Rooney Hat

Damn, that's pretty annoying... losing all that afternoon sun. Maybe with some smart timing, I can turn my geyser on for a bit longer and have the last of the afternoon sun get the batteries as close to 100% as possible. Have also set my cutoff to 20%, will see if the low voltage kicks in again tomorrow.

I just upgraded my 4x AGM to 2x US3000c on my Growatt SPF 5000TL HVM. After following the guides (Thanks to everyone who struggled with this and provided the help), I did the following: 1) Created the network cable with pin 1,2 and 3 reversed to 8,7,6 the other side and cut all the rest. 2) Set the ADD to 0001 (reversed, it's pin 1 on, rest off) 3) Left the slave battery on ADD 0000 and connected it to master with a straight cable. 4) Set the Back to Utility to 10% (I am assuming with the 95% DOD I can safely set this to 5%) 5) Set the Back to Battery at 95% (Going to fiddle with this number so I can use solar to power load and charge at the same time instead of using mains to power load while the solar charges to 95%) Everything appears to be working except two things 1) Every morning when my batteries drop below 10%, the Inverter powers off after around 5 mins of low voltage warning instead of switching back to utility. (I found some Pylontech US3000c guide stating that on Growatt SPF 5000TL you must not set back to mains below 20% as it will cause a low voltage warning, but I lost the link to that guide to make 100% sure) If that is correct, that means I can't really take advantage of the 95% DOD of these new batteries, and that sucks. 2) Since being on these batteries, there is something odd happening in the afternoon where it charges the batteries to 100%, then puts all load on the batteries and ignores the solar completely. Have no idea what could be causing this. I am on SBU with OSO charging. Anyone else getting these issues?

Absolutely something to consider, But would have to pay around 40k to get to 8.something kwh 80% DOD in Lithium, or just spend 20k to double AGM capacity from 4 to 8 200ah. getting me a total of 19.6 (9.8kwh with 50% DOD) with the idea that I wouldn't use that amount every night thus extending the battery life of all. Provided they don't fail me.

Haha yup, definitely doing the weight training. If I knew then what I know now, would have given the AGMs a skip. Though for capacity sakes because I already have 4, I could consider doubling down and getting 4x extra 200ah batteries would give me about 9kwh @ 50% DOD... provided they stop becoming duds. This would push me through the night, but introduces the 3kw load the geyser has at 5-6am Much to consider! Just got confirmation that they swapping out for new battery today. So I'll see how it goes!

Thanks, totally appreciate it! As you said, people just throw more capacity and don't consider what kind of loads are intended for the batteries and how it hurts these new affordable batteries that everyone jumps on. My original plan was to get the AGM and upgrade to lithium in a few years when they are cheaper. But I get the feeling that's biting me in the ass now.

Totally agree, I started from scratch during lockdown and did everything myself with 0 knowledge, If it wasn't for the guys on this forum, I'd be lost

Calculated at my current usage, they should be nowhere near their end of life. 1) Batteries are not in a confined space and have good breathing room. So I don't think they go above 25 degrees, might go a bit over in summer. 2) I only discharge to standing 48/49v, should be roughly 50%, rough calculations should get me at least 3 years of life. 3) Charge and Float v are on the within the safe values for the batteries. On an average day, they will only discharge to 50% once at night and might have a bit off usage during the day to offset Solar. (And I know I asked about the 4kw load, I don't think my batteries have ever had to do that kind of heavy lifting due to the times I set for the geyser. I think the most they get hit with is 2kw from the kettles at night.) The faulty battery is getting replaced though, So all batteries will be in working order. I asked around about my problem and someone recommended a balancer, and after looking into the HA4, sounds like a very useful thing to have and should extend the life After I bought the system, After 2/3 months I noticed something was off and It took me a while to figure out the issue was one of the batteries because the inverter was balancing the voltages while charging, only picked up that 1 battery's voltage was 1/2v off when I disconnected the batteries from the inverter after they had been discharged a bit. Then a month later, discovered the brand new battery and one of the older ones had the same issue. and then last month again another one down. Can't figure out what it is, so I have re-crimped all my cables and ordered the balancer now. When the replacement gets back, I guess I'll see how long it lasts.

