hold that voltage forever until you change it. Now you connect to the battery bank with say #4 short wires, and good to go.

https://powermaxconverters.com/wp-content/uploads/2018/05/PM3-12V-LK-Manual-2018.pdf