Most reacted posts

If it were mine 53.6 to 54

There is a difference between "bloated" and slightly not flat. If you put a steel ruler across the face of most of the cells we receive, most of them are not perfectly flat. Most of them have a slight bulging where the anode and cathode rolls exist inside the aluminum case. Particularly when...

Many years ago I installed a manual transfer switch to work with a portable gas generator for power outages. Lights, fridge, freezer, TVs, pellet stove... Like someone above, power company tree trimming and relocation of a feeder to my neighborhood meant that the generator was rarely needed...

With these panels I would go 5s2p. Or get 18, 5s3p and hook the extra 3 up serial to a separate scc. I think you would have problems early and late in the season.

If protection turns back on, discharge and set the charger to 13.6.

You don't have to use it. But it would be nice to have available. At $6,000 though, I'd have to think hard about that. To be clear, I'm suggesting do both.

If it reads that, disconnected, with a DVM, it's NOT at 100%

Caveat. I know zero about Mac OS. Have you thought about installing a Windows virtual machine on your Mac?

Jumper the resistor across the breaker. Hold there for about 20 seconds, turn on breaker.

Solar Assistant only reports what is happening. It doesn't control anything. 3280 watts / 28 volts charging voltage= 117 amps of charging current. I doubt your inverter has a 120 amp MPPT built in. Therefore, 1600 watts / 28 volts charging voltage= 57 amps charging current. Check the manual...

Do not do this. Only twist that potentiometer when the power supply is not connected to anything.

Because DC flows through the entire cross section of the bus bar. AC tends to migrate to the surface because of the magnetic effect. Again, search skin effect in conductors. Physics.

Or bench power supply

Have you ever been on a roof? Touched a shingle? What you're saying almost seems silly. You've been given your answer several times in this thread but you just don't want to hear it. No one is putting flexible solar panels on asphalt shingled roofs. Which is why I went to an absurdity like...

You can't balance an individual cell. you can charge it but not balance it to balance requires more than one. Did you adjust the voltage setting on the power supply after connecting it to the battery cell?

If you are going to connect two 12 volt batteries in series for 24volts, make sure whatever you buy CAN be connected in series. Edit- Each has its own BMS and on those circuit boards are FETs and FETs have voltage ratings. I suggest that if you are building a 24 volt system and haven't...

Watts are not 'pushed' from the solar panels. They are 'pulled' by the load. You could connect 10000 watts of panels but the load (air conditioner) will only 'draw' what it needs.

Or loose connection causing it to not charge the same as the others. Easy to check. Free. Do you have a torque wrench?

Correct. Setting 01 determines the basic operational mode and relationship between grid, battery and solar. I suggest you go to watts247.com, look for documents, download the full manual. And then, read it.

I love Solar Assistant. https://solar-assistant.io/.

Yeah... I think if this were my battery I would top balance it again and clean each and every piece of metal connecting to another piece of metal. Battery terminals bus bars balance leads a little isopropyl alcohol on a cotton swab And torque every connection. It almost looks like cell one is...

2nd time you've said that. You seem fragile.

None of those. It is the cells themselves refusing more energy because they are full at that voltage.

And if you connected this balancer at 3.292 and 3.294 volts and left it balanced at that place you probably screwed up the balance worse than it would be. You must first charge the batteries above 3.4 or 3.45 volts to see the discrepancy of the cells from one another. Voltage in relation to...

Do not use 60 volts as a charge voltage. You will overcharge your battery.

Charge to 14 volts. Hold that as absorption voltage for 60 minutes. Battery is now full. Then 13.5 volt float. Balancing happens during absorption. You should avoid allowing the BMS to trip.

Important information for SS batteries.

10 watts / 13.8 volts = 0.72463 amps. Assuming the panel is making rated output. Don't expect much charging.

What you describe is exactly what I did. Long ago I installed a 10 circuit manual transfer switch to accommodate a backup generator. When I built my solar system, I merely inputted it where the generator previously was connected. In my case it allowed me to bring household load circuits onto the...

I wouldn't do anything with them except inspect for shipping damage and voltage. Cells should arrive between 30 and 50% state of charge. ~3.29v. That also happens to be what you store them at.

I am running my residential fridge, separate freezer, and a bunch of other stuff. I put a kill a watt meter on both to see what 24.hour normal use consumption looked like. Fridge was 2.02 kwh and freezer was 1.84 kwh. The first step in the solar process is defining what you intend to power and...

It seems to be working correctly. No BMS, smart or not, does what you describe.

If this truly interests you I think you have your answer. If not, you also have your answer.

Sure. And they end up posting questions like this. I just s don't think serial bms's are good idea. Build the battery for the voltage that you want and put one BMS on it. Just my opinion

Bad assumption. More than one kind of lithium battery in the world.

