Solar Charge Issue

[bobsallyh]

I need some help from the solar experts on here. I installed the system 6 1/2 years ago, hooked it up and it has worked perfectly until the last month or so. 380 watts of panels with a positive and negative lead from each panel to the combiner box and a positive and negative cable to the controller.  Four Trojan T-105 6 volt gc batteries. These batteries were purchased in April 2013. They are wired series/parallel for 12 volt. Blue Sky Controller with IPN Pro Remote. Magnum 2000 Pure Sine Wave Inverter/Charger with remote.

Unless it was cloudy, the batteries would fully charge by 1-2 PM. Then the controller would go the float charge.  Usually the controller would show 90-92 percent in the AM. The only draw would be the eyebrow lights and controller on 2 refers, propane alarm, booster on TV antenna that are on all the time. We have all LED bulbs and really don't use much light. The inverter gets used very little and until recently the batteries would show little discharge with use. But lately, the discharge is considerable.  During the day when the sun is good, the Blue Sky will get to  between 13.4-13.8, very rarely 14.0. The remote shows 100% charged by 1-2 PM. But as the sun goes down the remote shows the batteries discharging to 12'4/12.3. The last 3 mornings it showed 12.2/12. This AM, it showed 11.7 with the same after dark use. I'm thinking the batteries may be at EOL(end of life) Any help/comments sure would be appreciated.

 

Solar into controller with batteries disconnected at 2PM  19.5 V

Solar into controller with batteries connected  14.76 V

Voltage thru controller without batteries connected 12.8

Voltage thru controller with batteries connected 12.4

[Kirk W]

10 hours ago, bobsallyh said:

I need some help from the solar experts on here. I installed the system 6 1/2 years ago,

I am not heavy on solar technology, but I do have 40 years of history working with batteries and they would be what I look at first. Batteries do not usually fail suddenly but just like people the slowly lose some of their abilitys and as age increases so to does the rate of loss. If you check your batteries with a hydrometer on a regular basis you can see this begining to happen. Even if you have not been doing so, compairing current hydrometer readings to those from the battery manufacturer's chart will give you a good ideal of their condition. 

[oldjohnt]

Great question and good specs Bob, I'm NOT any solar expert you asked for but an old long retired and rusty electrical engineer and RV owner of 49 years so will offer my non expert "opinions".

1) While subject to the batteries use and care over six years they should still be in at least "decent condition" but its impossible to say what use and care they have been subjected to. How often or how long they may have sat in lower charge states (especially if over 50%), if they were properly "equalized" on any regular basis, if water level was maintained, how many actual "life cycles" were consumed all contribute to their life, but I'm sure you're already aware of all that.

2) Have you and if not the first thing (oops second after checking water level) I would do is subject them to a full blown EQUALIZATION as called for on the Trojan website. That can reduce the effects of sulfation which reduces a batteries energy storage capacity. I know many smart chargers have a so called "equalization" cycle but I don't consider that to be the same quality and duration of a full blown equalization as specified on the Trojan website. Hey it shouldn't hurt and may reduce sulfation and help the batteries, so why not give it a try if you haven't already???  

3) The easy simple procedure of running a Load Test on each battery coupled with accurate hydrometer readings can help diagnose a problem ESPECIALY with ONE of the four batteries. As you know in that series parallel arrangement even if ONLY ONE of your four batteries is defective it can drag down the entire array. Maybe you only have ONE battery that's the problem !!!!!!!!!!!!

4) When batteries are configured in series parallel if not done properly some of the batteries may do the bulk of the work and age faster then the others so you might want to look at your wiring after considering the experiments performed by smart gauge  http://www.smartgauge.co.uk/batt_con.html

5) While voltage readings can provide an indication of the batteries SOC, voltage sag under load or voltage rise under charge must be considered. Its the voltage at rest and stabilized that also matters. A full true battery monitor system provides more accurate information, but still from your post it appears there is some problem.   

