I think I'm more annoyed with the green glow than anything else ?
Sixtysix 280ah Cells from Deligreen
- Thread starter ArthurEld
- Start date
I think I'm more annoyed with the green glow than anything else ?
ArthurEld
Solar Wizard
Yea it messes up the picture. I thought about turning it off.
While testing cells for weeks on end my neighbors probably wondered what that green glow was in my garage every night.
That configuration doesn't show much anyway.
I will post my cleaner serial setup today.
ArthurEld
Solar Wizard
Here's some pictures of my latest setup. This is an evolving work in progress.
I moved the BMS and shunt to the back so I could get all of the balance wires out of the way.
The + distribution bar has a 100A MRBF fuse. I'm still deciding what to do about Class T fuses.
I don't like the serrated flange nuts. Especially on the balance leads. Next time they come off will be the last time.
As you can see I covered more of my ratchet and socket.
My whole setup
Starting balanced from the bottom
I moved the BMS and shunt to the back so I could get all of the balance wires out of the way.
The + distribution bar has a 100A MRBF fuse. I'm still deciding what to do about Class T fuses.
I don't like the serrated flange nuts. Especially on the balance leads. Next time they come off will be the last time.
As you can see I covered more of my ratchet and socket.
My whole setup
Starting balanced from the bottom
Fallingaway
New Member
- Joined
- Mar 28, 2020
- Messages
- 144
Gorgeous! Looks like you’ve still got a lot of work to do too! Do you like the MPP? I’ve been leaning towards going that way.
Great set-up, I like the BMS app readout! What BMS are you using?
ArthurEld
Solar Wizard
Thanks. I really haven't gone overboard on making everything perfect. But I like neat and efficient.
I do like the MPP but to be honest, I bought it because I needed a 48V inverter. But 48V inverters cost 75% minimum of the cost of the MPP Solar 3048.
It has been great for a preview for the Solark that I expect to have in a couple weeks. And it is a handy unit to have for whatever might pop up.
I will probably find a perfect side use for it after my grid tied system is installed and inspected.
ArthurEld
Solar Wizard
It is the Heltec smart BMS with active balance.
ArthurEld
Solar Wizard
I made it to the upper voltage limit. This screenshot is from about 15 or 20 minutes after it hit the limit.
Cell 14 hit the limit but it has settled a lot already.
It is obvious that I would have to set the upper charge limit to 3.35V max if I wanted to leave the cells bottom balanced.
edit: charging was at 50A
At this point I check my restraining fixture torque and make sure the nuts are about 12-15 inch pounds. I had just snugged the nuts when at a low state of charge. I measure the corners of the fixture and adjust to torque slightly to try and keep the measurements the same. Generally the bottom has been fatter so it gets closer to 15 inch pounds.
The top will be 12 inch pounds. I adjust the torque to try and keep the two pieces of plywood parallel.
I don't know if all that helps anything but I am fairly sure it doesn't hurt anything.
The delta in this image is .102. I expect it to go down a lot by tomorrow. If I wanted to, I could turn on the balancer and it would balance it perfectly over night. But I don't think I need to do that this time.
As long as the delta is low, I will tear down the serial setup and connect parallel. If the delta is still too high, I will turn on the balancer.
I like the cell voltages to be close when I connect parallel or serial. And when I start charging/discharging, I start with low amps. Again, I don't know if it makes a difference but it can't hurt.
Next I will use my Riden power supply which does a wonderful job of top balancing without any attention.
Cell 14 hit the limit but it has settled a lot already.
It is obvious that I would have to set the upper charge limit to 3.35V max if I wanted to leave the cells bottom balanced.
edit: charging was at 50A
At this point I check my restraining fixture torque and make sure the nuts are about 12-15 inch pounds. I had just snugged the nuts when at a low state of charge. I measure the corners of the fixture and adjust to torque slightly to try and keep the measurements the same. Generally the bottom has been fatter so it gets closer to 15 inch pounds.
The top will be 12 inch pounds. I adjust the torque to try and keep the two pieces of plywood parallel.
I don't know if all that helps anything but I am fairly sure it doesn't hurt anything.