Perspective. 9 each 255 watt per. One of two arrays. Pointed at 155⁰ and 205⁰. Previously proved with slap together mounts. This is a rebuild.

He meant yep.

I charge to 3.475 (55.6) volts per cell, absorb for 1 hour, and then float at 3.375 (54). Low voltage cutoff to grid at 50v, return to battery at 52 volts.

I got a 4.8v 700ma flashlight bulb, soldered wire to a little switch, to insulated alligator clips. Wires long enough so that only the clips reach across the top of the pack. Works great for fine tuning at the top of the charge while watching BMS voltages.

Don't do it. Paralleling a second pack is an event and should be prepared for. That means charging both packs to the same place before connecting them together. This is the only SAFE way to do it. And i can think of no reasonable purpose of wanting to connect 2 parallel packs of dissimilar SOC.

This takes me about 20 minutes per pack every 6 months or so. Also, when complete, don't forget to put your absorption time back down to 1 hour or whatever suits your fancy.

Why? Don't just drop a bomb like that in the middle of thread not explain yourself

I don't think you need 1.5-2 kw for a home office. Suggest you start a list of power requirements. Buy a kill-o-watt meter and measure each outlet you wish to power for 24 hours. So, for the outlet powering the power strip with your network gear plug the kilowatt meter into the outlet and plug...

This is exactly what I've done. Transfer switch was previously installed for gas gen. Gen input is now connected to solar system. Rate is $0.10/Kwh. Electric bill has gone from $235/month to $75/month. This required 13 months in the final configuration. Use grid as backup.

Exactly. Lots of waaahhh getting into this thread

Cheaper connection. Higher voltage, lower current, less copper.

I too had a few panels not contributing. Leaned them against the fence for an extra 1,2k or so. My winter helpers.

Right When these devices that we're mounting to the wall fail, there's usually a loud bang and a bit of smoke but they don't sit there smoldering at 200° c for hours

Lazy? Offensive. I have the abilities to develop my own system. I don't know what your time is worth but my time is worth at least 30 or $40 an hour and to develop something as Folsom and robust as solar assistant would take several hundred hours. For less than $200 I have a very fulsome robust...

Why not send SA this question directly? I, too, think it will work just fine. SA reports on each device connected to the Rpi.

T This. There is nothing wrong with the BMS

Irrelevant. They are typically shipped at 30% SOC. You probably should have performed a parallel top balance on them before commissioning. At minimum, you need to charge the battery. Battery will tell you when it's full, it will stop taking current. At a charge voltage of 3.5 volts per cell. I...

I've said this before and I'll say it again. No cell manufacturer is making 320 amp hour cells and no reputable reseller is selling 320 amp hour cells.

Wrong. 80 amps is the maximum output current. Charge current. Like the subsequent poster says current is drawn by the loads. The charge controller will only draw up to its maximum capability. 18 amps. Anything above that power from the array gets clipped. This issue is a good argument for...

Nope. Can't parallel these two into a single MPPT. Separate chargers.

I too have pair of 3K inverters. Whenever one of mine sees a peak in excess of its capacity, I see a bit of grid assist for the duration of the peak. Nothing goes into overload and nothing trips. My normal base load though is lower than his. We are careful not to try and make heat on more than...

The manual transfer switches don't get switched back and forth. They are now set to generator / solar and those 10 circuits run that way 24/7. In my main breaker box is a double pole 30 amp breaker. That breaker feeds AC to both inverters. So now the inverters can choose between solar, battery...

Lol Perhaps it might be a good tool to have around a 12v charger... You know, if you are going to play with 12 volt batteries... Your problem is not the inverter. Nor is it a battery problem per se. You need to charge these two batteries that you have connected in series to the same place. I...

Hmm. 3897 wh / 12.8 v nominal = 304.45 ah. What's the problem?

All in one - $ Separate pieces -$$ Victron -$$$ Sol Ark-$$$$

This is what the absorption time is for. Charge to full (above 3.45 per cell) and hold that voltage for an hour or two. The battery acts as a buffer for your solar so even while solar is adequate from time to time with spikes and load the battery will slightly discharge by an amp and then...

Don't know. I do both simultaneously. Just put 4 hours on the absorption clock to hold 3.5 or 3.55. usually only takes 20 minutes per pack to get under 10 millivolts.

Please put an insulating tubing or heat shrink on your threaded rods.

Settings tab. Scroll down to battery. Click disconnect button. Choose multiple instances of your batteries. Easy.

