Is my system setup in a good way?

[PhillipVTE]

Hi, I hope I have put this post in a good place. But basicly I think I'm having issues with my solar system and I need some help.

My set up consists of
1x 100w 12v solar panel
1x 55ah leisure battery, lead acid
1x MPPT charge controller 30A

Basicly I have the above set up with some 12v led lights that are around 2w each I think (I know the amp they each take is 0.35A because that is what it says it's taking out on my display) but my battery runs flat very quickly (like an hour). The battery is less then a year old and I use the lights every day for about 2 hours. The battery was fine to begin with but over the last couple of weeks I noticed that the voltage will go all the way up to 14v volts in the daytime but will drop to around 12.5 during the night even if I haven't used anything during the charging time.

I not sure if I have my charge controller set up correctly or not

My charge controller is set to PV off: 13.8v
Is this right
I remember someone saying I red to charge it to something like 14.4v is that right?

[SunEagle]

Hello PhillipVTE and welcome to Solar Panel Talk

Well your system hardware sound about right. A 100 watt panel, 12v 55Ah battery, 30A MPPT CC.

The problem may be that you have under estimated your daily load. That battery can deliver ~ 55Ah x 12v x 25% = 165watt hours a day.

Depending on where you live that 100 watt panel should be able to put back about 200 watt hours even on the shortest day of the year.

My guess is that your battery is being drained by more then those LED lights or for some reason is not being charged back to 100% SOC because that MPPT is not working properly.

[Sunking]

The battery was fine to begin with but over the last couple of weeks I noticed that the voltage will go all the way up to 14v volts in the daytime but will drop to around 12.5 during the night even if I haven't used anything during the charging time.

So what is the problem? That is exactly what you should see.

You cannot use battery voltage to tell you anything about the State of Charge (SOC) while it is charging up or being discharged. Means nothing. The only time you can use voltage to get a rough idea of the battery SOC is when it has is Open Circuit Voltage (OCV) and rested for several hours. OCV means disconnected. Assuming you have a FLA battery what is your SOC according to the chart? The voltage you see at night...

[PNjunction]

Hi, I hope I have put this post in a good place. But basicly I think I'm having issues with my solar system and I need some help.

My charge controller is set to PV off: 13.8v
Is this right
I remember someone saying I red to charge it to something like 14.4v is that right?

From this distance, sounds like a cheap fake mppt controller, along with the fact that some of those fakes are "float only" types that only have the 13.8v setpoint, and there are no other user adjustable settings, which is entirely wrong for your daily discharge application.

Is this one of them? What exactly is the make / model of your controller?

Quick tip: For this type of inexpensive setup, take a step up in quality to something like a Morningstar Sunsaver 10A SS-10-12V. It's only pwm, BUT would be entirely adequate for your intended purpose and project budget.

[Guest]

Sounds like most of these guys buy and use fairly expensive batteries . As a Flooded Lead Acid (FLA) battery user from way back I can tell you that I hope to see the last of them soon. They have been made cheaper and cheaper over the years by various countries and companies and are a take .

They are now put out "Maintenance free" which means you can't mess with acid levels or see the cells.

So what happens ? Batteries seem a bit flat ... put them on the charger and go to bed. Does not take much of that to boil the electroite out of the battery as they conveniently leave a vent hole and they make a sales point of that . have to have it because batteries give off gas when charging. So the water is boiling away each time you charge them no matter how you charge them , and you can't replace it so the level is going down the cell walls gradually.

Amount of charge gradually reduces until it gets to a point where its dry ,completely sulphated up , waterless and it stops putting out.or taking in. Just had one 3 days ago on a boat I bought . Batteries 12 months old.

My advice? Cut the top off with a saw , hot knife ,multitool , whatever and add water - possibly with a little sulphuric acid - let it sit for a day off the charge then charge it again for 2 or 3 hours only. Have a good look at it then .

Remember though , your battery is probably done if it gets to this point and you are merely learning about what not to do next time and what not to get next time.
Buy a battery with cells you can get at and top up and maintain properly. Golf cart batteries are my next look at.

Sunking - Thats a great chart and should be stamped on every battery . Most people check the battery ...12.5 Oh thats down a bit, give it 3 or 4 hours on the charger.!

[Guest]

IMG_20161125_082148.jpg IMG_20161125_082118.jpg

Here is one I prepared earlier . It has acid added back and got up to 10.5 volts but would not take any current

[Mike90250]

Open top batteries, I think that's not going to work for me at all.

[littleharbor]

Open top batteries, I think that's not going to work for me at all.

Ditto yours truly. This guy is a mad scientist.

[Guest]

If you think there is a chance to save them , and there always is if you spot the problem early, then drill a 1/2 inch hole in the top and resume normal maintenance . Put rubber bungs in and never buy their rubbish again .

The more people that do that the sooner they change the practice.

Back only 30 years ago you could still have bad cells replaced in larger batteries but I hav'nt seen anyone advertising this service lately as the case construction was changed to all plastic rather than a rubber compound base and a tar based top seal.

[SunEagle]

Open top batteries, I think that's not going to work for me at all.

Something about a watched pot boiling?

[PNjunction]

[ATTACH=CONFIG]n336676[/ATTACH] [ATTACH=CONFIG]n336677[/ATTACH]

Here is one I prepared earlier . It has acid added back and got up to 10.5 volts but would not take any current

Hah - this is a classic waste of time, and the wrong way to go about it.

This is a sealed AGM. They are supposed to appear dry, as all the electrolyte is wicked into the micro-porous separator.

Proper care and understanding are what they need. If abused, ignored, or just used to death, people open the tops, and assume that they are missing electrolyte and add back distilled water, and um, in your case acid. Ugh.

