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Battery gravity doesn’t look good

@chrisski

Yes they do require equalization, The specs for YOUR battery need to be followed, not some generic specs if you want long life.

My battery sets are different enough that they have different specific gravity specs, and different charge specs and with Rolls-Surette, different specific gravity new and when aged in such as over 6 y.o.

My Rolls-Surette set came out the door in july 1995.......still at full capacity, I use the specs for well-broke in as supplied by their engineer example s.g. out the door 1.277 over 6 y.o. 1.260

Yes they do change over time, unfortunately most batteries die long before that due to LOM lack of maintaince

I did a stint at Alaska Husky Battery in Fairbanks, Alaska where we built batteries that had scorching hot 1.320 specific gravity that were suited for the -70 degrees winter temperatures there.......These were “winter only“ batteries as they would cook themselves to death in the summer, Use them like your studded snow tires, put them in the barn for the summer in a cool spot, They would last 3-5 winters but could not survive one summer. I learned just a bit about batteries over the years.
 
Do read the manual for your DC fridge.......they work on a range of voltage and a equalization just might be out of range for the DC controller in the fridge, It would be best if the frig is powered from another source. My Grape Solar DC fridges with the Colku Compressor with electronic drivers will operate on 10-15 volts or 20-30 volts, that requires me to power the frig from alternate source when i equalize a battery set. The electronic drivers can be damaged by eq. voltages......information supplied directly by engineering staff at Grape Solar.....
It’s a 12v/24v dc fridge, manual doesn’t say anything except a low voltage cut out
https://uniqueappliances.com/product/unique-13-0-cu-ft-solar-powered-dc-fridge/
 
The specific gravity tells you about state of charge. Watching the density change over time can also tell us something about state of health.



Parameter errors mean the input violates other settings. See this list which puts them in rising voltage order, or the manual.




It's the voltage being read on the controller's battery output terminals. This can be different than battery voltage if wires are undersized for the length/current. The bigger AN models have voltage sensing wire inputs to get a better read on Vbatt under such conditions.

Measuring battery voltage at the battery with a multimeter would help clear up the question.




What does it look like when a controller tries to EQ an undercharged bank? What mode should show on the controller?

If voltage is still rising I'll guess the controller is trying to drag teh batt up to Veq. If we were doing it manually we'd:

  1. charge fully
  2. then EQ
I had the 30amp version using 8 awg and swapped it out for the 40 amp version. Should I change the wires to 6awg? They are only 3 feet long I checked amperage tables online and it seems that the 8 awg should be alright
 
It’s a 12v/24v dc fridge, manual doesn’t say anything except a low voltage cut out
https://uniqueappliances.com/product/unique-13-0-cu-ft-solar-powered-dc-fridge/
My manual never mentioned it but i got my information from the engineer in charge of the project. He told me directly that the Colku would not tolerate voltage above the limit. There are 2 makers of these........Dutch Danfoss who invented it, found in the very high end units $1500>> example Sundanzer most less expensive units use the Chinese clone Colku, same design permanent magnet motor. same limitations on the controller, its pretty much fatal if you over-voltage it, nobody repairs these
 
My manual never mentioned it but i got my information from the engineer in charge of the project. He told me directly that the Colku would not tolerate voltage above the limit. There are 2 makers of these........Dutch Danfoss who invented it, found in the very high end units $1500>> example Sundanzer most less expensive units use the Chinese clone Colku, same design permanent magnet motor. same limitations on the controller, its pretty much fatal if you over-voltage it, nobody repairs these
They do make the ac to dc adapter I can connect to the inverter instead. That might be a good idea
 
At the price of that unit i would not risk it. This one is a Danfoss powered unit.
 
And is the inverter running off the battery that you are trying to equilaze? 62 watts run time plus inverter effeciency at maybe 80% and 40 watts idle power

There should be no loads on the battery when doing an e.q. it will pull the voltage down too much
 
The adapter will power the frig just fine from a different source of power.........The adapter, inverter, and fridge running is a load on the battery......
 
