I have around 12 hours that I use power from the batteries, from around 8. My daylight hours here are long. But if I am right, and this is only what I have learned over the last few days so please correct me) 424ah x 48v should give me 20,345w divided by 2 for 50% discharge leaves 10,172w over 12 hours for 200w output that should be fine?
Urgent help please
- Thread starter Emm
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Okay so my next questions, if the batteries don't improve would be about what would be compatible. The guy I spoke to about a lithium batter told me that it would have limited capabilities with my current inverter. But I guess we can get to that in a couple of days.
Not sure about equalisation. I read not to, that GEL batteries don't require it and then read somewhere else that it should be twice a year. No idea at all what settings I should use if I should do it. I mean, I guess I really don't have much to loose right now. Maybe I should try and figure that out.
Fuse yes.
mikefitz
Solar Wizard
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The rating of the battery is not important .
Fully charged display on the inverter may be misleading.
Check the voltage at the battery compared to the voltage at the charger. Any significant volt drops will confuse the charge process.
The charge voltage of 58.4 needs to be reached at thebattery and held at that value for some time to fully charge the batteries. Under this charge voltage the individual batteries should show almost the same voltage at 7.3 volts, is this the case?
If the charger is dropping to float early, increase the float voltage. If the absorbtion duration, the period at 58.4, is too short, Increase the float voltage, perhaps as high as the charge voltage , for a day or two.
As a last resort consider applying an equalisation charge to the battery string, ( this is normally disabled for GEL).
The panels are showing slight shading from the undergrowth , this will reduce output considerably.
Fully charged display on the inverter may be misleading.
Check the voltage at the battery compared to the voltage at the charger. Any significant volt drops will confuse the charge process.
The charge voltage of 58.4 needs to be reached at thebattery and held at that value for some time to fully charge the batteries. Under this charge voltage the individual batteries should show almost the same voltage at 7.3 volts, is this the case?
If the charger is dropping to float early, increase the float voltage. If the absorbtion duration, the period at 58.4, is too short, Increase the float voltage, perhaps as high as the charge voltage , for a day or two.
As a last resort consider applying an equalisation charge to the battery string, ( this is normally disabled for GEL).
The panels are showing slight shading from the undergrowth , this will reduce output considerably.
Last edited:
Q-Dog
¯\_(ツ)_/¯
Since you are on "User" settings you should check to see if the equalization settings are on or off. For now I would make sure equalization is OFF until we get a better feel for the condition of the batteries.
I would run the new settings for a couple of days and see if MAYBE the batteries are not too damaged and you can still get some more use out of them.
I would run the new settings for a couple of days and see if MAYBE the batteries are not too damaged and you can still get some more use out of them.
If this is the correct manual for your unit ( https://www.masterbattery.es/manuales/Omega_UM-v3.pdf) it would seem you have a wide range of battery types that you can use.
I am not sure. I only just changed the settings. The previous setting had the max charge at 56v and float at 54v they were reading 6.2 at those settings. I will keep checking over the next few days
Yes, that's the one
Will check and make sure now
Hedges
I See Electromagnetic Fields!
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Imbalanced, each battery should be charged individually so full and same SoC. Then can be used as a bank.
Although, even a balanced bank might diverge when fully discharged (5.2V)
Not fully charged. Needs to charge to proper voltage, then hold there (absorption) for some hours.
If you fully charge the batteries offline with a suitable charger (something a battery vendor could do if you don't have a charger), either he could test capacity, or you could put in system, with PV shut off, and measure capacity with a test load. I connected an electric heater to my inverter and measured time to shutdown (by powering a mechanical timer.)
Gel is relatively tolerant of discharge abuse. Might recover with full charge.
There is a maximum charge current the batteries want; avoid exceeding that.
Same size bank as my SunXtender AGM; 405 Ah 48V
10172Wh / 12h = 848W
mikefitz
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Even at the previous setting of 56 volts, ( too low a charge voltage according to battery data) the battery under charge should have reached 7.0 volts for each of the 8 batteries.
56 volts at thecharger and only 6.3 x 8, 50.4 at the battery, suggests unwanted volt drops.
Ideally the batteries should be stored in a cool location, the arrangement in the picture looks very 'casual'.
It seems you are getting poor advice from your local experts, and as you do not have grid power, I assume, an 'all in one' may not be the optimum solution. However, it is what it is, and the Master Power Omega can be set up for any battery type, so no need to consider alternative chargers or inverters at this stage.
