diy solar

diy solar

Very new to solar but started purchasing items, not sure of the final specs of the whole system.

I completed the first 64 with no issues, there is a large delta from what is shown to what the actual output is. From the front to the back you have a 1.2 to 1.4v delta. I would think a common mistake would have been for some to turn up the the voltage and not pay attention to when it stops. Throughout the charging I would adjust the voltage till it stopped then backed it down by .5 this kept it from running away and was very stable during the top balance on the first 64. I was up till almost 3:00am monitoring the batteries on the final leg. This battery that swelled was not charged or discharged it was merely in a bank of 64 wating to be top charged.
My experience, I've had two cells (maybe more, haven't tested all of them yet) that took less than 6 amp hours total to go from 3.33 volts to 3.65 volts. At 40 amp hours going in, that's less than 10 minutes. Yes, the voltage measured at the back is different. I'm just trying to explain, that ESPECIALLY with a 40 amp current, you can over charge a cell in less than 10 minutes. The correct way to do it, is to disconnect the cell or bank of cells, set the power supply to 3.65 volts or as close as you can get it, then hook up the cell or group of cells. Then you can adjust the current, and if it doesn't read 40 amps, it doesn't mean anything is wrong. Tweaking the output voltage to 3.9 in order to get the supply to output 40 amps means you can overcharge a cell in 9 minutes (obviously longer if you have a lot in parallel). Lower amperage supplies will take longer, but I would STRONGLY encourage people to set voltage to 3.65 without a cell attached, and then leave it. It's perfectly OK to have the supply output less amps, and is expected.
 
Last edited:
Per local law we have to keep the water at 110f,
I love mine. I set the temperature at 125 F but use a tempering valve so that water in pipes does not exceed 110 F.
I had a similar issue with leaking and concluded I needed to use more pipe dope & teflon tape. I blamed it on the brass fitting. It takes two to tango.
 
My experience, I've had two cells (maybe more, haven't tested all of them yet) that took less than 6 amp hours total to go from 3.33 volts to 3.65 volts. At 40 amp hours going in, that's less than 10 minutes. Yes, the voltage measured at the back is different. I'm just trying to explain, that ESPECIALLY with a 40 amp current, you can over charge a cell in less than 10 minutes. The correct way to do it, is to disconnect the cell or bank of cells, set the power supply to 3.65 volts or as close as you can get it, then hook up the cell or group of cells. Then you can adjust the current, and if it doesn't read 40 amps, it doesn't mean anything is wrong. Tweaking the output voltage to 3.9 in order to get the supply to output 40 amps means you can overcharge a cell in 9 minutes (obviously longer if you have a lot in parallel). Lower amperage supplies will take longer, but I would STRONGLY encourage people to set voltage to 3.65 without a cell attached, and the leave it. It's perfectly OK to have the supply output less amps, and is expected.
I agree with you 100% on that it would charge very quickly with a few cells but there are 64 connected. I have not tried setting it to 3.65v and then hooking the bank up, I was so concerned with over charging I moved the laptop and a tv by them so I could watch them closely after I went by 3.6v.
 
I guess that will be a case of spontaneous puffiness.
Seeing how much one can expand and its recommend to slightly compress them which I was going to do. I now wonder could a cell expanding damage the surrounding cells?
 
If not clamped, its expansion could cause the busbar to pull out the terminal of an adjacent cell. Anything is possible. This is the first case of spontaneous puffiness.
I have no issues admitting my mistakes but I had not touched any of those batteries in that bank, only lined them up. That makes sense with that much expansion I can see it damaging the terminals.
 