And is the inverter running off the battery that you are trying to equilaze? 62 watts run time plus inverter effeciency at maybe 80% and 40 watts idle power

There should be no loads on the battery when doing an e.q. it will pull the voltage down too much
Yes it is, so I have to disconnect everything when doing eq, there is no way around this? This system is for my cottage and we have a full fridge
 
The first thing i would do is disconnect all the battery's And put a load test to them separately. You may have full voltage but no or low amps. If that is the case your battery has a bad cell.
 
@Simonbr2

post a shot of the spectrometer for each cell, number them, i will have something to work with
Here is what I have for both batteries, I had to write on the photo to make them, iPhone doesn’t allow much editing of file names. First battery on right has 1a, 1b, 1c and second in left has 2a, 2b, 2c.

before doing this I used a turkey baster and also shook the first battery as best as I could. It seemed to have helped to increase the SG.
The first thing i would do is disconnect all the battery's And put a load test to them separately. You may have full voltage but no or low amps. If that is the case your battery has a bad cell.
The batteries are 6v so I don’t have anything I can test with that. The batteries are also less then a month old
 

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You can get a tester any place they sell auto parts. Harbor freight sells a good one dirt cheep or let the place you got it from check it. Where i worked we sold a lot of batteries and every once in a while you get a bad one.
 
Would it be worth it getting lithium instead? Is there all these issues as well? From what I can find all you have to do is charge using the amperage listed for the particular brand and that’s all.
 
@Simonbr2

Very good, thank you. Now i can tell you that you do not have a dead cell, all cells are within .020 or so .

First off calibrate your spectrometer, very simple, test good quality distilled water, it should be on the water line.

Assuming that your spectrometer is accurate......

This is what is happening.....you are not charging nearly enough for the loads that you have, first thing get some auxillaty power to recharge that pack , keep your loads to a minimum, and apply a steady 40 amps for at least 5 hours, then retest, record results, if s.g. is starting an upward trend, do it again, set the charger to bulk mode, it should stay there. This may well take several days of recovery to see good results.

Do not under any circumstances listen to anyone who says to put epsom salt in a battery.......that is old wife‘s hearsay.
The only thing to add to a Flooded Lead Acid battery is good quality distilled water.....NO not reverse osmosis, OR rainwater, OR filtered water, There are better sellers of distilled water, if in dought go to a major pharmacy and see what they sell.......its widely used in the medical field.....for medical prep, they will not be selling grandamas fififofo water. In California there are Arrowhead Puritas and Calistoga who do it right, anyway, its a bit more expensive.

No dont throw away your investment in those batteries, that is the best lead acid for solar use, you are going to learn that making your own electricity is way more complicated than just buying it from the POCO, if you give up that easily you are in for a nightmare when it comes to lithium, they are technically far more demanding....

Ive said before that i can get more than 20 years on that kind of battery, but that comes with scheduled maintaince. I did state that I have two separate banks of L-16 batteries, one reason is shutdown and service time. I use large marine switches (Blue Seas) to isolate systems for service. You might consider having a backup set. The common GC-2 golf cart battery is built to the same standards as the L-16 traction batteries and will work well is parallel, its not ideal but you should have a standby just in case
 
Rereading what has been said, you allready have the best tester that there is. there is no electrical tester that can tell you more than a spectrometer........the only other thing that you should have is a decent digital volt meter. There are many on the market I just cant recommend any particular one , i do know that Fluke has an awesome reputation for having a meter that retains its accuracy for a very long time. I have bought used Fluke 77 for $40 on ebay and it was in calibration....4 digit display minimum i.e. 12.67 volts...the Tracer is +-20% accuracy Fluke 77 is +-2% at worst case, probably better than .5% No sense measuring something with something that cant tell you what it is!

Harbor Freight accuracy +-30%.......
 
LOAD TEST the battery with a carbon pile I have had the acid test pass the gravity test and showed good voltage until you put a full load on it.





lo
 
The load test has already been done with the load......no further load testing needs be done........the batteries are very low on charge......PERIOD.....charge the battery.....there is nothing else that you can do at this point.......
 
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