I make no comment as to the quality or effectiveness or your Inverter/Charger or Solar Charge Controller and if it (if any) is a factor in your problem.  

SUMMARY, sure the batteries may be approaching EOL (subject to past six years care and use) but before I ran out and replaced them I would individually one by one take voltage readings at rest and stabilized plus hydrometer readings and run a full blown equalization cycle and then see what happens ?????????????? If not already if they are configured per the above give them plenty of time being charged with your Magnum also. I wouldn't be surprised if there were some degree of improvement (if none of the four are bad) even if not like new. In the event you're ready for an upgrade take a look at AGM technology (Full River, Lifeline, Renogy, Trojan etc) I recently replaced four Six Volt Trojans with three Renogy 12 Volt Deep Cycle AGM's (plus increasing solar to 1080 watts) and am very satisfied with less maintenance yayyyyyyyy

 

 Best wishes

John T  

[NDBirdman]

2 hours ago, oldjohnt said:

4) When batteries are configured in series parallel if not done properly some of the batteries may do the bulk of the work and age faster then the others so you might want to look at your wiring after considering the experiments performed by smart gauge  http://www.smartgauge.co.uk/batt_con.html

Thank-you for that link!  Makes sense and will help me when I set up a separate bank to run both our CPAPs separately from the house battery.

[oldjohnt]

2 hours ago, NDBirdman said:

Thank-you for that link!  Makes sense and will help me when I set up a separate bank to run both our CPAPs separately from the house battery.

 Yo Birdman, Your welcome, when I first studied it I was surprised how much difference connections could make as far as load and charge balance in multiple battery configurations. I run an extra 120 VAC compressor fridge 24/7 and a CPAP each night and a Kill A Watt meter showed my CPAP consumed around 20 Amp Hours each night (depends on Temp and Humidity and Air Pressure settings) and the fridge around 45 Amp Hours per day. LED lights and occasional water pump and vent fans don't require much but if the furnace has to run often at night that's something like 7 amp hours per hour of run time. If a CPAP or other device were to run at 12 VDC versus 120 VAC that saves Inverter inefficiency losses.  If you ran two CPAP's each night and they used what mine does that would require 40 Amp Hours of stored energy meaning if your house batteries were full charged when the CPAP started you would need at least 100 Amp Hours of battery capacity so you don't discharge more then 50%. However lights and vent fans and water pumps and small electronics prior to bedtime after solar quits producing might stretch an only 100 Amp Hour battery bank. Now if a person had say two Trojan T-105 six volts in series that would be 225 Amp Hours and would run those two CPAP's.

Nice chatting with you, best wishes

John T

[hemsteadc]

Solar panels don't last forever. Visually inspect each one for yellow marks behind the glass and burned black spots on the back. Test each one for proper output.

A bad panel in parallel won't show any voltage drop at the controller as series will, but the controller will show an amperage drop. I didn't see any mention of amperage in your post.  That needs to be checked at the controller input.

[Kirk W]

7 hours ago, hemsteadc said:

A bad panel in parallel won't show any voltage drop at the controller as series will, but the controller will show an amperage drop. I didn't see any mention of amperage in your post.  That needs to be checked at the controller input.

Great point that probably should have occured to us non-solar people.

[oldjohnt]

19 hours ago, hemsteadc said:

A bad panel in parallel won't show any voltage drop at the controller as series will, but the controller will show an amperage drop.

If, depending on my panels placement on the RV roof (I have four on a 29 ft Class C) there is a chance one might be shaded more then another, I prefer parallel versus series connection in that situation.....

Hard to say sitting here with no more data or specs if the OP has a battery or a panel problem, but if he is full charged 100% (reducing a weak panel issue once he finally achieves 100% SOC provided the panels aren't allowing reverse discharge) at a certain time but then he is experiencing faster  discharges then previously given the same loads, the batteries (along with connection or short problems) may be suspect. I'm sure he will figure it out if he performs some troubleshooting.