Except pack 3. 140mv cell delta. For five of the packs that is fine however it will just exacerbate the problem with pack 3. The imbalance in pack 3 is probably causing the BMS to turn it off for high voltage disconnect. And how does one reach more than 100% state of charge? The rest of the...

Actual testing...

I used Temco Industrial for all my 2/0 and awg8 and 10 solar wire. https://temcoindustrial.com/electrical/wire/welding-cable/

What size are the cells? What is the charging voltage of the bench power supply? 1.294 amps for 40 hours is 50ah. 3.37 volts can be anywhere from 50 to 80 % SOC.

4p equals 1208 amp hours. What are the charging specs of your charger? Assume the cells were shipped at 30% state of charge equals 900 amp hours. A 100 amp charger would need 9 hours at 100 amps to fully charge that battery. I don't think your battery is charged.

I agree with qdog. Battery is dead. Focus your attention on a full charge. You need more solar if that is how you want to charge. 170watt panel x.6 (age, degradation, improper aim, clouds) = 100 watts. X 5 hours= 500 watt hours of charging (loads off, inverter disconnected) per day if you're...

Huh?? We are talking about solar generation, right? How exactly does over consumption of solar generated electricity contribute to man-made global warming? Woo... Kinda talking out of a hole that under normal circumstances doesn't produce sound.

You've been given a path to pursue to fix your problem but you seem to just want to argue about semantics. SOC is a derived, calculated number. It is not a direct measurement. To reset the accuracy of this calculation, you need to fully charge your batteries. And hold that charge value for a...

3.38 volts is too early to turn on the balancer. Set your balancer on voltage to your target charge voltage. The cell voltage drops because that cell has not absorbed all the energy that it needs at that voltage. I charge to 56 volts. I then hold that voltage from the charger for 90 minutes...

I am also at this stage. I configured 4 each 12v packs and using a 10 amp supply charged to 3.45. Above about 3.4 each 4 pack had a runner. I didn't let the BMS cut off charging however. I watched carefully and when the runner went above 3.6, i terminated charge and put that 4 pack into...

Yes. In my post

18 A is the max from the solar panels to the MPPT charger. The 60 A is from the charger to the battery

Hook up the generator AC output to the inverter AC input, set inverter max charge to 10 amps, and give it a whirl. It will either work or it won't. But then you will know.

The BMS is your safety device not your operational device. Set up your inverter charger back to grid settings to avoid that low place. Ideally, the BMS never trips.

Only necessary when connecting battery to inverter. How often do you disconnect the battery from the inverter? $2 for a pair of 50 ohm 100 watt ceramic resistors that live in a small ziplock baggie in my toolbox. Easy peasy.

Because the BMS only has one, accurate truth point... It resets/calibrates at 100%. But keep in mind SOC is a derived value, not a direct measurement. If you run your generator to charge these batteries to full, the BMS will read 100%, but ignore that and let the charge continue. Set your...

I use the settings in my charge controllers. I can automate the changing of charge currents through Solar Assistant.

No They discharge (and charge) at different rates. They will both arrive at the same place eventually.

As a general practice I try to only use one hand at a time and as stated above, cover when done

This is incorrect. In series, the voltages add but the amps stay the same. In parallel, the voltages stay the same but the amps add. Therefore, 485w 2s2p = 107 3 volts open ckt, 18 amps max. As previously stated, for your application, 2s2p is a perfect configuration with these panels.

Don't let the BMS shut off the battery. You should configure the inverter to switch over to grid BEFORE reaching the BMS disconnect voltage.

Ensure the settings in your chargers are correct. Ensure the settings in your BMS are correct. There is no inherent condition called "runaway overcharge" ≥> operator error. Those are your insurance.

Inadequate solar 440 ah x 12.8 v = 5632 watthours. 210 watts x 3 = 630 watts x 5 hours = 3150 watthours. On a perfect day with perfectly aimed panels.

Oh hell. If nobody else is going to say it I will. Liquid nails.

15s can work fine IF all the batteries in the pack are 15s. If you are mixing 15s and 16s the combined pack will only operate with the capacity of the 15s. And probably worse than that because the 16s batteries will never fully charge.

+1. You proved to yourself that you got what you paid for. Now stop capacity testing them and put them into production between 3.0v and 3.4v.

Maybe you should investigate it to know what is already in the market...

Did you EVEN LOOK at the pictures?

+1. Disassemble, connect in parallel, apply bench power supply at 3.5v until current drops to zero. Reassemble in series Problem fixed.

And how are you going to add that capability if you're not going to replace the BMS? With a BMS that has Bluetooth capability to give you visibility into the individual cell voltages.

https://www.irs.gov/credits-deductions/residential-clean-energy-credit

2nd mppt charge controller.

So wrong...

Wrong