Seeing how much one can expand and its recommend to slightly compress them which I was going to do. I now wonder could a cell expanding damage the surrounding cells?
Personally, I'm thinking the recommendation to clamp cells in a fixture and the high specification for torque on the terminals (which are blank from the manufacturer) are for exactly this reason, to prevent expansion and contraction of the cells from ripping busbars and terminals out of the cell. We'd have to actually speak to the manufacturer to find out, but these seem primarily designed for bus or trolley use, and that would make sense. Put them in a fixture to try and prevent vibrations and expansion and contraction from pulling the busbars loose, or worse yet, ripping the internal connections to the terminals from the "jelly roll". The torque specification is obviously not how much torque should be used to screw in a busbar, I'm thinking it is how much torque a terminal can withstand without tearing up the cell internally. I'm actually thinking most of these are manufacturing rejects, that don't meet some aspect of the specification for grade "A" cells. Most likely the initial charge at the factory didn't put more than 280 (or whatever) amp hours into the cell. That's what many of mine look like, anyway.
 
Personally, I'm thinking the recommendation to clamp cells in a fixture and the high specification for torque on the terminals (which are blank from the manufacturer) are for exactly this reason, to prevent expansion and contraction of the cells from ripping busbars and terminals out of the cell. We'd have to actually speak to the manufacturer to find out, but these seem primarily designed for bus or trolley use, and that would make sense. Put them in a fixture to try and prevent vibrations and expansion and contraction from pulling the busbars loose, or worse yet, ripping the internal connections to the terminals from the "jelly roll". The torque specification is obviously not how much torque should be used to screw in a busbar, I'm thinking it is how much torque a terminal can withstand without tearing up the cell internally. I'm actually thinking most of these are manufacturing rejects, that don't meet some aspect of the specification for grade "A" cells. Most likely the initial charge at the factory didn't put more than 280 (or whatever) amp hours into the cell. That's what many of mine look like, anyway.
I'm still undecided on the type of compression to use since the bank will be a 4p16s.
 
If only one out of 128 went bad that is within the risk that I accepted when I purchased my 48 cells.
The packaging was superb on one box bulk of the side was punctured and the battery had no visibly deformation. I have not mention the seller yet as I have not been able to use due to the length of time to find a decent charger. But hope to provide a review for them when I'm able to test the batteries.
 
Moved the bus bars over and started on the second bank.
 

Attachments

  • P1220553.JPG
    P1220553.JPG
    77.3 KB · Views: 46
My order with onlinemetals went very well, they have impeccable customer service and return calls which is excellent. I have no issues with recommending them for purchases. Here's a few screenshots, I'm holding off drilling till the packs are assemble and I verify my templates still fit properly.
 

Attachments

  • P1220559.JPG
    P1220559.JPG
    50.5 KB · Views: 25
  • P1220558.JPG
    P1220558.JPG
    51.4 KB · Views: 23
  • P1220557.JPG
    P1220557.JPG
    52.3 KB · Views: 23
  • P1220556.JPG
    P1220556.JPG
    48.8 KB · Views: 25
I don't understand why the two wires are connected to the positive terminals? How are they connected to your charger? Are there two more at the other end going to negative terminals?
There are the charger is at the other end.
 
My order with onlinemetals went very well, they have impeccable customer service and return calls which is excellent. I have no issues with recommending them for purchases. Here's a few screenshots, I'm holding off drilling till the packs are assemble and I verify my templates still fit properly.
Nice, I take it you went with nickel or silver plating, and had them cut to length? I went with the copper unplated, and didn't have anything cut.
FYI, I have the same area rug. :)
 
I love mine. I set the temperature at 125 F but use a tempering valve so that water in pipes does not exceed 110 F.
I had a similar issue with leaking and concluded I needed to use more pipe dope & teflon tape. I blamed it on the brass fitting. It takes two to tango.
On this unit all the in and out connections are done at the factory and they specifically state that the black lines should not move when installing the lines. So the lower unit is out of spec per Rheem as I had turn it way past where they state it should already be leak proof. I will update on what Rheem comes back with in regards to my system as the leak sensor is down in the pan due to the faulty brass fitting installed at the factory.
 
Back
Top