Battery bank draining fast

[morton.bia]

Hi guys, to start off I'm gonna say this was our first attempt at solar and after learning about it seems to be totally janky. I bought a kit off Amazon for 1400w and proceeded to hack the system together based o. Those japanglish instructions. Please help me get this fixed.

I have 10 panels at 100w each wired in 5 strings of 2. Then I have a morning star 60a pwm charge controller for that connected to 10 batteries (again 5 strings of 2) 12v 950cca high cycle. Then I have a go power 3kw 24v inverter going to the house.

theres also a 400w wind turbine connected to missouri wind and solar equipment (rectifier, pwm charge controller, relay, dump charge)

Then have a generator running a car charger that charges 24v at 30a when needed.

the wind turbine is a new addition and battery time has dropped off a cliff since I added that. I went ahead and unplugged it to make sure the dump load wasnt kicking in by accident but it didnt improve battery time at all.

as far as loads we normally have somewhere from 200w to 400w loads 24/7.

[Sunking]

I have 10 panels at 100w each wired in 5 strings of 2. Then I have a morning star 60a pwm charge controller for that connected to 10 batteries (again 5 strings of 2) 12v 950cca high cycle. Then I have a go power 3kw 24v inverter going to the house. as far as loads we normally have somewhere from 200w to 400w loads 24/7.

Well you will not like anything anyone has to say especially me because I pull no punches. Your system is doing exactly what you designed it to do, FAIL. So what is the problem?

So you have 1000 watts of panels configured for 24 volts with a cheap PWM controller which turns your panels into 600 watts. With less than 3 Sun Hours this time of year and taking into consideration charge efficiency of the batteries and system you only generate at best 1.5 Kwh per day if you are lucky. Think of it like this, your job only pays you $150 per day.

Next up you use 300 watts on average 24 hours per day = 7.2 Kwh per day. Think of it it cost you $720 per day to live, and your job only pays $150 per day. You are bankrupt and SOL.

This part you will really like. You have 10 batteries of unknown capacity. 950 CCa tells us you have car batteries which cannot be used for deep cycle. They are not made for deep cycle applications. If you try like you have done will destroy them like you have done. Compound that major blunder, and over discharging th ecrap out of them every day, you have destroyed them rather quickly.

You got exactly what you asked for and designed it to do. You pretty much need to replace everything, except the panels. Using 7 Kwh per day in the state of Misery will require a 3500 wat panel system, a 80 Amp MPPT Controller, and a huge 2000 pound $5000 48 volt 700 AH battery. That is what it takes to do what you want.

Good luck with that, and Merry Christmas.

[SunEagle]

Hi guys, to start off I'm gonna say this was our first attempt at solar and after learning about it seems to be totally janky. I bought a kit off Amazon for 1400w and proceeded to hack the system together based o. Those japanglish instructions. Please help me get this fixed.

I have 10 panels at 100w each wired in 5 strings of 2. Then I have a morning star 60a pwm charge controller for that connected to 10 batteries (again 5 strings of 2) 12v 950cca high cycle. Then I have a go power 3kw 24v inverter going to the house.

theres also a 400w wind turbine connected to missouri wind and solar equipment (rectifier, pwm charge controller, relay, dump charge)

Then have a generator running a car charger that charges 24v at 30a when needed.

the wind turbine is a new addition and battery time has dropped off a cliff since I added that. I went ahead and unplugged it to make sure the dump load wasnt kicking in by accident but it didnt improve battery time at all.

as far as loads we normally have somewhere from 200w to 400w loads 24/7.

Where to start???

You have a PWM CC which will rob your of at least 33% of your panel wattage.

You have 5 parallel wired strings of batteries which is a guarantee you will get uneven charging and discharging thus killing of one or more batteries.

More than likely the CC for the wind turbine is not compatible with the solar CC and might be fighting it which will hurt the ability to properly charge your batteries.

Finally you have an average 7.2kWh usage (300w x 24h = 7200wh) which means your battery system needs to be about 5 times that (or about 1500Ah at 24V) to keep you from discharging them too much.

Should I go on?