What you have done here is change the dry-charge agm, into a very poorly performing flooded battery with plates exposed to air. Good for getting a bamboo raft off Gilligan's Island, or making restoration videos.

While agm's are not the solution for every application, proper care and application-identification go a long way.

Do you see AGM anywhere on the case ? Look it up . Its a sealed Lead Acid Battery excessively sulphated and boiled dry.
Check before you rant
The example is meant to illustrate what happens when people covercharge such batteries .
The battery is not meant to be used in that condition as anything other than an example . I made that clear . Its dead

That said Remco is a chinese company making a lot of AGM batteries ,in fact most of their range . This one is however not AGM.
AGM is sulphuric acid impregnated into glass matting to hold it between the plates. It still boils off during overcharge and adding water and a little acid will not harm them further . The matting and paste absorbe some of the electrolyte again and often start working again but the sulphation has caused irrepairable damage.

Good for getting a bamboo raft off Gilligan's Island, or making restoration videos

I have no understanding of what that is supposed to mean ? What would a battery have to do with a raft? Indeed what does a retoration video have to do with it ? You speak a strange lingo and are perhaps off with the Fairies. Is dope/pot legal where you live?

[littleharbor]

Quoting PNJunction here,

"Hah - this is a classic waste of time, and the wrong way to go about it".
"This is a sealed AGM. They are supposed to appear dry, as all the electrolyte is wicked into the micro-porous separator."



AGM = Absorbed Glass Matt, 98% saturated, spillproof.
What good is this battery with the diluted, wide open and highly spillable , not to mention dangerous case. This is so bad it goes beyond "What you shouldn't do with a battery"

Do you see AGM anywhere on the case ? Look it up . Its a sealed Lead Acid Battery excessively sulphated and boiled dry.

Do you just follow like a lamb? The example is meant to illustrate what happens when people covercharge such batteries .
The battery is not meant to be used in that condition as anything other than an example . I made that clear . Its dead.
Wake up and maybe try thinking for yourself.

Even with AGM overcharging boils the electrolyte off as hydrogen and oxygen . The paste used is diluted sulphuric acid and that means water! How will you replace the lost water? They are designed to fail.

[jflorey2]

See the white stuff? That's the GM part of AGM. It's supposed to be dry.

[Sun_Bob]

Hi everyone.

Sorry to hijack this thread Phillip.

I don't know how to create a new topic as I am new to this forum.

I need help on my rig.

1) 150 Watts PV
2) 1500 Watts pure sine investor
3) 30 Amp MPPT charge controller
4) 12 V maintenance free Lead Acid 100 mAh battery.

Ok here goes..

I am setting up this setup for an off grid solar for my fish farm. I live in Asia where the sun shines almost 9 hours a day. Currently I am testing out this setup at my home for 2 days straight. I have switched on 2 X 36 watts compact fluorescent tubes from 6pm (when the sun goes down) to simulate actual use at the fish farm and off the lights at about 12 midnight.

Problem:

My inverter goes into standby mode after about 2 hours of switching on the fluorescent lamps (due to low battery voltage) and the charge controller LCD also says the same thing that battery voltage is low of 11.8V. My battery is brand new as well.

My requirement is to use about 200 watts of power from sunset 6pm to 12 midnight.

Can someone please help me out?

Thank you in advance!!!!

[SunEagle]

Sun_Bob

Well were to begin.

Your battery is too small, your panel wattage is too little, your invertor is too big.

Now first you determine what you will be using in watt hours per day.

If it is 200 watts from 6 pm to 12 midnight then it will be 6 hours or 6 x 200 watts = 1200 watt hours.

Your battery will need to be sized for about 4 times that or around 4800 watt hours. At 12volts that comes to about 4800wh / 12 = 400Ah. So that would be either 2 x 6v 400Ah or 3 x 4v 400Ah batteries wired in series. Never wired batteries in parallel. That causes unequal charging and discharging which leads to shortened battery life.

For a 400Ah battery system you will need about 1/10 of that for charging or ~ 40Amps. That calculates to (40Amps x 12volt = 480 watt of solar panels) using a true MPPT CC. Also even though you live in Asia you will never get 9 hours of useful sunlight to charge the battery. Maybe 7 at the equator but never 9.

To keep from wasting that battery you need an inverter that is sized for the battery system. That would be around a 600 watt inverter. If you go bigger you run the chance of over discharging (which I believe you have) your battery.

[Sunking]

TyyTower said: Do you see AGM anywhere on the case ? Look it up . Its a sealed Lead Acid Battery excessively sulphated and boiled dry.

Do you just follow like a lamb?

WTF. Do you know anything about batteries and what a Sealed VRLA Battery is ? Clear as Day printed on the battery it is AGM.

Obviously you are clueless because that is a AGM battery. Please do not answer any questions, you do not have any knowledge off the technology. You do not even know enough to ask a good question.

You are a very cheeky sod. There is no AGM printed on the battery and I have told you it is not an AGM battery so the discussion with you is pointless. I notice you are quite rude to others on here too . Do you claim this forum as your roost do you?

Thats a shame as you will drive the questions away . I don't ask or answer questions to be abused by fools so you can shove it where the sun don't shine Sunshine!

https://en.wikipedia.org/wiki/VRLA_battery

There are three primary types of VRLA batteries, Sealed VR wet cell[citation needed], AGM and Gel. Gel cells add silica dust to the electrolyte, forming a thick putty-like gel. These are sometimes referred to as "silicone batteries". AGM (absorbed glass mat) batteries feature fiberglass mesh between the battery plates which serves to contain the electrolyte. Both designs offer advantages and disadvantages compared to conventional batteries and sealed VR wet cells, as well as each other.

In both other cases it is a water diluted sulphuric acid based electrolyte.

Lets see if you are as quick to appologise.