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I don't know how to determine quantitatively, but for a while now my thinking is to go a few degrees less than perpendicular to the sun at noon. The reason being, not every day is sunny. When you have cloudy days it may be better to have your panels at a less steep angle in order to catch...

With those lead acid batteries, try to keep them from dropping below 24v. If they spend appreciable time under 24 volts their lives will be shortened.

Do you have a clamp meter so you can measure current at various places? I gather from that last photo that your load is being powered via AC bypass and that it is charging your battery at 27v but at zero amps. Is your battery shot and just not accepting any amps?

I agree with MichaelK that I would go with a larger inverter than 800 watts. I am powering a 9cu ft and a 7 cu ft chest freezers in my garage using 1000 watts of panels, 24v, 200AH LiFePO4 home brew battery, and 2000 watt pure sine inverter. When one freezer's compressor kicks on my battery's...

Another update. I know some folks have noticed that their EVE 280 Ah cells swell with the charging cycle. Today is a nice sunny day, and my Lishen 202Ah cells charged to 100% capacity this afternoon using my 1kW array, so I opened my battery box (a.k.a. battery ice chest) and examined my...

Is there a consensus that the swelling is caused by a breakdown of electrolyte and that breakdown of electrolyte is correlated with increased voltage? In that case it might be better to set the BMS cutoff voltage to a lower value - 3.4 or 3.45 volts so that the cells never see a higher voltage...

Not that I recommend this, but one way I sped up top balancing was to wire up my battery in its final 8S configuration and charged the pack using a large solar panel. I depended on my BMS to cut off when one cell reached 3.65V. I did watch the individual cell voltages like a hawk once it got...

So far so good. My pack is working well. I have 1kW solar array feeding it, and my load is a deep freezer and grow lights for seedlings for my garden. It is staying well balanced. I'm using the Overkill Solar 8S BMS. This system is in my garage, so the lowest temperature it sees is about 0...

That's a larger 175A connector than the 15, 30, 45A ones that hams generally use. I'm less familiar with them, but I understand that there's a convention for those, too. Since these larger ones are one piece I don't think you have to worry about it - it is marked on the connector. With the...

Exactly where was the charger attached? Did you attach it to the PV inputs of the Victron? Did you clip it to the main terminals of the battery, bypassing the BMS? Could you tell if any of the fuses had blown? What was the make and model of the charger? Was the charger sitting in that...

I use a cheap plastic ice chest, but when the lid is closed there is no ventilation. Also you have to be sure to get extra long terminals if you want to feed them through the thick walls of the ice chest.

I'm a ham radio guy so I am biased towards the Anderson Powerpoles. The 15A, 30A, and 45A sizes are interchangeable with each other - they're just designed for use with different gauge wires. The thing I like about them - you don't have to worry about whether to use a male or female - they're...

Now, of course it is important to either top or bottom balance all cells before assembling and double checking cell voltages before paralleling them to make sure they are very close.

No. Since the batteries are at the same chemistry and are in parallel (and therefore at the exact same voltage) they will have the same S.O.C. in theory. Now, I know there are sometimes deviations between theory and reality, but I wouldn't be afraid to give it a shot. The smaller battery...

I would expect, all other things being equal, same or very similar battery chemistry that the higher capacity cell would have a proportinately lower internal resistance, so higher capacity cells will tend to source more of the current load. As long as the battery + and - terminals are tied...

Ha! So it is good that I built my battery inside a plastic ice chest and put plastic spacers between the cells! I always cringe a little when I see someone build their battery box inside a painted metal case. What happens after years of jostling about when some of the paint or insulation wear...

Sorry, I hadn't logged into the forum for a while. I measured just at 200 AH capacity for my 202AH cells, so I'm happy enough. I know the uncertainty of my measuring equipment is probably greater than the 1% difference. I also stopped my test at 2.7 volts per cell, as I saw that my...