[morton.bia]

Sunking and suneagle, thank you so much for replies. I knew before I posted my system was junk and I didnt post here to get sugar coated lol. And thank you for confirming the pwm cc sucks which is what I told everyone but was told that quality pwm would be better than chinese mppt. Now that weve established that my system sucks... what can I do to fix it in steps? Remove wind and get new batteries to start? I was told that they would act as independent systems and not fight each other which my small background with electronics good me was wrong but being my first system... what do I know?

sunking I have read some of your posts and I can see why some ppl might not like your style of pull no punches but I actually want to learn and you seem to know a lot. You dont learn how to fight if you never get hit

[morton.bia]

Also I have a 60a mppt chinese charge controller which we replaced with the pwm. Should I put it back?

[SunEagle]

You first need a 60amp MPPT type CC which should convert your 1400 watts to about 58 charging amps.

Now with 58 charging amps you can safely charge a 24volt battery system between 500Ah and 700Ah. Unfortunately with only a 700Ah 24V system you can safely get out of it daily about 4200 watt hour (24V x 700Ah x 25% = 4200wh) which is about 200 watts for 24hours and below your needs.

If you really need that 7.2kWh you will have to increase your panel wattage and battery bank. Since you have maxed out that 60amp MPPT CC you need to go to an 80Amp unit or go to a 48volt battery system. Otherwise you will need to find a way to use less watt hours then you currently estimate.

[morton.bia]

Any suggestions on batteries, cc and inverter?

also can I use my chinese mppt cc with the panels I have now and get away with just grabbing new batteries for a month or 2? I'd wire them for 24v until I save more money for the bigger cc and inverter and then a couple more months get more panels?

[Sunking]

what can I do to fix it in steps? Remove wind and get new batteries to start? I was told that they would act as independent systems and not fight each other which my small background with electronics good me was wrong but being my first system... what do I know?

Hate to say it but start over. Nothing you have was designed to do what you want. The very first step in any off-grid battery design is to determine how many watt hours you need in a day. Everything is designed from that number, your location, and local conditions.

7.2 Kwh per day is a HUGE expensive number for an Off-Grid system. Immediately it demands a 48 volt battery system using 4 or 6-volt batteries each weighing around 250 to 300 pounds each, and costing $700 to $800 each and you would need 4 to 12 of them depending if they are 4 or 6 volt batteries. Additionally you get to replace them every few years at higher cost next time around. Your batteries are completely unusable, and you do not have enough of them. They are a total loss.

News does not get much better. You bought expensive 12 volt battery panels, 10 of them right? Well hate to tell you would need at least 20 more of them. and would be a nightmare to configure. They are just not made to do what you want. It would be less expensive to take your losses, and buy new Grid Tied Panels as you are going to need at least 3000 to 3200 watts total. Using say 250 watt panels would require 12 of them and they would cost around $3000 to $4000. 20 more of the 100 watt panels would cost you twice that plus all the hardware and wiring nightmare to make 30 stinking panels work.

Your charge controller could not be used period, nor can your 24 volt Inverter be used.

Sorry but you have a total loss on your hands, and would be less expensive to take your losses and start over.

sunking I have read some of your posts and I can see why some ppl might not like your style of pull no punches but I actually want to learn and you seem to know a lot. You dont learn how to fight if you never get hit

I am 1/2 breed Indian, I use to get the crap kicked out of me and and learned how to fight back. Us Injuns learned not to get mad and riot, or scream racism. We got educated and learned to get even, take your money and land away, and cheat you out of money in our Casinos, Resorts, Gasoline/Tobacco Stations. We cheat you out of your money and land like you did us and local authorities cannot lay a hand on us. We are sovereign in your back yard.

But thanks, I do try to help people when I can. Lot of folks come here to just to find me and help them. Drives some people crazy and I like it.

[morton.bia]

Ok so I have a meter hooked up and checked the history for the last 4 days. Says I used about 2600wh on average. Looks like my 300w is reduced significantly at night does that make it easier to design? Do I still need to go 48v? I'm hoping to get batteries to move in the right direction and then switch parts of it out. Which batteries should I get? (Tired of doing research and getting the wrong parts >.< )

[Mike90250]

First, your batteries are toast, they are automotive starter batteries, not deep cycle batteries.