The delta in this image is .102. I expect it to go down a lot by tomorrow. If I wanted to, I could turn on the balancer and it would balance it perfectly over night. But I don't think I need to do that this time.
As long as the delta is low, I will tear down the serial setup and connect parallel. If the delta is still too high, I will turn on the balancer.
I like the cell voltages to be close when I connect parallel or serial. And when I start charging/discharging, I start with low amps. Again, I don't know if it makes a difference but it can't hurt.
Next I will use my Riden power supply which does a wonderful job of top balancing without any attention.
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So basically your cells at the top have around the same delta with after a bottom balance as mine do at the bottom after a top balance. Makes perfect sense to me.
I haven't taken any measurements but it's visually obvious to me my cells get fatter at the bottom too.
The Riden is a little gem for sure...
I haven't taken any measurements but it's visually obvious to me my cells get fatter at the bottom too.
The Riden is a little gem for sure...
ArthurEld
Solar Wizard
I assume they settle from weight. I don't know what is in there but my guess is that it is similar consistency to an aluminum prism filled with clay. But it expands and contracts. It's solid as hell but you can move it around a little by restraining the thickness and going through a few discharge/charge cycles.
This seems to be the case from what I have observed so far but other than that, I'm guessing and if I'm wrong it wouldn't be the first time.
These cells are weird that's for sure.
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X-rays and diagrams of prismatic cells can be found by a google search. I believe the cell contains a large jelly roll surrounded by a pouch and electrolyte. It still doesn't explain why the cell expands more at the bottom than the top. I am still waiting for someone to dissect one of the EVE's. But that will probably never happen.
ArthurEld
Solar Wizard
The jelly roll seems to be settling so I'm trying to squeeze it beck into shape.
ArthurEld
Solar Wizard
I've been thinking about how careful I have to be when moving busbars, tools and wires around and I realized the damn ring extends the connection of everything in that hand about 1". I hate when it takes me so long to think of these things.
michael d
off-grid solar pilgrim
I don't wear a ring but maybe the mechanics gloves without fingertips would be useful. gloves are somewhat cumbersome, so thin and flexible insulating gloves may still help to make assembly safer. I am definitely more careful after arc-ing a few cells (272Ah Lishen) and it ruining 2 studs.
Here it is on Amazon but available in many big box stores:
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Haven’t dropped by this thread in a while.
Looking good @ArthurEld !
ArthurEld
Solar Wizard
ArthurEld
Solar Wizard
I finished my top balance and tore done the parallel setup.
Now I will loctite my studs in before switching back to serial.
I'm using red Loctite 263 which is for studs. The studs are supposed to break off unless I heat them before trying to remove them.
I took all of the studs out and cleaned the holes and studs with acetone.
Then I added one drop of Loctite 263.
Even using one drop I still had to clean up a couple terminals when too much pushed out of the hole on to the terminal.
It appears to be wicking up the stud. That tells me it's wicking everywhere in the hole
I plan to wait 24 hours before I torque any nuts on these studs.
Now I will loctite my studs in before switching back to serial.
I'm using red Loctite 263 which is for studs. The studs are supposed to break off unless I heat them before trying to remove them.
I took all of the studs out and cleaned the holes and studs with acetone.
Then I added one drop of Loctite 263.
Even using one drop I still had to clean up a couple terminals when too much pushed out of the hole on to the terminal.
It appears to be wicking up the stud. That tells me it's wicking everywhere in the hole
I plan to wait 24 hours before I torque any nuts on these studs.
I ordered Loctite 263 earlier in the week. Plan on doing the same with my cells as a first action. Obviously keen to follow your progress ?
My cells are supposedly in Europe but UPS tracking is still not active. 60 days since I ordered today.
My cells are supposedly in Europe but UPS tracking is still not active. 60 days since I ordered today.
ArthurEld
Solar Wizard
It's always better to learn from someone else's mistakes
ArthurEld
Solar Wizard
Well, since the loctite is wicking up the screw, guess what? It's wicking on the terminals.
I can see a little but I will clean all of the terminals with acetone and scotchbrite and wipe a little noalox on
I can see a little but I will clean all of the terminals with acetone and scotchbrite and wipe a little noalox on