If possible a series of voltage measurements, each battery voltage, pack volts at the terminals and charger volt, whilst under charge and load conditions, may assist resolving the issue.
56 volts at thecharger and only 6.3 x 8, 50.4 at the battery, suggests unwanted volt drops.
Ideally the batteries should be stored in a cool location, the arrangement in the picture looks very 'casual'.
It seems you are getting poor advice from your local experts, and as you do not have grid power, I assume, an 'all in one' may not be the optimum solution. However, it is what it is, and the Master Power Omega can be set up for any battery type, so no need to consider alternative chargers or inverters at this stage.
If possible a series of voltage measurements, each battery voltage, pack volts at the terminals and charger volt, whilst under charge and load conditions, may assist resolving the issue.
Can't charge off the system. No grid connection so if I disconnect I have no way to charge offline... Hopefully the new setting might help them recover.
Haha. Yes it probably does look casual. They are set up in a cave. Definitely the coolest place here especially in the summer. The temp stays pretty constant. Okay, I will try and get some more measurements. Probably tomorrow because it's a little overcast now.
Hedges
I See Electromagnetic Fields!
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With system up and batteries charged but unbalanced, you might be able to top off lowest batteries with AC powered 6V charger in-situ.
I've tried, but its a bit problematic because my inverter sees pack voltage rise above setpoint and lets it drift back to correct. You would then have to disconnect charger, see if the low battery settles to same as others.
Manually connecting a DC source like one PV panel to a battery would also charge it. But you'd have to watch voltage. There are plenty of 12V charge controllers. Not so many 6V, except for gadgets like path lights. Mostly PWM or linear, not MPPT switcher, so can't handle a high voltage panel. If you disconnected one panel and opened its junction box, it may have taps which are each 1/3 of panel voltage, better for such use. Or buy a separate panel for individual charging.
PWM, 6V, 3A
Okay, that all sounds a bit complicated but will re read it and see what I can do.
MisterSandals
Participation Medalist
20,345Wh
10,172Wh / 200W = 50.86h
If you use the correct units, the math makes more sense and communication errors avoided. But it sounds like your understanding is correct.
So 12 in series is 36.99Voc = 443.88Voc
MPPT (optimized) range is 120V to 450V
What are the other 2 panels doing? If 14 in series, you could be over max input voltage (bad).
On to charging, i think you will benefit by lowering your charging amps down below 60A.
250W solar x 12? panels = 3000W
10,172Wh / 3000W solar = 3.39h
if you spread this out over 5 hours:
10,172Wh / 5h = 2034W charging
2034W / 58V charging = 35A charging
I would lower your max charge current to 35A to put a slower, deeper charge on your batteries.
Sorry for the incorrect units. I rushed the post to make sure I didn't miss replying.
No I only have 12 in series. The other two are doing nothing.
Okay. That's something I couldn't figure out but will change it now. I haven't seen the charging current go above 30A so far I don't think (struggling to remember all of the numbers I have recently learnt)
Yurtdweller
Solar Enthusiast
I don't have much to add, but I will reiterate what others have said about your panels, with a bit more info. Will Prowse did a video about this, I think, and I frequently watch my systems stats while pulling weeds. My panels also sit on the ground, and can collect pine needles, as well as weed shade. When one tiny part of a panel gets shaded, just a bit, the whole row of cells on that panel is affected, and can decrease panel output by a huge percentage, ten or twenty percent, sometimes. When panels are connected together, all the panels will operate at the stats of the lowest panel. If one panel is decreased by, say, ten percent, your whole array will decrease by ten percent. So, a single bit of shade on a single cell on a single panel can dramatically reduce efficiency. This is an affect that is far from intuitive. It doesn't make sense, initially, until or unless you have a fundamental understanding of all aspects of the functionality of a PV panel, but it is a fact. I'm running 1200 watts of PV into 14kwh of LiFePo4 cells, so I have Bluetooth monitoring of my entire system, and I can instantly see the effects of even a single leaf on my system. If convenient, raise your panels up a few cm on cinder blocks or boards, and keep those weeds trimmed. I hope you get your problem sorted out. As far as your overall issue, please check every battery cell individually, and record voltages. One bad cell, as others have said, can drag your entire system down. If one cell is loosing it's charge early, your voltage will drop to unusable levels very quickly. Check resistance across all battery connections. If humidity is high, you could have invisible corrosion affecting charge and discharge. I've never run 8 cells in series, though, so I can't really offer advice on that particular situation. Good luck.
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