Thanks, this is very good to know! Makes a lot more sense. I am not a fan of the voltage measurements of the AGM to determine battery %, but the safe zone is that 50% is a little under 49v, so I have it set to a cut off of 47v (As the load drops voltage by 1/2) Then it settles back up at 49%.

You Legend, thanks! Yup, totally agree, hate hitting batteries with heavy loads. They just offset what solar can't carry during the day 12pm to 2pm, So unless we have 0 sun, and the batteries have somehow gotten back up at 54v, it will use Eskom on those days. Just wanted to be sure because I am having issues with my AGM batteries, 4 faulty in the past year. (Voltage off causing the combined voltages to drop) Just re-crimped all my cables again, confirmed equal cable length and have ordered a HA02 battery balancer. So hopefully it doesn't happen again... getting tired of lugging these 60kg batteries back to the supplier.

Oh the geyser is just going through the main DB with a timer, I have everything on the DB going through the Inverter, but have downscaled the geyser to a 3kw so that I have just enough Solar to power the geyser without hitting the batteries during a perfect day. If the inverter overloads (Someone turns on a kettle etc), it cuts over to Eskom. I'm looking into smart connections to avoid that, but because my Interter is Growatt, I'm having a hard time getting live readings that can translate to Home Assistant.

This might be a stupid question because my math sucks, I am thinking about getting 4 of these Mecer 200ah units to replace my existing 4x 200ah AGMs with a 5KW Growatt inverter. What is the maximum load these batteries can handle? lets say it's overcast and I have 100% battery capacity, could these handle a 4kWh load from the geyser for an hour? And another question while I am thinking about it, can my AGMs handle that kind of load without causing damage?

Thanks Guys, Got the plumber to do the install, I'll test how much the temps between tap and ambient geyser differ, and if it's isn't a major difference, I can always add a small 1kw element to the old geyser that can be used with excess solar.

That's true, it's a pretty old square geyser and I think it's losing a lot of heat overnight. I've ordered a Geyserwise kit, and I could probably use it to check how that temp differs to the tap water temp, especially in winter.

Hi Guys! I've got an older 200L geyser in the roof and have decided to get a newer 150L 3Kw to go easier on my solar during the day. An Idea I had was to feed the old geyser into the new geyser purely to use the ambient temp in the roof so that the water feeding into the new geyser isn't as cold. Not sure if it's viable though, but I will have the piping done so I can cut out the old geyser if required for any reason. Just wanted to see if it's a worthy idea!

Well I'm on AGM batteries, and since I installed the unit in May, the Battery voltages dropping way too quickly now and has been getting progressively worse. Running 500.08/002.03 9.6KWh AGM dropping to 48v standing (46v safety trigger under load) in less than 2 hours at around 200w-500w draw, should be getting at least 6 hours till it gets to 48v Charging also seems go climb way too quick, going from 48v - 49v then to 52+v in less than 5 mins while solar charging at 400w still early in the morning... I have only ever dropped the batteries past 50% twice, once during load shedding the last time we had, and the other night during a power out. But the issue existed before that, and I noticed when the voltages dropped to v46, it slowed down the drain considerably, holding 45.5v for over an hour at the same 200w-500w draw. The tech from the company I purchased the unit says there is nothing wrong with the batteries, all tested at within .1 voltage of each other during load and standing. But I question if he knows what he is talking about, because when he finally came out to check, he set my bulk charge down to 53.8v instead of the 56v area that is normal for AGM and was adamant that it was right. I'm no expert, but I think that is LI battery settings. Doubt that is good, and didn't make any difference anyway. Was wondering if I should downgrade firmware and BMS back to the version @SiliconKid sent. Other than that, I am just going to send them in for RMA so they can test. But that could take months.

So the firmware update also fixes an issue with AGM batteries not discharging to the specified voltage and just cutting back to mains. The SOC is still very buggy, dropping to <50% after a PV starts charging the batteries again in the morning, but the voltage is still around 50v. Odd. At least now it's actually discharging to cutoff voltage instead of just going back to mains. Thanks again @SiliconKid

You're a legend, thanks man!

Can anyone forward me the firmware update? Not getting any reply from [email protected]

Very glad I found this forum, @SiliconKid Really appreciate the time you've put into this! It's a great help. Would you mind sending the firmware details to me? [email protected] Thanks!