I built my 8S 202AH inside an inexpensive Igloo ice chest with room to spare. An 8S 280AH might also fit, but I haven't measured it out - it would be close. The handles on the sides makes it possible for one moderately strong person to move the battery without assistance. My battery is about...

Seems like crummy pre-loaded parameters. It does charge but only when my battery is below 26.4 volts. Which for LiFePO4 the average cell is 3.3 volts and my battery is only about half full. Then it quits charging! I need to increast the "boost char return voltage" but it won't let me do that...

I can't tell exactly how large these are from the photos, but they could be about the right size to use two of these to charge a good size phone power bank. I bought an empty powerbank case with the electronics and put 8 salvaged 18650 cells inside for a total of about 15000mAH. I charge it up...

I just connected my Renogy Rover 40A Li to my 24V LFP system, and it is not charging. My voltage is above the Boost Char return voltage of 13.2x 2 = 26.4v. Is this normal? Does the voltage have to drop below 26.4 v to start charging?? If that's the case I wish I could change that setting...

I received the new inverter. So far, so good. Proper sine wave output, good 120vac output. Have run a small fridge with it for a few days. Getting ready to plug my deep freezer in.

Photo looking down into my ice chest battery. My cheap ice chest has a flat floor and flat walls. I thought about using an ice chest that has built-in wheels and a handle, but there are irregularities on the inside where the wheels are and makes it more difficult to fit the batteries down...

I built an 8S 24V 202AH LiFePO4 pack inside a 48 quart plastic ice chest. Dirt cheap container. The batteries weigh about 70 lbs, but I can lug it around by myself using the handles. The only difficulty I had was installing the battery terminals through the thick walls of the ice chest. Need...

Yes, there's more than one way to skin a cat. In my first large LiFePO4 battery I had my BMS, solar charge controller, solar panel, but no high current bench power supply. So, I hooked up my battery and BMS in the 8S configuration, hooked up the solar charge controller and solar panel. I...

As you charge you will notice the voltages creep up very slowly at first. But then as they approach 3.35 you'll notice they will creep faster and faster. One or two cells may creep faster than the others and you will really have to watch those more closely because they will finish first...

It depends on the lead acid charger, but I think a lot of the lead acid chargers will use a voltage much higher than recommended. If you could find yourself a constant voltage power supply which can be adjusted to about 3.4 volts for cell, or about13.6 V for a 4S battery, I think that would be...

Abrade the outer layer, then expose the strip to salt water. If it is plated steel it should rust. If it is pure nickel it won't.

I bought some Lishen 202AH cells from an Ebay vendor in July. Internal Resistance spec is more than proportionally higher than the 280 AH Eve cells, but still plenty low for my application. The pack I built is working well for me, no complaints. Of course this is my first LiFePO4 pack build...

Update: The ebay seller has been signing their messages as "Giandel" and it looks like Giandel inverters is all they sell. They might be Giandel's official USA vendor on Ebay. Anyway the latest they sent me after I sent the photos and a photo of the serial number say that there must have been...

I opened it up again and looked inside. Main board is marked "PM-2000KSC" Ver 5. Which I believe is their model number for one of their modified sine inverters. I also found a Youtube Video from Jehu Garcia's review of Giandel's 3000W pure sine inverter and that one has a large inductor and a...

Here's a photo of the inverter.

Well, I did dig up my oscilloscope and discovered that the output waveform looks exactly like a "modified sine wave" inverter waveform, not a pure sinewave inverter waveform. Either my unit is malfunctioning or it is a knock-off, not what it is purported to be!

I'm not sure about my multimeters. I have an expensive Fluke 27 meter and a cheapo Cen-Tech 95683 from Harbor Freight. They both give me the same VAC reading, and from my understanding an averaging meter still gives you an the correct reading *if you have a pure sinewave* which my inverter is...

Still at 104 VAC, and I had a toaster oven running on it all afternoon pulling 600 watts, and it was 104 volts then. . . Past few days have been relatively low humidity. Something else I have noticed, my battery is LiFePO4, and when it is fully charged over 27 volts, the inverter output has...