Nice chatting with you, take care now

John T  

[hemsteadc]

 I'm getting the best wattage I've ever seen from my 835 watts of 6 panels:  728 watts!  I'm at 7700' elev, Mesa Verde National park, high noon, clear blue sky, sun is  almost directly overhead.   Sweet.

[oldjohnt]

49 minutes ago, hemsteadc said:

 I'm getting the best wattage I've ever seen from my 835 watts of 6 panels:  728 watts!  I'm at 7700' elev, Mesa Verde National park, high noon, clear blue sky, sun is  almost directly overhead.   Sweet.

That's one good harvest like 87% !!!!!!!!!!!!!!!!! Sweet is right CONGRATULATIONS.  I'm seldom at such ideal conditions, in Texas or Florida in the winter I wont get such yield from my four panel 1080 Watt array, I will be lucky to  get 800 watts probably.  But hey so long as I achieve 100% SOC by early to mid morning (later if rain or parked under total shade canopy) what do I care lol 

Gotta love plenty of solar

John T

[Al F]

On 6/13/2019 at 4:58 AM, Kirk W said:

I am not heavy on solar technology, but I do have 40 years of history working with batteries and they would be what I look at first. Batteries do not usually fail suddenly but just like people the slowly lose some of their abilitys and as age increases so to does the rate of loss. If you check your batteries with a hydrometer on a regular basis you can see this begining to happen. Even if you have not been doing so, compairing current hydrometer readings to those from the battery manufacturer's chart will give you a good ideal of their condition. 

To the OP.  The quickest and simplest check is just what Kirk suggested.  Use a good hydrometer, one with a float showing the specific gravity and has a chart to compensate for temperature. 

Preferably check when you believe the batteries are fully charged.  However one of the key things is to look for at any level of charge is any cell which is quite a bit different in specific gravity reading from the others.  That usually means a bad cell.  

[oldjohnt]

Yo Al, in my arsenal I have THREE DEVICES I use for testing batteries:  1) A Hydrometer,  2) A Load Tester, and 3) A good Voltmeter I use to check voltage of a battery at rest and stabilized.  With ALL THREE of those PLUS eyesight to look for low cells or any gray or milky colored individual cells a person can pretty much tell if there's a problem. Often I've seen one cell go bad which drags down the whole battery of course grrrrrrrrrrrrrrrr 

The reason I use and would recommend ALL THREE DEVICES (Hydrometer, Volt Meter, Load Tester) to test batteries is a Volt Meter and Hydrometer (specific gravity check) can be indicators of the "state of charge" and there might not be any obvious bad cells and a battery might pass hydrometer checks and indicate charged HOWEVER when a load is applied sulfation or other problems can cause diminished capacity AND THATS THE PROBLEM THE OP IS FACING. Sure any bad cells in the array can be found using ones eyes or a hydrometer and that can reduce operation and is indeed a necessary test, but I suggest following those with a load test. A full blown Equalization may help improve capacity but due to past care and maintenance his batteries might pass voltage and specific gravity checks yet still exhibit reduced capacity.  I think that's right ???????????????? Hey I'm rusty as an old nail on this being longggggggggggg retired from practice and this may well be "wrong as rain" and if so hopefully a battery expert can enlighten all of us, but its what I recall NO WARRANTY 

I forget where you're at in Florida, do you ever get to the Florida Flywheelers ?? I spend part of the winter in the Sebring and Avon Park area, lets meet up next winter.

John T    

[Al F]

15 hours ago, oldjohnt said:

 

I forget where you're at in Florida, do you ever get to the Florida Flywheelers ?? I spend part of the winter in the Sebring and Avon Park area, lets meet up next winter.

John T    

That would be great to meet up.  However we haven't been to Florida in a number of years.  Not sure when we will get to that  part of the country again.  

[Mikec557]

I really hate it when I miss out on the ending to a good mystery. Bob, what was the result of your further investigation? 

[bobsallyh]

Edited

[Al F]

17 hours ago, bobsallyh said:

Edited

Did you intend to delete most everything when you edited your post?