2nd You have a 3Kw inverter. Do you have a big, 2Kw load ? Well pump ? I'd say your inverter is way too large, and it's self-consumption is as much as your loads consume

How to recover and proceed.
Be sure what your daily loads are (and nightly loads) Do you have a fridge ? Be glad you did an actual test of your load, and didn't build up a system to handle 7kwh daily, if you only need 3kwh.

Get a genuine MPPT controller. There are many fakes and poor implementation of MPPT. Stick with a major brand Schneider, Morningstar, Midnight, outback

Batteries I'll strongly suggest Golf Cart 6v batteries. Cheap. abuse them and get 1 year, baby them and get 4 years. Learn from them and then you will be able to design the next bank after that.

Base your inverter on your loads. If you don't need 3kw of inverter, just get one that is sized to your loads. If you have to buy a new inverter of the right size, convert the system to 48V.

[Sunking]

Ok so I have a meter hooked up and checked the history for the last 4 days. Says I used about 2600wh on average. Looks like my 300w is reduced significantly at night does that make it easier to design? Do I still need to go 48v? I'm hoping to get batteries to move in the right direction and then switch parts of it out. Which batteries should I get? (Tired of doing research and getting the wrong parts >.< )

OK now we are getting somewhere reasonable. At 2.6 Kwh-day is doable and would require a 24 volt 540 AH battery with at least a 1400 watt panel system with a 60-Amp MPPT Controller.

What is your location?
Does the panel system have any shade issues from Dawn to Dusk?

If you can tell me that, I can give better answers.

Based on your last statement, be careful what you ask for, we can fixya. I can tell you right now at a minimum will require new batteries and controller. You are looking at something like 4 x 6-Volt 550 AH batteries, and I would highly suggest a good high quality 80-Amp MPPT Controller to allow you some room for growth. At 60-amps and 1400 watts is maxed out. The batteries will cost roughly $800 each ($3200 total), and another $600 for the controller. Depending on location at least 2 more panels. Be prepared to spend $5000.

I know that is not what you want to hear, but that is the reality. Here is the kind of battery you are looking for. It does not have to be the Rolls 6-CS-17P but does need to be a 6-volt 500 to 550 AH battery and will take 4 of them wired in series to get you 24 volts. Understand? The batteries and controller you have now are a lost cause. Sell the controller when said and done to minimize loss. Batteries are boat anchors and only worth salvage price.

God Bless and Merry Christmas.

[morton.bia]

I'm in nevada. I dont see any problems with panels Location but hubby wakes up earlier and said the house shades them very early in the morning for about 2 hours since the angle is so low... they are like 50ft from the house and it's a low house >.< we are gonna move them this coming year so that doesnt happen next winter

[morton.bia]

Sunking would you not use the chinese mppt one at all? Or would it still be better than the pwm?
it's this one from Amazon PowMr MPPT Charge Controller 60 amp 48V 36V 24V 12V Auto - Max 190VDC Input LCD Backlight Solar Charge for Vented Sealed Gel NiCd Lithium Battery【Software Update Version】(MPPT-60A) https://www.amazon.com/dp/B0719PGGBS..._DJudCb6088ENM

[SunEagle]

Sunking would you not use the chinese mppt one at all? Or would it still be better than the pwm?
it's this one from Amazon PowMr MPPT Charge Controller 60 amp 48V 36V 24V 12V Auto - Max 190VDC Input LCD Backlight Solar Charge for Vented Sealed Gel NiCd Lithium Battery【Software Update Version】(MPPT-60A) https://www.amazon.com/dp/B0719PGGBS..._DJudCb6088ENM

More than likely that MPPT is fake and really is a PWM type. Unfortunately most of the cheap MPPT CC's are fake but people are still allowed to sell them even if they don't perform as specified.

[morton.bia]

Well i guess i know where my tax return is going this year lol thanks for the help!
any recommendations for a good mppt cc with wind support? I'll get 4 more panels so 1400wsolat +400w wind